A method of capturing nucleic acids

Abstract

The present invention relates to a method of capturing nucleic acids from an aqueous sample, including providing an apparatus configured to capture the nucleic acids from the aqueous sample, wherein the apparatus comprises a substrate which is a copolymer or is provided with said copolymer, the copolymer comprising nucleobase- containing moieties, positively charged moieties at pH from 2 to 11 adapted to bind the nucleic acids via electrostatic interaction, and uncharged moieties, and wherein the aqueous sample is selected from environmental water samples, industrial water samples, wastewater samples, and excretory fluid samples. The method further includes contacting the aqueous sample comprising the nucleic acids with the nucleobase-containing copolymer, and allowing the nucleic acids to bind to the nucleobase-containing copolymer thereby capturing said nucleic acids by said copolymer. The present invention also relates to the copolymer and the apparatus.

Description

A METHOD OF CAPTURING NUCLEIC ACIDSField of the inventionThe present invention is in the technical field of capturing nucleic acids from an aqueous sample.Background of the inventionNucleic acids (e.g. DNA) provide valuable insights for a range of analyses, from simple detection and quantification to complex genetic profiling using advanced sequencing and bioinformatics approaches. These analyses have significantly impacted monitoring and diagnostic capabilities, such as pregnancy evaluation, cancer detection, transplantation monitoring, infection diagnosis, and toxicology assessments. Beyond health diagnostics, nucleic acids captured from various sources can contribute to environmental monitoring, screening, diagnosis, profiling, and industrial processes.In health diagnostics, nucleic acids (e.g. DNA) captured from excretory fluids like urine are particularly useful. Urinary DNA consists of two primary populations that can be analysed either together or separately. The first source is DNA recovered from cells in the urine, typically originating from the genitourinary tract, which is effective for describing local diseases or infections. The second source is cell-free DNA (cfDNA), which is passively released from dead or dying cells or actively released from living cells. This cfDNA includes genetic material from both genitourinary and non-genitourinary tissues. Transrenal cfDNA fragments, processed through glomerular filtration in the kidneys, can originate from any part of the body, offering a broad spectrum of genetic information.Capturing DNA from urine typically involves using extraction kits which usually handle volumes ranging from 0.5mL to 10mL, with some capable of processing up to 80mL. The ability to process larger urine volumes generally results in greater DNA recovery, thereby enhancing subsequent analysis.There is a continuous need to improve nucleic acid recovery techniques from urine and other excretory fluids. Enhancements in extraction efficiency and the ability to process larger sample volumes are particularly desirable. Additionally, flexibility in nucleic acid recovery in various settings, including point-of-care environments and home settings, is important due to the private nature of excretory fluid collection. Point-of-care testing conducted close to the site of patient treatment is particularly beneficial. This may provide rapid turnaround of test results so that appropriate treatment can be implemented, leading to improved clinical outcomes. Improving nucleic acid recovery techniques may allow various health professionals and, in some cases, patients themselves to perform (part of) the test process, increasing accessibility and convenience, especially in remote or resource-limited areas.Beyond human health applications, nucleic acid recovery has significant potential in other fields. For example, efficient nucleic acid recovery from aquaculture water can provide valuable insights into disease management, improving aquatic animal health and productivity. Nucleic acid analysis can also serve industries such as forensics, bio surveillance, brewery / fermentation processes, bioreactors, and wastewater management. These applications often require the capture of nucleic acids from diverse sources, including cell-free DNA from living organisms, injured or dead organisms, laboratory lysis of cells or tissues, microorganisms, and invasive species. Developing efficient techniques to capture nucleic acids can significantly enhance monitoring and diagnostic capabilities, contributing to improved health outcomes, environmental monitoring, and industrial processes.It is in this context that the present invention has been devised.Summary of the inventionThe present invention provides a method of capturing nucleic acids from an aqueous sample, comprising: providing an apparatus configured to capture the nucleic acids from the aqueous sample, wherein the apparatus comprises a substrate which is a copolymer or is provided with said copolymer, the copolymer comprising nucleobase- containing moieties, positively charged moieties at pH from 2 to 11 adapted to bind the nucleic acids via electrostatic interaction, and uncharged moieties; contacting the aqueous sample comprising the nucleic acids with the nucleobase-containing copolymer comprised in the apparatus; and allowing the nucleic acids to bind to the nucleobase-containing copolymer thereby capturing said nucleic acids by said copolymer. The aqueous sample is selected from environmental water samples, industrial water samples, wastewater samples and excretory fluid samples.Typically, the aqueous sample refers to excretory fluid sample such as urinary sample (e.g. human or animal urine, particularly human urine). The nucleic acid may comprise (e.g. be) urinary DNA, such as cfDNA (e.g. urinary cfDNA).Aqueous sample refers to sample containing water, optionally containing from 80% to 99.9% water by weight of the total sample, or from 90% to 99.5%, or from 95% to 99%.Environmental water typically encompasses water from natural bodies (e.g. rivers, lakes, oceans, ponds, underground, and groundwater). It may include water from manmade or controlled, or influenced bodies (e.g. aquarium, aquaculture water, cultivation water, and reservoirs). Environmental water samples may be selected from natural water samples, aquaculture water samples, cultivation water samples, and mixtures thereof.Industrial water samples may refer to water samples from industrial processes such as brewing, fermentation, and bioreactor operations.Wastewater typically refers to used water from domestic, industrial, commercial or agricultural activities, surface runoff water, storm water, or sewage. Wastewater samples may be obtained from wastewater treatment facilities or management processes.Excretory fluid typically refers to bodily or biological fluid expelled from the body as waste (e.g. urine). Excretory fluid sample may refer to urine sample (e.g. human oranimal urine). It will be understood that the excretory fluid sample is an extracorporeal sample (i.e. sample outside the human or animal body).It may be that the aqueous sample does not contain blood or plasma or serum, such as whole blood.The copolymer is a nucleobase-containing copolymer further comprising two different moieties: the positively charged moieties and the uncharged moieties. The substrate may be formed of the nucleobase-containing copolymer. Alternatively, the substrate may be formed of a different material (e.g. polyurethane) and said substrate may be provided with the nucleobase-containing copolymer. For instance, said substrate may be coated by the nucleobase-containing copolymer.The nucleobase-containing copolymer provides (e.g. contains) positively charged moieties (e.g. monomers) at pH from 2 to 11 (e.g. a physiological pH). Said positively charged moieties are adapted to electrostatically interact with the nucleic acids. It may be that the nucleobase-containing copolymer is adapted to interact with the nucleic acids via hydrogen bonding. Said copolymer may bind the nucleic acids through electrostatic interaction, hydrogen bonding or through the synergistic hydrogen bonding and electrostatic interactions. The nucleic acids can thus be retained on the substrate (made of said copolymer or is provided with said copolymer). The binding may optionally be reversed through use of an elution process to recover the nucleic acids ready for testing. The method may be a method of collecting and / or recovering the nucleic acids (e.g. apparatus is configured to collect and / or recover a nucleic acid from a sample). ‘Recovery’, ‘recovering’ or ‘recovered’ refers to releasing at least part of the captured nucleic acids optionally all of the captured nucleic acids (for subsequent analysis).It may be that the apparatus is configured to release at least part of and optionally all of the captured nucleic acids (for subsequent analyses). It may be that the apparatus is configured to reversibly capture the nucleic acids. The invention may provide a method of reversibly capturing the nucleic acids. The captured nucleic acids may be eluted from the copolymer (e.g. from the apparatus).It may be that following capture, the nucleic acids are at least partially (optionally fully) separated and / or removed from the apparatus. An additional step of releasing at least some of the captured nucleic acids from the apparatus may be included. The methodmay comprise eluting the captured nucleic acids from the nucleobase-containing copolymer. Optionally, the released nucleic acid is purified. Optionally, the method comprises purifying the released nucleic acid.The inclusion of the nucleobase-containing copolymer greatly enhances the interaction between the apparatus and the nucleic acids present in the aqueous sample. This improvement results in more effective nucleic acid capture and recovery. Consequently, the use of the nucleobase-containing copolymer increases the efficiency of the apparatus, ensuring great performance in isolating nucleic acids from the aqueous sample. This leads to more reliable and consistent results from the subsequent analysis, making the apparatus more effective for various applications involving nucleic acid extraction and analysis.The present invention may provide the nucleobase-containing copolymer, as described herein. In addition to the nucleobase-containing moieties, the copolymer contains (other) positively charged moieties at pH from 2 to 11. Said moieties are adapted to bind the nucleic acids via electrostatic interaction. Further, the copolymer contains moieties that are uncharged. Therefore, the copolymer contains at least three different moieties. Herein, the pH normally refers to a pH of from 2 to 11, or from 3 to 10, or from 4 to 9, or from 5 to 7. The pH may be a physiological pH (e.g. from 2 to 11 , or from 3 to 10, or from 4 to 9, or from 5 to 7). Positively charged moieties refer to moieties that are positively charged or capable of becoming positively charged (e.g. cationic moieties) at the said pH. In the context of the present invention, it will be understood that the copolymer may be a positively charged copolymer at the said pH. ‘Positively charged’ should be understood to mean that the overall charge is positive. It is possible that the copolymer is free from negatively charged moieties, typically at the said pH. The moieties that are uncharged may refer to moieties uncharged at the said pH. It will be further understood that the substrate of the present invention may be positively charged, typically at the said pH. It is because the substrate is either the copolymer or is provided with said copolymer.It may be that the molar proportion of said uncharged moieties is at least 4 times that of said positively charged moieties, or at least 6 times, or at least 8 times. It has been identified that a higher molar ratio of the uncharged moieties to positively charged moieties provides better nucleic acid recovery from the aqueous sample.It may be that the logarithm of partition coefficient (LogP) of the nucleobase-containing copolymer is less than 0.83, or less than 0.7, or less than 0.6, or less than 0. It may be that the nucleobase-containing copolymer is a hydrophilic copolymer. A negative value for log * means the material has a higher affinity for the aqueous phase (more hydrophilic); when logP^O the material is equally partitioned between the aqueous and non-aqueous (e.g. lipid) phases; and a positive value for log / denotes a higher concentration in the non-aqueous (e.g. lipid) phase, meaning the material is more lipophilic. For instance, Log A means there is a 10:1 partition in lipid: aqueous phases. In the context of the present invention, a more hydrophilic polymer tends to recover more nucleic acids.The logarithm of partition coefficient (LogP) value can be measured using known methods such as Shake Flask and HPLC. The value can also be obtained by using software such as ACD / Log / 9(e.g. ACG / Percepta version 14.02 by Advanced Chemistry Development, Inc. Toronto, ON, Canada) using algorithms to calculate the log / 9of a material by the sum of its fragments (i.e. log / 9values for individual fragments are obtained from experimental data and / or determined statistically). Alternatively, log / 9may be obtained using ChemDraw Prime software (v22.2.0.3300) for each of the monomers. These are then calculated for the resulting copolymers based on the monomer feedstock by the equation:Log / 9;opolymer—Xi=i Cl LogP I wherein Ci is the molar proportion of the monomer species in the feedstock, and LogP i is the partition coefficient value for the monomer species.Typically, the nucleobase-containing copolymer comprises a backbone with at least a proportion of side chains being nucleobase side chains.It may be that each of the nucleobase side chains comprises one or more nucleobases, independently selected from natural nucleobases, unnatural nucleobases, modified nucleobases wherein the modification allows interaction with nucleic acid via hydrogen bonding and / or electrostatic binding, and mixtures thereof. Suitable examples of the nucleobases include but are not limited to purine nucleobases, pyrimidine nucleobases, and mixtures thereof, wherein the nucleobases are optionally modified to allow the interaction as described above. The modified purine nucleobase may bebased on a modified adenosine or guanosine structure. The modified pyrimidine nucleobase may be based on a modified cytosine, thymine or uridine structure.It may be that each of the nucleobase side chains comprises one or more nucleobases, independently selected from adenine (A), cytosine (C), guanine (G), thymine (T), uracil (U), derivatives of ACGTU thereof and mixtures thereof. Derivatives of ACGTU include but are not limited to aminoadenine, aminocytosine, aminoguanine, aminothymine, aminouracil, purine, pyrimidine, hypoxanthine, xanthine, theophylline, theobromine, caffeine, uric acid, isoguanine, 7-methylguanine, 5,6, dihydrouracil, 5-methyl cytosine, 5-hydroxymethylcytosine, 3-Nitropyrrole, 5-Nitroindole, 2,6-diaminopurine, 6, 8 diaminopurine, pyrene, fluorouracil, barbituric acid, orotic acid, a salt or ester of ACGTU, a compound that releases one or more ACGTUs during use, a compound that comprises one or more ACGTUs, and mixtures thereof. It may be that the nucleobase side chains comprise cytosine or thymine or a combination thereof.Typically, the molar proportion of side chains of the copolymer comprising one or more nucleobases may be at least 1%, or at least 5%, or at least 10%, but not more than 20%, or not more than 15%. In preferred embodiments, each of the nucleobase side chains comprises one or more nucleobases independently selected from ACGTU, derivatives of ACGTU thereof and mixtures thereof, and the molar proportion of total said side chains of the copolymer is from 1 % to 20%, or from 2% to 15%, or from 5% to 15%.Without wishing to be bound by any theory, it is believed that the nucleobase enables base-pairing of the copolymer to a nucleic acid. Thus, the copolymer can capture (e.g. bind) the nucleic acid from an aqueous sample. A nucleobase may allow base pairing via hydrogen bonding typically with additional electrostatic interaction, for example double or triple hydrogen bonding between amine and carbonyl groups provided on the nucleic acid and the polymer. The electrostatic interactions may be provided via tertiary ammonium ions on the copolymer and phosphate esters on the nucleic acid.Optionally, the nucleic acid is reversibly captured by the copolymer via hydrogen bonding and / or electrostatic interaction. The nucleic acid may be released (e.g. in a recovery process) for further analysis when needed.Additionally and optionally, the side chains of the copolymer backbone comprise one or more of the followings: amines, amides, alcohols, carboxylic acids, alkanes, alkenes,alkynes, esters, ethers, epoxies, sulfonyl hydrides, sulfonyls, thiols, heterocycles, homocycles, aromatic cycles, anti-aromatic cycles, derivatives thereof, or combinations thereof.It may be that the copolymer comprises (e.g. consists of): (i) (meth)acrylate-based monomers with nucleobase side chains, (ii) (meth)acrylate-based monomers with amine side chains, and (iii) uncharged, (meth)acrylate-based monomers. The copolymer may comprise (e.g. consist of) 1-10% monomers (i), 5-50% monomers (ii), and 40-90% monomers (iii). It may be that the copolymer comprises (e.g. consists of) 1-5% monomers (i), 5-15% monomers (ii), and 80-90% monomers (iii). The percentages herein refer to the molar proportions of the monomers comprised in the copolymer.It will be understood that monomers (i) typically provide (e.g. contain) the nucleobase- containing moieties. Monomers (ii) and (iii) typically provide (e.g. contain) the positively charged moieties and uncharged moieties, respectively.It may be that the monomers (i) are selected from thymine ethyl acrylate (ThEA), thymine acetoxyethyl methacrylate (ThAcMA), cytosine ethyl acrylate (CyEA), and mixtures thereof.It may be that the monomers (ii) are selected from diethylamino ethyl acrylate (DEAEA), diethylamino ethyl methacrylate (DEAEMA), N-(3- aminopropyl)methacrylamide hydrochloride (APMAA), N-(3-aminopropyl)acrylamide hydrochloride (APAA), 3-(dimethyl-amino)propyl acrylate (DMAPA), N,N-diethyl acrylamide (DEAA), and mixtures thereof, preferably selected from DEAEA, DEAEMA, APMAA, APAA and mixtures thereof.Monomers (ii) comprises amine side chains, optionally primary amine side chains, or dialkyl amine side chains (e.g. diethyl or dimethyl amine side chains). At the abovedescribed pH (e.g. a physiological pH), the positively charged moieties may be quaternary ammonium salts or quaternary phosphonium salts, preferably quaternary ammonium salts. Typically, the copolymer comprises one or more amines (e.g. primary amine, diethyl amine) that can provide a positive charge at the abovedescribed pH (e.g. a physiological pH), more typically one or more amine side chains (e.g. primary amine side chains, diethyl amine side chains). The positively charged moieties may attract negatively charged groups (e.g. phosphate) on nucleic acid.Typically, the copolymer comprises at least 5% amine side chains (e.g. primary or diethyl amine side chains) or at least 8%, or at least 10%, or at least 20%, but not more than 40%, or not more than 30%, in which the percentages refer to molar percentages with respect to the whole copolymer.It may be that the monomers (iii) are selected from 2-methoxyethyl acrylate (MEA), 2- methoxyethyl methacrylate (MEMA), 2-hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), 2-phenoxy-ethyl methacrylate (PhEMA), 2-phenoxy-ethyl acrylate (PhEA), methyl methacrylate (MMA), methyl acrylate (MA), methacrylic acid (MA-H), acrylic acid (A-H), polyethylene glycol) monomethyl ether acrylate (PEGA), poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), ethylene glycol dimethacrylate (EGDMA), ethylene glycol acrylate, and mixtures thereof.Typically, the copolymer is formed from (meth)acrylate-based monomers, as described herein. The copolymer may be a terpolymer, or a tetrapolymer, or a pentapolymer, or a hexapolymer. Typically, the copolymer is a tetrapolymer or a pentapolymer or a hexapolymer, more typically a pentapolymer or a hexapolymer. Typically, the copolymer of the present invention comprises the monomers (ii) and (iii), as selected above and (meth) acrylate-based monomers with nucleobase side chains. The (meth)acrylate-based monomers with nucleobase side chains may be selected from thymine ethyl acrylate (ThEA), thymine acetoxyethyl methacrylate (ThAcMA), cytosine ethyl acrylate (CyEA), and mixtures thereof, optionally from ThEA, CyEA, and mixtures thereof. The selection of MEA, MEMA, PEGMA, PEGA and mixtures thereof as monomers (iii) is particularly preferred since they provide good resistance to biofouling. The (meth)acrylate-based monomers with polyethylene glycol) side chains (e.g. PEGA, PEGMA) used in the present invention may be of the same or different molecular weight. Monomers (iii) are structural, uncharged monomers (at the abovedescribed pH). Monomers (ii) may be selected from diethylamino ethylacrylate (DEAEA), diethylamino ethyl methacrylate (DEAEMA), N-(3- aminopropyl)methacrylamide hydrochloride (APMAA), N-(3-aminopropyl)acrylamide hydrochloride (APAA), and mixtures thereof, optionally selected from APMAA, DEAEA, and mixtures thereof.It may be that the monomers (i) are selected from ThEA, CyEA, and mixtures thereof, the monomers (ii) are selected from DEAEA, DEAEMA, APMAA, APAA, DEAA, DMAPA, and mixtures thereof, and the monomers (iii) are selected from MEA, MEMA, PEGA, PEGMA, HEMA, PhEMA, MA-H, EGDMA and mixtures thereof.It may be that the copolymer comprises (e.g. consists of) 40-90% (e.g. 70-90%) monomers (iii) comprising MEMA, MEA and PEGA, in combination with 1-10% (e.g. 1- 5%) monomer (i) comprising CyEA and ThEA, and 5-50% (e.g. 5-30%) monomer (ii) comprising DEAEA or DEAEMA or a mixture thereof. It may be that the copolymer comprises (e.g. consists of) 40%-60% MEMA, 20-50% MEA, 0.5-5% PEGA, 0.5- 5%CyEA, 0.5-5%ThEA, and 5-30% (e.g. 5-20%) DEAEA or DEAEMA or a mixture thereof.It may be that the copolymer comprises (e.g. consists of) 40-90% (e.g. 70-90%) monomers (iii) comprising MEMA, MEA and PEGA, in combination with 1-10% (e.g. 1- 5%) monomer (i) comprising ThEA and 5-50% (e.g. 5-30%) monomer (ii) comprising APMAA or APAA or a mixture thereof. It may be that the copolymer comprises (e.g. consists of) 40-60% MEMA, 20-50% MEA, 0.5-5% PEGA, 0.5-5% ThEA, and 5-30% (e.g. 5-20%) APMAA or APAA or a mixture thereof.The percentages of the copolymer components described herein are all molar proportions with respect to the whole copolymer.The copolymer may be a linear copolymer, a branched copolymer, a cross-linked copolymer, or a networked copolymer. Typically, the copolymer is a cross-linked copolymer or a networked copolymer. Networked copolymer may be a type of polymer where the individual polymer chains are connected by covalent bonds to form a three- dimensional network.The copolymer may be an ABA triblock copolymer, wherein blocks A comprise the uncharged moieties and the nucleobase-containing moieties, and blocks B comprises the positively charged moieties at pH from 2 to 11 , adapted to bind the nucleic acid via electrostatic interaction.It may be that blocks A comprise (e.g. consist of) monomers (i) and (iii) as described herein, and blocks B comprise (e.g. consist of) monomers (ii) as described herein.It may be that blocks A comprise (e.g. consist of) MEMA, MEA, ThEA and PEGA, and blocks B comprises (e.g. consist of) DEAEA, optionally the copolymer comprising (e.g. consisting of) 1-10% ThEA, 5-20% DEAEA, and 70-90% MEMA, MEA and PEGA.Optionally, the copolymer has one of the following compositions as indicated in Table 1 below.Table 1DEAEA-X-BLOCK corresponds to the ABA triblock copolymer as described herein. BRANCHED-X-DP300 and BRANCHED-X-DP50 are crossed-linked copolymers having degree of polymerization of 300 and 50 respectively.Optionally, the copolymer is selected from (a group consisting of) DEAEA50-26, ThEA5-X, DEAEA-X-BLOCK, BRANCHED-X-DP300, BRANCHED-X-DP50, CyEA1- X-SWAP, CyEA5-X, TyCy1-X, APMAA10-X-SWAP, HEMA10-X, PhEMA10-X, MA- H10-X, and MEMA-X-SWAP.Optionally, the copolymer is selected from (a group consisting of) DEAEA-X-BLOCK, TyCy1-X, and APMAA10-X-SWAP.The composition of the copolymer can be determined by1H NMR. The percentages are molar proportions with respect to the whole copolymer, calculated based on the following method. 5 mg (± 0.5) copolymer in 600 pL deuterated dimethyl sulfoxide was submitted for1H NMR analysis. The resulting spectrum was recorded using a Broker AVA-500 at 500 MHz and 298 K. The broad peak corresponding to 2H (3.80-4.30 ppm) on the carbon beta to the carboxylate on copolymer side chains was set to represent 100% of the monomer components. This peak was shared by all monomers incorporated in the copolymer. The spectrum was registered to its solvent peak and subsequently analysed for broad peaks at chemical shifts indicative of each type of polymerised monomer. Individual monomer components were identified in reference to pure monomer samples, integrated, and calculated as a proportion of all monomer components. For the copolymers in Table 1 , the identified peaks were grouped and integrated. The percentage contribution for each of those monomers was then calculated based on integration of the proportion of signal from each monomer as part of the copolymer signal as a whole. The method described herein can be referred to as ‘H-NMR Method’, and where applicable, it can be used to determine percentages of copolymer components mentioned elsewhere in the specification.Suitably, Mn value of PEGA used to prepare the copolymer is about 480. Any mixtures of the copolymers described above can also be used in the present invention.Optionally, the copolymer has a molecular weight from 1 kDa to 500 kDa. Optionally, the molecular weight of the polymer is at least 10 kDa, or at least 20 kDa, or at least 30 kDa, but not more than 100 kDa, or not more than 60 kDa, or not more than 50 kDa.The copolymers may be prepared by known and effective methods to those skilled in the art. The copolymer may be prepared by vinyl polymerisation. Suitably, the copolymer is prepared by RAFT polymerisation. The invention may provide a method of making the copolymer comprising preparing the nucleobase-containing copolymer, preferably by RAFT polymerisation. Suitable crosslinkers (e.g. di or tri ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, butylene glycol di methacrylate) may be used if the copolymer is crossed linked. The synthesis may be a two-step polymerization process. The pre-polymerization phase comprises polymerization of monomers without crosslinkers to form linear or branched copolymers. This allows for controlled growth of polymer chains without immediate crosslinking. The postpolymerization crosslinking phase comprises adding crosslinker, typically after a certain amount of pre-polymerization time (e.g. after more than 3 hours). This mayallow for better control over the molecular weight and structure of the prepolymerization prior to crosslinking which may result in more uniform crosslinking. This may also achieve other properties (e.g. thermal, swelling properties, viscosity) of the final copolymer by controlling the timing of crosslinking. By way of example, BRANCHED-X-DP300 and BRANCHED-X-DP50 are both crossed-linked copolymers (having degree of polymerization of 300 and 50 respectively). EGDMA is the crosslinker used to prepare these polymers. BRANCHED - X-DP300 and BRANCHED -X-DP50 may be prepared from a mixture (e.g. a pre-polymerization mixture) comprising MEMA, DEAEA, MEA, PEGA and ThEA (e.g. 51% MEMA, 10%DEAEA, 37% MEA, 1% ThEA and 1 % PEGA, totalling 100% of the mixture), wherein the mixture is polymerised and reacted with 2% crosslinker EGDMA. Herein, the percentages refer to the molar proportions (e.g. 2% refers to 2% EGDMA by molar proportion of the total pre-polymerisation mixture). The final polymer compositions of BRANCHED-X-DP300 and BRANCHED-X-DP50 are as described in Table 1.The crosslinked copolymers (e.g. BRANCHED - X-DP300 and BRANCHED -X-DP50) may be star-shaped copolymers.In the context of the present invention, the substrate may be provided with the nucleobase-containing copolymer. The copolymer may be firstly dissolved in a solvent. The invention may provide a method of making the apparatus comprising: (i) making a nucleobase-containing copolymer preferably by RAFT polymerisation; (ii) optionally dissolving the copolymer into a solvent; (iii) treating a substrate with the copolymer, optionally the dissolved copolymer; and optionally (iv) treating the substrate provided with the polymer obtained in step (iii) with ethylene oxide. The solvent is preferably an organic solvent (e.g., tetrahydrofuran (THE)). The copolymer concentration is suitably at least 0.01 w / v% (weight per volume percentage concentration, 0.01g / 100mL), or at least 0.1 w / v%, or at least 0.5 w / v%, or at least 1 w / v%, optionally not more than 10 w / v%, or not more than 5 w / v%, or not more than 1 w / v%, or not more than 0.5 w / v%. Typically, a dissolved copolymer is used to treat the substrate.It may be that the substrate and / or the copolymer is treated with ethylene oxide (EtO). This may result in the substrate and / or the copolymer comprising one or more ethylene glycol units, preferably at least some of said units being in the form of polyethylene glycol (PEG). Normally, the treatment is compliant with ISO 11135-1 :2007 on the standardization of ethylene oxide sterilization of healthcare products. Herein, by‘ethylene oxide’ is meant a cyclic ether which is normally a colourless gas (e.g. at 1 atm and at ambient temperature which is 20-25°C).When ethylene oxide is used to treat the substrate and / or the copolymer, it can effectively kill the microorganisms that would otherwise pose a health risk. In other words, ethylene oxide treatment can provide effective sterilisation (possibly due to its excellent microbicidal activity). Moreover, it is surprisingly found that ethylene oxide can preserve or boost the capture as well as recovery of nucleic acid. This is in stark contrast to other sterilization methods (e.g. gamma radiation) which negatively affect the efficacy of the apparatus.Without wishing to be bound by any theory, it is believed that ethylene oxide preserves or promotes interaction between the nucleic acid and the apparatus. It is possible that ethylene oxide creates a beneficial change in the copolymer and / or the substrate (e.g. the substrate provided with the copolymer) to improve interaction with the nucleic acid. It is possible that ethylene oxide promotes compositional change of the substrate and / or the copolymer. The substrate and / or the copolymer may be modified by ethylene oxide. One or more surface properties of the substrate and / or copolymer may be modified to preserve or promote said interaction. It is possible that a plurality of EtO units graft to the copolymer and / or the substrate to increase their hydrophilicity. This increased hydrophilicity may occlude other components from the aqueous sample from interacting with the copolymer and / or substrate and allow hydrophilic nucleic acid (e.g. DNA) to reach the apparatus more quickly and interact with the copolymer and / or the substrate more successfully. For example, it is possible that ethylene oxide creates a compositional change in the polymer to make it more hydrophilic, thus pushing away the plasma protein but draws in hydrophilic DNA (e.g. cfDNA); and / or the ethylene oxide introduces a molecular crowding that promotes DNA (e.g. cfDNA) adsorption onto surfaces of the copolymer and / or the substrate. Thus, it is possible that ethylene oxide units take the form of PEG which exhibits a ‘molecular crowding’ effect that brings nucleic acid into close contact with the copolymer and / or substrate to increase efficacy of the apparatus. The conditions of the ethylene oxide treatment can be tuned (e.g. enhanced) to further improve the nucleic acid recovery. It is believed that under enhanced conditions, ethylene oxide can modify the substrate and / or the copolymer to a greater extent in favour of interaction with nucleic acid. The resultant apparatus is not only sterilised, but also effective in capturing as well as recovering nucleic acid (e.g. DNA).Typically, the substrate and / or the copolymer (e.g. the substrate provided with the copolymer) is treated (e.g. modified) by ethylene oxide applied from an ethylene oxide / diluent mixture, wherein optionally the ethylene oxide concentration is at least 100mg / L, or at least 200mg / L, or at least 300mg / L, or at least 400mg / L, or at least 800mg / L, or at least 1000mg / L. Optionally, the ethylene oxide concentration may be not more than 2000mg / L, or not more than 1600mg / L, or not more than 1500mg / L, or not more than 1200mg / L, or not more than 1000mg / L. For example, the ethylene oxide concentration may be from 300mg / L to 2000mg / L, or from 400mg / L to 1200mg / L, or from 800mg / L to 1000mg / L. Herein, diluent refers to liquid or gas, preferably gas. Suitable examples of diluents include but are not limited to carbon dioxide (CO2) and nitrogen (N2) gas.Additionally and optionally, ethylene oxide or ethylene oxide / diluent mixture may be applied at a temperature of at least 15°C, or at least 20°C, or at least 30°C, or at least 40°C, or at least 45°C, or at least 50°C. Ethylene oxide or ethylene oxide / diluent mixture may optionally be applied at a temperature of not more than 90°C, or not more than 80°C, or not more than 70°C, or not more than 60°C, or not more than 55°C. For example, ethylene oxide or ethylene oxide / diluent mixture may be applied at a temperature of from 30°C to 70°C, or from 40°C to 60°C, or from 40°C to 55°C.Additionally and optionally, ethylene oxide or the mixture may be applied at a humidity of at least 30%, or at least 40%, or at least 45%, or at least 50%, or at least 60% or at least 65%, or at least 70%, or at least 75%. It may be that the humidity is not more than 90%, or not more than 85%, or not more than 80%. For example, the ethylene oxide or the mixture may be applied at a humidity of at least 30% or at least 50%.Additionally and optionally, ethylene oxide or ethylene oxide / diluent mixture may be applied for a period of at least 1 hour, or at least 2 hours, or at least 2.5 hours, or at least 3 hours, or at least 4 hours, or at least 6 hours, or at least 7 hours, or at least 10 hours, or at least 12 hours.Optionally, the substrate and / or the copolymer (e.g. the substrate provided with the copolymer) is treated (e.g. modified) with ethylene oxide applied from an ethylene oxide / diluent mixture in which the ethylene oxide concentration is at least 300mg / L, and wherein the treatment is for a period of at least 2 hours, at a temperature of at least 40°C, and at a humidity of at least 30%.Optionally, the substrate and / or the copolymer (e.g. the substrate provided with the copolymer) is treated (e.g. modified) with ethylene oxide applied from an ethylene oxide / diluent mixture in which the ethylene oxide concentration is at least 400mg / L, and wherein the treatment is for a period of at least 2 hours, at a temperature of at least 45°C, and at a humidity of at least 30%.Optionally, the substrate and / or the copolymer (e.g. the substrate provided with the copolymer) is treated (e.g. modified) with ethylene oxide applied from an ethylene oxide / diluent mixture in which the ethylene oxide concentration is at least 800mg / L, and wherein the treatment is for a period of at least 7 hours, at a temperature of at least 45°C, and at a humidity of at least 50%.In most preferred embodiments, the substrate and / or the copolymer (e.g. the substrate provided with the copolymer) is treated (e.g. modified) by ethylene oxide applied from an ethylene oxide / diluent mixture under enhanced conditions, wherein the ethylene oxide concentration ranges from 800mg / L to 1200mg / L (e.g. 800mg / L, 1000mg / L), the temperature ranges from 40°C to 60°C (e.g., 45°C, 50°C), the humidity ranges from 50% to 90% (e.g., 50%, 75%), and the time period of modification ranges from 7 hours to 20 hours (e.g.12 hours).Any of the above-described treatments with ethylene oxide can be optionally repeated, once, or at least 2 times.Optionally, the copolymer and / or the substrate (e.g. the substrate provided with the copolymer) is treated by ethylene oxide, wherein the ethylene oxide is applied from an ethylene oxide / diluent mixture in which the ethylene oxide concentration is at least 800mg / L, optionally the temperature of treatment is at least 15°C (e.g. at least 50°C), further optionally the humidity of the treatment is at least 50%, and still further optionally the duration of the treatment is at least 7 hours. It may be that the ethylene oxide concentration is at least 100mg / L, optionally the temperature is at least 15°C or at least 40°C, further optionally the humidity is at least 40% and still further optionally the duration is at least 3 hours. It may be that the ethylene oxide concentration is at least 100mg / L, optionally the temperature is at least 15°C, further optionally the humidity is at least 30%, and still further optionally the duration is at least 1 hour. It may be that the upper limit for any of the described conditions in this paragraph is not more than 2000mg / L (for an ethylene oxide concentration), and / or not more than 90% (for humidity).It may be that the substrate comprises one or more PEGs, and optionally a plurality of single ethylene glycol units. Alternatively and additionally, it may be that the nucleobase-containing copolymer comprises one or more PEGs, and optionally a plurality of single ethylene glycol units. The ethylene glycol units (e.g. the PEGs and / or the single ethylene glycol units) may be grafted onto (e.g., anchored to) the substrate and / or copolymer. As previously discussed, it may be that the ethylene oxide treatment creates a compositional change in the nucleobase-containing copolymer, thereby improving the efficiency of DNA recovery. It may be that the substrate and / or the copolymer is modified with one or more ethylene oxide units.It may be that the nucleobase-containing copolymer per se is treated with ethylene oxide. It may be that the nucleobase-containing copolymer per se is treated with ethylene oxide such that one or more changes happen to said copolymer. For example, one or more ethylene glycol units may be provided to the nucleobase-containing copolymer. It may be that the resultant nucleobase-containing copolymer comprises one or more ethylene glycol units. The nucleobase-containing copolymer may be treated with ethylene oxide according to the treatment method described herein. The nucleobase-containing copolymer perse (i.e. the nucleobase-containing polymer prior to ethylene oxide treatment) may be as described herein. Without wishing to be bound by any theory, it is believed that the resultant copolymer improves DNA recovery in comparison to the nucleobase-containing copolymer without ethylene oxide treatment.It may be that the nucleobase-containing copolymer is treated by ethylene oxide, and then is provided to the substrate (e.g. is coated onto the substrate). It may be that the substrate is sterilised (by ethylene oxide); and the sterilised substrate is provided (e.g. coated) with the ethylene oxide treated copolymer. Alternatively or additionally, the substrate provided (e.g. coated) with the ethylene oxide treated copolymer may be treated with ethylene oxide, thereby sterilising said substrate provided with said copolymer.The present invention may provide a method of treating the apparatus by EtO, comprising: providing the nucleobase-containing copolymer; treating said copolymer with ethylene oxide as described herein; and providing the treated copolymer to a substrate, wherein optionally the substrate is sterilised, further optionally sterilised by ethylene oxide. Additionally and optionally, after providing the treated copolymer to the substrate, this method comprises treating the substrate provided with the copolymerwith ethylene oxide, thereby sterilising said substrate provided with said copolymer. Optionally, this method is used in connection with the previously described method of making the apparatus (e.g. method steps [i] -[iv]).In the context of the present invention, it may be that the volume of the aqueous sample is from 5mL to 100mL, or from 10 mL to 50 ml_, or from 10mL to 25mL. Alternatively, it may be that the volume of the aqueous sample is from 200 mL to 5L, or from 500mL to 3L, or from 500mL to 1L (e.g. a single void of urine or multiple voids of urine). The apparatus may be a flow-through apparatus, configured to allow an unlimited volume of input (e.g. sample) to pass through. The apparatus may be a fluidic apparatus.The nucleic acid comprised in the aqueous sample is preferably a cfDNA, more preferably a ctDNA (circulating tumour DNA). It may be that the cfDNAs are selected from nucleosome-bound cfDNAs, exosome-bound cfDNAs, unbound cfDNAs and mixtures thereof. It may be that the nucleic acids are selected from single-stranded DNAs, single-stranded RNAs, double -stranded DNAs, double-stranded RNAs, and mixtures thereof.It may be that the nucleic acid is a DNA (e.g. cfDNA). It may be that the DNA originates from living organisms, injured or dead organisms, laboratory cell or tissue lysis, waste, microorganism infections, or invasive species. Capturing and analysing this DNA can be used in fields such as health applications, aquaculture, forensics, biosurveillance, brewing, fermentation, bioreactors, and wastewater management.It may be that the nucleic acid does not include encapsulated or cellular sources of DNA (e.g. cellular DNA). Cellular DNA may refer to DNA that exists naturally within the cells of an organism. Cellular DNA may include nuclear DNA, mitochondrial DNA, and / or plasmid DNA. Encapsulated DNA may refer to DNA that is enclosed within a protective structure, such as viral capsid or a delivery vehicle like nanoparticles or liposomes. The encapsulation may be natural (e.g. as in viruses) or engineered (e.g. as in gene applications).Nucleic acids (e.g. cfDNAs) may also be selected from double-stranded DNAs, singlestranded DNAs, oligonucleotides, and mixtures thereof. A single-stranded nucleic acid, such as a single-stranded DNA (e.g. ss cfDNA), may comprise from 20 bases to 500 bases, typically from 50 bases to 400 bases, more typically from 100 bases to 300 bases. It is also possible for a single-stranded nucleic acid such as a single-strandedDNA (e.g. ss cfDNA) to comprise large fragments, for example, from 1 kilobases (kb) to 1000 kb, typically from 10 kb to 800 kb, more typically from 50 kb to 700 kb, still more typically from 100 kb to 500 kb. A suitable example of a single-stranded DNA (e.g. ss cfDNA) comprises 160 bases. A double-stranded nucleic acid, such as a doublestranded DNA (e.g. ds cfDNA), may comprise from 50 base pair (bp) to 500 bp, typically from 100 bp to 400 bp, more typically from 200 bp to 300 bp. It is also possible for a double-stranded nucleic acid such as a double-stranded DNA (e.g. ds cfDNA) to comprise large fragments, for example, from 1 kilo base pair (kbp) to 1000 kbp, typically from 10 kbp to 800 kbp, more typically from 50 kbp to 700 kbp, still more typically from 100 kbp to 500 kbp. A suitable example of a double-stranded DNA (e.g. ds cfDNA) comprises 160 bp.It may be that the concentration of the nucleic acid (e.g. cfDNA) in the sample is from 0.1ng / mL to 100ng / mL, or from 1 ng / mL to 100ng / mL, or from 2ng / mL to 70ng / mL, or from 5ng / mL to 50ng / mL. In a suitable example, the concentration of the nucleic acid (e.g. cfDNA) is 10 ng / mL. Herein, the concentrations refer to the original nucleic acid concentrations in the samples (prior to any capture by the apparatus). Typically, the apparatus can capture 10% to 90% nucleic acid comprised in the aqueous sample (e.g. for a 10ml_ sample comprising 100ng nucleic acid in total, the apparatus can capture from 10 ng to 90ng nucleic acid.), more typically from 30% to 85%, still more typically from 50 to 80%. Typically, the density of the captured nucleic acids on the substrate is from 0.1ng / cm3to 100ng / cm3, more typically from 0.5ng / cm3to 50ng / cm3, still more typically from 1 ng / cm3to 20ng / cm3, most typically from 3ng / cm3to 10ng / cm3. It may be that the density is at least 5ng / cm3, or at least 20ng / cm3, or at least 30ng / cm3, or at least 50ng / cm3, or at least 60ng / cm3. Optionally, it may be that the density is not more than 100ng / cm3, or not more than 80ng / cm3, or not more than 70ng / cm3. Typically, the nucleic acid recovery per 1cm2surface area of the substrate is from 0.1 ng to 50ng, or from 0.2ng to 30ng, or from 1ng to 20ng, or from 1ng to 10ng, or from 1ng to 5ng. It may be that the nucleic acid recovery per 1cm2surface area of the substrate is at least 5ng, or at least 20ng, or at least 30ng, or at least 50ng, or at least 60ng. Optionally, it may be that the nucleic acid recovery per 1 cm2surface area of the substate is not more than 100ng, or not more than 80ng, or not more than 70ng. Typically, the recovery rate of the apparatus is from 5% to 90% (e.g. for a 10mL sample comprising 100ng nucleic acid in total, the apparatus can recover 5ng to 90 ng nucleic acid), more typically from 10% to 80%, still more typically from 15% to 70%. Typically, the apparatus can recover from 1ng to 5000ng nucleic acids, or from 1ng to 2000ng nucleic acids, or from 5ng to1000ng nucleic acids, or from 10ng to 950ng, or from 100ng to 900ng, or from 500ng to 900ng.The above-described capture and recovery of nucleic acids can be achieved by a single or double uses of the apparatus. The apparatus may be configured to use one or more times (i.e. single use or multiple uses) to capture nucleic acids from the same or different aqueous samples.The present invention may provide the apparatus, as described herein. The apparatus may comprise a substrate which is different from the nucleobase-containing copolymer. Said substrate is provided with said copolymer. Alternatively, the apparatus may comprise a substrate which is (formed of) the nucleobase-containing copolymer.The substrate (different from said copolymer) may be a matrix, typically a porous matrix. The pore size of the substrate may be from 50pm to 2000pm, typically from 100pm to 1500pm, more typically from 200pm to 1000pm. The pore density (pore per inch / ppi) of the substrate may be from 15ppi to 100ppi, or from 20ppi to 95ppi, or from 40ppi to 90ppi, or from 50ppi to 90ppi. The substrate may comprise a plurality of openings. The porosity may provide high surface area, allowing for large volumes (e.g. unlimited volumes) of the aqueous sample to pass through the substrate.It may be that the substrate is selected from meshes, sponges, beads, and fibres. Typically, the substrate is a sponge (e.g. a polyurethane sponge). If may be that the substrate is in the form of a plurality of beads. Herein, beads refer to particles that are spherical or irregular in nature. The size of beads optionally ranges from 0.1pm to 1mm in diameter, or from 1 pm to 100pm, or from 2pm to 50pm, or from 5pm to 10pm. The nucleobase-containing copolymer may be coated on the meshes, sponges, beads, or fibres.Typically, the substrate permits liquid (e.g. aqueous sample) to pass through. Typically, the substrate permits at least some of the non-nucleic acid components from the sample to pass through while capturing nucleic acids. Typically, the substrate permits release of the captured nucleic acids for subsequent analysis. Typically, the substrate comprises a surface, and the nucleobase-containing copolymer is provided on said surface. During use, the nucleic acids from the sample can bind onto said surface.It may be that the specific surface area of the substrate is at least 10cm2 / cm3, or at least 15cm2 / cm3, or at least 20cm2 / cm3, or at least 25cm2 / cm3, or at least 35cm2 / cm3. Optionally, the specific surface area is not more than 60cm2 / cm3, or not more than 50cm2 / cm3, or not more than 45cm2 / cm3. The specific surface area may be from 20cm2 / cm3to 50cm2 / cm3, or from 35cm2 / cm3to 45cm2 / cm3. It may be that at least part of the substrate or preferably the whole substrate has the specific surface area as described herein. It may be that the specific surface area (SSA) refers to SSA of the substrate which is not the nucleobase-containing copolymer and without provision of said copolymer (i.e. the original, naked substrate). It may be that the specific surface area refers to SSA of the substrate which is the nucleobase-containing copolymer or coated with the nucleobase-containing copolymer. The specific surface area can be determined in accordance with established methods. For example, ASTM F2450-18. Nitrogen absorption-based isotherms (NAI) or mercury intrusion porosimetry (MIP) may be used.It may be that the specific surface area is measured and calculated as set out below. A section of the substrate is imaged under magnification in reference to a known, calibrating distance, using a calibration microscope slide or graticule. The acquired digital image is uploaded into a suitable image analysis software (e.g. ImageJ / FIJI) and the calibrating distance is used to set the correct scale. After this, the diameter of the substrate filaments (e.g. solid polyurethane struts formed around the pores and openings) can be measured and a mean diameter (d) or radius (r) can be calculated. The specific surface area (cm2 / cm3) can be calculated for a given volume of substrate provided the density of the material (e.g. polyurethane) and the mass of the required volume are known. mass of substrate i , <• , / density of polyurethane =volume°f P^r ethaneThe filaments of the substrate have been observed to be cylindrical, thus it can be assumed that the entire volume of the material (e.g. polyurethane) follows the calculation for the volume of a cylinder and the subsequent rearrangement: volume of polyurethane = nr2x L, > volume of polyurethane / — i nr2With a known length (L) of cylindrical filament equating to all the material (e.g. polyurethane) within a given substrate volume, the surface area of a hypothetical single, long cylinder can be calculated, providing the total surface area of the material (e.g. polyurethane) within the substrate: surface area of filament = 2nrL + 2nr2surface area of filament specific surface area = - - - - - - - - - volume of polyurethaneThe method specified herein can be referred to as an ‘Imaging Method’. It will be understood that other methods of measuring specific surface area are widely known and may be suitable. The methods (e.g. ’Imaging Method’) may be applicable to materials in general including polyurethane materials. The methods (e.g. ‘Imaging Method’) may also be used to determine the volume and / or the total surface area of the substrate.It may be that the increase of SSA leads to further improvement of efficiency with respect to nucleic acid capture and / or recovery. The identified ranges as described herein are particularly preferred. However, without wishing to be bound by any theory, it is believed that if the specific surface area is too high (i.e., the substrate is too dense), it is possible that part of the aqueous sample will not travel through but merely travel around the substrate. In other words, the capture and / or recovery of nucleic acids may reach a maximum (and possibly plateau with further increase of the SSA).The total surface area of the substrate may be at least 10cm2, or at least 20cm2, or at least 40cm2, or at least 100cm2, or at least 500cm2, or at least 800cm2, or at least 1500cm2. The surface area of the substrate may optionally be no more than 8000cm2, or no more than 6000cm2, or no more than 5000cm2, or no more than 4000cm2, or no more than 3600cm2. The identified total surface area may optimise the efficacy of the nucleic acid recovery. The total surface area may be defined by the volume and the specific surface area (e.g. see above, the ‘imaging method’ wherein the total surface area = volume x specific surface area). The total surface area may refer to the total surface area of the substrate which is not the nucleobase-containing copolymer and without provision of the copolymer (i.e. the original, naked substrate). The total surface area may refer to the total surface area of the substrate which is the nucleobase- containing copolymer.When the substrate is provided with a nucleobase-containing copolymer, the copolymer may be chemically and / or physically attached to the substrate. The chemical attachment may be i / / a one or more chemical interactions. Said interactions may be covalent, and / or ionic, and / or via electrostatic interactions, and / or hydrogen bonding. The physical attachment may be a physical adsorption and / or hydrophobic effect or entrapment. The copolymer may be adsorbed onto the substrate. The polymer may be provided on the substrate (e.g. coated on the substrate) in the form of one or more layers. The layered morphology of the polymer may lead to improved nucleic acid capture and / or recovery.It may be that at least 70% of the surface area of the substrate is provided with (e.g. coated with) the copolymer. In other words, the copolymer covers at least 70% of the surface area of the substrate. Optionally, the copolymer covers at least 80%, or at least 90% or at least 95% or 100% of the surface area of the substrate.The copolymer morphology and / or the copolymer coverage described herein may be determined by any known and effective methods. For example, the substrate provided with the copolymer may be viewed by scanning electron microscopy (SEM) or any suitable microscopy techniques. Images (e.g. in-depth images) may be obtained, and topographical analysis and / or calculations may be performed to analytically determine the copolymer coverage.The apparatus of the invention can be a fluid collecting apparatus (e.g. a fluid collector). The apparatus can be a fluidic apparatus, for example, a flow cell. Suitably, the apparatus is an extracorporeal apparatus.The apparatus is configured to capture the nucleic acid from the aqueous sample, wherein said sample is selected from environmental water samples, industrial water samples, wastewater samples, and excretory fluid samples (e.g. urine samples).The apparatus comprises the substrate which is the copolymer or is provided with said copolymer.It may be that the apparatus further comprises a device for handling water, optionally selected from water pumps, nets, syringes, cartridges, vessels, rods, filters, funnels, and fluid collectors. The device may be configured to process or treat water (e.g. filters,water pumps, cartridges, syringes). The device may be configured to filter, regulate, transfer, and / or sample water.It may be that the substrate is connectable or connected to the device (e.g. the substrate is operatively connected to the device). It may be that the substrate is (operatively) in fluid communication with the device. Herein, fluid refers to gas or liquid. The device may be provided with, connected to, or otherwise in fluid communication with the substrate.It may be that the device is a fluid collector. It may be that the apparatus comprises the fluid collector, and the substrate is received or receivable in said collector. It may be that the fluid collector comprises (e.g. is) a collection pot (e.g., a urine collection pot), or any container suitable for collecting the aqueous sample as well as receiving the substrate. The collector may comprise an inlet (e.g. an opening) for receiving the aqueous sample into the collector. The substrate may be the copolymer or be provided with said copolymer. The apparatus may be a static apparatus, without a passageway for the aqueous sample to pass through the apparatus. The collector may be configured to allow the incubation of nucleic acids with the substrate within said collector. The collector may be configured to permit the removal of the substrate, for instance, via the inlet such as the opening. The removed substrate may be processed for bound nucleic acids.The apparatus may be configured to allow the aqueous sample (e.g. urine) to pass through it. It may be that the device is a cartridge. It may be that the apparatus comprises the cartridge comprising an inlet, an outlet and a passageway connecting the inlet and the outlet. The passageway may be an internal passageway within the cartridge. It may be that the substrate is receivable or received (e.g. contained) within the passageway. It may be that the apparatus is configured to allow the aqueous sample to be introduced into the cartridge through the inlet, pass through the substrate and exit through the outlet such that when the sample passes through the substrate, the copolymer captures the nucleic acid from the sample.It may be that the apparatus comprises one or more flow-control components (e.g. funnels), optionally retained or retainable within the cartridge. Said component(s) may be connected or connectable to the substrate. Typically, one component (e.g. funnel) is configured to be positioned upstream of the substrate, and optionally one further component (e.g. funnel) is configured to be positioned downstream of the substrate. Itmay be that the said one component and / or the said one further component are operatively in fluid communication with the substrate. It may be that the apparatus comprises two flow-control components. The flow-control components help direct flow of the aqueous sample through the substrate, improving contact between the nucleic acids in the aqueous sample and the copolymer.It may be that the cartridge’s inlet is connected or connectable with an input path (e.g. an input tube). Said input path may be configured to receive the aqueous sample and direct it into the cartridge via the input. It may be that the cartridge’s outlet is connected or connectable with an output path (e.g. an output tube). Said output path may be configured to guide or control the flow of the aqueous sample once it has exited the output. It may be that the apparatus comprises the input path and / or the output path.The apparatus may be designed to allow recirculation of the aqueous sample, optionally through the substrate and / or the water handling device such as the cartridge. It may be that the apparatus comprises a recirculation mechanism (e.g. a re-circulator), configured to recirculate the aqueous sample through the device (e.g. cartridge) from the outlet back to the inlet. It may be that said mechanism is configured to recirculate the aqueous sample from the output path (e.g. the output tube) back to the input path (e.g. the input tube). It may be that the recirculation mechanism is configured to act on the input tube and / or the output tube, to enable recirculation. It may be that the recirculation mechanism is designed to control the flow rate (through the substrate and / or the device), optionally from 1 mL / min to 100mL / min, or from 5mL / min to 50mL / min, or from 10mL / min to 25mL / min, or at 20mL / min. It may be that the recirculation mechanism is a pump such as a peristaltic pump.The substrate may be the copolymer or be provided with said copolymer. It may be that the cartridge provides a housing or chamber or a column for receiving the substrate. The cartridge may be configured to promote directional flow of the aqueous sample through the apparatus. The cartridge may be rigid (e.g. optionally made of plastic or metal). The inlet may be configured to allow the subject (e.g. the patient) to urinate directly into the cartridge. The passageway may be configured to allow the urine to flow through. The outlet may be configured to allow the urine to exit. The apparatus (e.g. the cartridge) may be configured to allow the subject to urinate through it.Alternatively or additionally, the apparatus may comprise a separate vessel for collecting the aqueous sample (e.g. urine). The inlet may be configured to allow theinput of the aqueous sample from said separate vessel into the cartridge, and / or the said vessel may be configured to allow the input of the aqueous sample into the cartridge via the inlet. The said vessel may be attached or attachable (e.g. removably attached) to the substrate or the cartridge (e.g. the inlet of the cartridge). It may be that the said vessel is configured to allow the subject (e.g. the patient) to urinate into it. The said vessel may optionally comprise an outlet (at its bottom), allowing the aqueous sample (e.g. urine) to pass through (to the cartridge or to the substrate).It may be that the apparatus comprises a handling portion (e.g. a handle), optionally attached or attachable to the said vessel. Said handling portion may be configured for the subject (e.g. patient) to hold the vessel (when urinates into the vessel). It may be that the apparatus comprises an engagement member configured to engage with a facility (e.g. a toilet rim). It may be that the vessel or the handling portion is provided with the engagement member. It may be that the engagement member is configured to allow the vessel to be (removably) secured to the facility (when the patient urinates into the vessel). The engagement member may be a clip.The cartridge may be configured to allow the incubation of nucleic acids with the substrate within said cartridge. The cartridge may be removable from the apparatus. The cartridge may be configured to permit the removal of the substrate, for instance, via the inlet or the outlet. The removed substrate may be processed for bound nucleic acids.The apparatus can be of varying sizes and dimensions, scaled appropriately to accommodate the volume of the aqueous sample. It may be that the water handling device (e.g. the collector, the cartridge) is configured to contain the substrate. For a static apparatus, the apparatus may be configured to collect the aqueous sample of a pre-determined volume, such as an entire void of urine or multiple voids. The fluid collector in such an apparatus may range in volume from 10mL to 2L, or from 50mL to 1L, or from 100mL to 500mL. Alternatively, the apparatus may be configured to allow passage of unlimited volumes of the aqueous sample. In this case, the cartridge in such an apparatus may range in volume from 10mL to 200mL, or from 20mL to 100ml_, or from 40mL to 60mL.It may be that the apparatus comprises a cover (e.g. a removable cover), designed to fully or partially block the outlet of the cartridge. The cover may serve as an outlet control component, which may take the form of a cap, plug, lid, stopper, valve, seal,filter, blocker, or the like. It may be that the cover is configured for selective containment or release of the aqueous sample from the cartridge. It may be that the cover is connected or connectable to the outlet. It may be that the cover is disposed within or outside the cartridge. The cover may be a lid. The apparatus may optionally comprise a lid (to prevent the spillage of the aqueous sample). In this manner, the cover can be used to block (e.g. seal) the outlet after sample collection, allowing the sealed sample to be sent via postage for further processing and / or analysis.The apparatus may further comprise a receptacle (e.g. a sealable plastic bag), wherein the water handling device and / or the substrate is received or receivable within said receptacle. The apparatus may further comprise one or more printed or written labels. The labels may contain the sample (e.g. urine sample) and / or the subject (e.g. the patient) information. The labels may also be in any medium capable of storing the information and communicating it to the user of the apparatus.It is found that the copolymer binds the nucleic acid from the aqueous sample in operation. The copolymer-bound nucleic acid (e.g. copolymer-nucleic acid complex) is generally stable under ambient conditions (e.g. 20-25°C, 1atm). ‘Stable’ should be understood to mean the captured nucleic acid or the complex does not undergo any compositional, chemical, or physical changes. It may be that the captured nucleic acid or the complex remains stable for at least 1 week after sampling, or at least 1 month, or at least 3 months. This stability allows for flexibility in the use of the apparatus, as it can be utilized in various settings such as point-of-care, low-resource environments, and even at home. By way of example, the DNA can be collected from a urine sample at one location (e.g. home), then sealed and transported to a processing laboratory where it can be washed and eluted from the apparatus. While this example is about DNA collection from a urine sample, this flexibility extends beyond urine samples to other aqueous samples like cultivation water samples or wastewater samples.It may be that the apparatus further comprises a size-exclusion filter positioned upstream of the substrate. The size-exclusion filter may be configured to allow water to flow through. Said filter may comprise one or more of: a mesh, a strainer, a sponge, a foam, and a screen. The substrate may be the copolymer or be provided with the copolymer. In operation, the aqueous sample flows through the size-exclusion filter before reaching the substrate, wherein the nucleic acid in the sample is captured by the copolymer. The size-exclusion filter may be operatively in fluid communication with the substrate. The size-exclusion filter may be configured to remove solids, such assolid particles, from the aqueous sample. Specifically, said filter may be configured to filter out debris, soil, algae, and / or dead or live animals. This pre-filtration process prevents soiling of the substrate. The inclusion of the size-exclusion filter helps to protect and extend the lifespan of the substrate by preventing clogging with large particles or debris. Consequently, this improves the efficiency and longevity of the apparatus.The apparatus may be configured for transient use in sampling. Specifically, the apparatus may be configured for instant immersion in water, such as a single dip into the water, or for water to flow through the apparatus. The apparatus may be configured to collect an aqueous sample from the aqueous environment (sample reservoir), optionally for a short duration, ranging from approximately 10 minutes to 20 hours, or for an extended duration, ranging from approximately 1 day to 1 or 2 months. The apparatus may be configured to collect samples from environmental water (e.g. cultivation water, aquaculture water), industrial water, wastewater, or excretory fluid (e.g. urine).The apparatus may be configured to adjust one or more parameters such as temperature, volume, pressure, and fluidic speed of the sample. The apparatus may comprise one or more controllers to adjust those parameters (e.g. a temperature controller). The apparatus may comprise a temperature sensor, or a pressure sensor, or a speed sensor, or a volume sensor, or combinations thereof. Said sensors may be optionally incorporated into said controllers. For example, the temperature sensor may be incorporated into the temperature controller.Further, the apparatus may be provided as a product wherein said apparatus is contained within a packaging, and the product preferably comprises instructions for use. It may be that the packaging comprises a primary packaging within which the apparatus is contained, and a secondary packaging within which the primary packaging is contained. Suitably, at least one of the packaging described above can protect the apparatus from light (e.g., direct sunlight), moisture, physical and / or chemical damages and contaminants. The instructions may give detailed information for the steps of using the apparatus in accordance with the method of capturing the nucleic acid, as described herein. The instructions may be supplied in the printed or written form of a label, a booklet, a brochure, a scannable code (e.g. a barcode), or a leaflet. The instructions may also be printed or written on at least one packaging of the product.The invention provides the method of capturing nucleic acid from the aqueous sample by using the apparatus comprising the substrate which is the nucleobase-containing copolymer or is provided with said copolymer. The method, the nucleic acid, the aqueous sample, the apparatus, the substrate, and the copolymer may be as described herein.The method may be optionally repeated (e.g. once or twice) to further increase the nucleic acids supply for further analysis. It may be that for a single operation, the method can capture from 10% to 90% nucleic acids contained in the sample, or from 30% to 85%, or from 50% to 80%, and optionally the recovery rate of the nucleic acids is from 5 % to 90%, or from 10% to 80%, or from 15% to 70%, or from 50% to 70%.The method may comprise incubating the aqueous sample (e.g. the nucleic acid) and the copolymer (e.g. the substrate provided with the polymer), optionally at a temperature of at least 4°C, or at least 20°C, or at least 30°C, but not more than 40°C. A suitable example of the temperature is about 37°C (i.e. , equivalent to human body temperature). It may be that the incubation period is at least 10 seconds, or at least 20 seconds, or at least 1 minute. It may be that the incubation period is not more than 2 hours, or not more than 1 hour, or not more than 50 minutes, or not more than 40 minutes. It is also possible that the incubation period is at least 1 hour or at least 3 hours, or at least 6 hours, or at least 12 hours. Optionally, the incubation period may be not more than 7 days, or not more than 2 days, or not more than 24 hours. Typically, the aqueous sample operably flows over the copolymer, optionally at a flow rate of at least 20mL / minute, more typically at least 3 mL / minute. Optionally, the flow rate is not more than lOOmL / minute, or not more than 80ml_ / minute, or not more than 70mL / minute. Typically, the aqueous sample (e.g. the nucleic acid) and the copolymer (e.g., the substrate provided with the copolymer) are incubated in an incubation composition. The composition may be a solution. The composition may be an excretory fluid (e.g. urine). The composition may or may not be diluted.The method may further comprise one or more of the following steps of: a. separating the nucleic acids from the aqueous sample optionally without the use of centrifugation or pre-filtration; b. washing a copolymer-nucleic acid complex to remove one or more other components from the sample; c. releasing some of or all of the nucleic acids from the copolymer; d. characterising the nucleic acids; e. sequencing the nucleic acids; and f. identifying a disease state based on the characterisation of the nucleic acids.As discussed, the nucleic acid (e.g.DNA) may be captured (e.g. collected) from the aqueous sample at one location (e.g. home), then sealed and transported to a different location (e.g. a laboratory) for processing. Therefore, the method may also comprise sealing and transporting the captured nucleic acid to a location which is different from the location where the nucleic acid has been captured (by the copolymer in the apparatus). The method may comprise washing the copolymer-nucleic acid complex to remove one or more other components from the sample in said different location. The method may comprise any of the steps c, d, e, and f, performed in said different location or in a further different location.Typically, the copolymer-nucleic acid complex is washed by a saline. Typically, the saline has a neutral pH (i.e. pH from 6 to 8). A suitable example of the saline is phosphate-buffered saline (PBS).Typically, at least some of if not all of the nucleic acids are released from the copolymer with an elution buffer. Typically, the elution buffer has an ionic strength equivalent to or higher than that of 600mM sodium chloride solution. The elution buffer may have a pH from 4 to 10, typically from 5 to 9, more typically from 6 to 9, most typically from 8 to 9. It is found that the elution buffer with high ionic strength and / or alkaline pH leads to high efficiency of nucleic acid recovery. The recovered nucleic acid can then be used for subsequent analysis, with or without purification. The above-described eluting procedure can be optionally repeated to afford more nucleic acids, preferably repeated once or twice.Typically, characterisation of the nucleic acids may include one or more activities of: determining a concentration, a quality metric, a physical mapping, a sequence content, an epigenetic information, SNP, a haplotype, an RFLP, sizing, and a copy number variant.Typically, sequencing the nucleic acids may be via Next Generation Sequencing. The captured nucleic acids may be used in one or more PCR methods. It may be that the captured nucleic acids are used for sequencing and / or one or more PCR methods.Identification of sample states may involve purification and optionally identification or quantification of nucleic acids, preferably cfDNA. Suitably the identification may comprise labelling polynucleotides of cfDNA to identify or quantify the cfDNA. Afluorophore, a quantum dot, a dendrimer, a nanowire, a bead, a hapten, a streptavidin, an avidin, a neutravidin, a biotin, and a reactive group a peptide, a protein, a magnetic bead, a radiolabel, or a non-optical label may be applied to the nucleic acids. In some embodiments, a label can be a fluorophore or a quantum dot.The present invention may provide a method of making the apparatus as described herein. The method may comprise: (i) making the nucleobase-containing copolymer preferably by RAFT polymerisation, optionally treating the copolymer with ethylene oxide; (ii) optionally dissolving the copolymer into a solvent; (iii) treating the substrate with the copolymer, optionally the dissolved copolymer; and optionally (iv) treating the substrate provided with the polymer obtained in step (iii) with ethylene oxide. The solvent, the copolymer concentration and the ethylene oxide treatment may be as described herein. The substrate provided in step (iii) may be a sterilised substrate, optionally sterilised by ethylene oxide.The present invention will now be illustrated with reference to the following non-limiting Examples.Figures 1(a) - (k): show the monomer feedstock of synthesized copolymers according to embodiments of the present invention; andFigure 2: shows the DNA recovery after ethylene oxide treatment, according to embodiments of the present invention.The copolymers used were typically synthesised on a 1g scale. Monomers were passed through basic alumina columns to remove inhibitors. These purified monomers were combined in the presence of a chain transfer agent (2-Cyano-2-propyl dodecyl trithiocarbonate) and initiator (2,2'-Azobis(2-methylpropionitrile)) at a typical ratio of 1000:5:1 , or 1500:5: 1 in a microwave vial and dissolved in DMSO to a final reaction concentration of 5 molar. The reactions were degassed with N2 for 30 minutes. Polymerisations were stirred at 60°C under N2 for about 24 hours, or up to 7 days. The reactions were stopped by cooling with dry ice and acetone and exposed to air. The copolymers were purified by precipitation first into water, then three times by dissolvingin ethyl acetate and precipitated in hexane. The copolymers were then dried of solvent in a vacuum oven (40°C).1H-NMR was used to measure the composition of the obtained copolymers. The results are as provided in Table 1 hereinbefore. In detail, ‘H-NMR Method’ can be used. The characterisation was undertaken using a process wherein 5 mg of dried copolymer was dissolved in 600 pL DMSO-d6 and submitted for compositional analysis using1H-NMR, recorded using a Bruker AVA-500 at 500MHz and 298K. The broad peak corresponding to 2H (3.80-4.30 ppm) on the carbon beta to the carboxylate on copolymer side chains was set to represent 100% of the monomer components. This peak was shared by all monomers incorporated in the polymer. Individual monomer components were identified in reference to pure monomer samples, integrated, and calculated as a proportion of all monomer components.The copolymers are as described in Table 1 : DEAEA50-X, DEAEA50-26, ThEA5-X, DEAEA-X-BLOCK, BRANCHED-X-DP300, BRANCHED-X-DP50, CyEA1-X-SWAP, CyEA5-X, TyCy1-X, APMAA10-X-SWAP, APMAA30-X-SWAP, HEMA10-X, PhEMA10-X, MA-H10-X, HEMA-X-SWAP, and MEMA-X-SWAP.Figure 1 (a) - Figure 1(k) show the monomer feedstock of these synthesized copolymers.Fig.1(a): 2-methyoxy-ethyl methacrylate (MEMA)Fig.1(b): 2-(diethyl-amino)ethyl acrylate (DEAEA)Fig.1(c): 2-methoxy-ethyl acrylate (MEA)Fig.1(d): thymine ethyl acrylate (ThEA)Fig.1(e): polyethylene glycol monomethyl ether acrylate (PEGA)Fig.1(f): cytosine ethyl acrylate (CyEA)Fig.1(g): N-(3-amino-propyl)methacryl amide hydrochloride (APMAA)Fig.1(h): 2-hydroxyethyl methacrylate (HE A)Fig.1 (i): 2-phenoxy-ethyl methacrylate (PhEMA)Fig. 1(j): methacrylic acid (MA-H)Fig. 1 (k): ethylene glycol dimethacrylate (EGDMA)Example 2 - DNA recovery from urineThe following samples were tested for DNA recovery. Sample 1 was a substrate coated with poly(2-methoxy-ethyl methacrylate) [polyMEMA], Sample 2 was a substrate treated with coating solvent only (SolventCT). Sample 3 was a substrate without any treatment (Fresh). Samples 4-17 were substrates coated with some of the copolymers of Table 1. These samples were screened for DNA recovery from artificial urine (recipe from Sarigul et al,

[2019] , Sci Rep., 9, 20159) spiked with DNA in an ex- vivo setting. Polyurethane sponges (2.5cm3) were used as substrates. Three replica sponges (n=3) were tested for each sample. Each sponge was incubated in 1mL DNA-spiked urine for 1 hour. The sponges were then removed from the spiked urine and washed with PBS before elution of the bound DNA using an elution buffer consisting of 0.1 M Tris- HCI, pH 8.5, 1.25M NaCI (E4 Buffer, Invitrogen™). Once purified, the DNA was quantified fluorometrically to reveal the performance of each sample.Table 2 DNA recovery(ng) from artificial urineThe results in Table 2 show that the polyurethane sponges coated with the copolymers of Table 1 recovered more DNA than the untreated sponges, solvent-treated sponges and pMEMA-treated sponges. Through statistical testing (one-way ANOVA, Tukeypost-test), three copolymers (TyCy1-X, DEAEA-X-BLOCK, APMAA10-X-SWAP) were identified as having performed the best.In a separate experiment involving 10mL of unspiked donor urine, fragment size analysis revealed that both TyCy1-X and APMAA10-X-SWAP showed a higher enrichment of smaller DNA fragments (i.e.50 to 700 base pairs), a characteristic typical of cell-free DNA (cfDNA).oxide (EtO) treatmentIn this example, polyurethane sponges (7.5 cm3) were coated with TyCy1-X, DEAEA- X-BLOCK, and APMAA10-X-SWAP. These coated sponges were treated with 800- 810mg / L ethylene oxide at 45-53.5°C for 720 minutes under a humidity level of at least 50%. This treatment was compliant with ISO 11135-1 :2007 for EtO sterilization of healthcare products. Unspiked donor urine (10 mL) was recirculated with the treated sponges for 1 hour. DNA was then recovered using a method similar to that described in Example 2. Three replicates (n=3) were tested for each copolymer.A commonly used DNA extraction kit (Qiagen QIAamp Circulating Nucleic Acid Kit), hereinafter referred to as ‘Standard Kit A’, was used as a control example. Since Standard Kit A is not indicated for processing 10 mL of liquid, the urine sample was split into two 5 mL extractions, which were then pooled.Figure 2 shows the results of the DNA recovery. The DNA recovery was significantly enhanced using these copolymers treated with ethylene oxide, with up to 9-fold more DNA recovered per 1 mL input compared to Standard Kit A. As previously observed, there was also some enrichment for 50-700 bp DNA using the copolymers compared to the comparator. It is noted that the exact proportion of cfDNA present in a sample is highly variable due to the heterogeneity of urine between donors and across different collection times; therefore, the values of cfDNA proportions listed in Figure 2 may not be directly comparable across different urine experiments.As the copolymer approach does not have a volume input limit, even greater DNA recovery can be achieved by processing larger aqueous samples.Example 4 - DNA recovery without ethylene oxide (EtO) treatmentIn this example, polyurethane sponges (80 cm3) were coated with TyCy1-X, DEAEA- X-BLOCK, and APMAA10-X-SWAP. These coated sponges were not treated with ethylene oxide. Male donor urine (170 ml_) was recirculated with the coated sponges for 60 minutes at 20 mL / min. DNA was then recovered using a method similar to that described in Example 2. Specifically, the samples were washed with 300ml_ PBS, followed by a 10-minute elution. 60mL elution buffer was used for each sample. The sample was incubated in the said elution buffer for 10 minutes. To improve contact between the buffer and the sponge and to help control the overall elution volume, the buffer was drawn in and out of the sponge 3 times at the beginning of the 10-minute period, 3 times at the midpoint (5-minute time point), and 3 times at the end of the 10- minute period. Alternatively, the elution step may be carried out via a 10-minute recirculation. The recovered DNA was purified and quantified fluorometrically. One sample (n=1) was tested for each copolymer. The ‘Standard Kit A’ was used as a control sample.Figures 3 and 4 show the quantities of the DNA recovery (ng) and the percentages of 50-700bp DNA recovery (%), respectively. The DNA recovery was significantly improved using the copolymer-coated sponges, compared to Standard Kit A. This included an increased proportion of DNA sized 50-700 bp. The captured DNA was analysed using the High Sensitivity D1000 ScreenTape Assay (TapeStation HSD1000), and the results are shown in Figure 5. In Figure 5, lines 1-4 correspond to results from DEAEA-X-BLOCK, TyCy1-X, APMAA10-X-SWAP, and Standard Kit A, respectively. The sample intensity for 50-700bp DNA was markedly higher in all three copolymer-coated samples compared to the control Standard Kit A. It demonstrates that these copolymer-coated sponges enhanced DNA recovery with significantly more proportion of 50-700bp DNA, relative to the control sample.Again, as the copolymer approach does not have a volume input limit, even greater DNA recovery can be achieved by processing larger aqueous samples.

Claims

Claims1 A method of capturing nucleic acids from an aqueous sample, comprising: providing an apparatus configured to capture the nucleic acids from the aqueous sample, wherein the apparatus comprises a substrate which is a copolymer or is provided with said copolymer, the copolymer comprising nucleobase-containing moieties, positively charged moieties at pH from 2 to 11 adapted to bind the nucleic acids via electrostatic interaction, and uncharged moieties, and wherein the aqueous sample is selected from environmental water samples, industrial water samples, wastewater samples, and excretory fluid samples; contacting the aqueous sample comprising the nucleic acids with the nucleobase-containing copolymer comprised in the apparatus; and allowing the nucleic acids to bind to the nucleobase-containing copolymer thereby capturing said nucleic acids by said copolymer.2 The method according to claim 1 , wherein the molar proportion of the uncharged moieties is at least 4 times that of the positively charged moieties.3 The method according to claim 1 or claim 2, wherein the logarithm of partition coefficient (LogA) of the copolymer is less than 0.83, or less than 0.4 The method according to any one of the preceding claims, wherein the copolymer comprises: (i) (meth)acrylate-based monomers with nucleobase side chains, providing the nucleobase-containing moieties, (ii) (meth)acrylate- based monomers with amine side chains, providing the positively charged moieties, and (iii) uncharged, (meth)acrylate-based monomers providing the uncharged moieties.5 The method according to claim 4, wherein the monomers (i) are selected from thymine ethyl acrylate (ThEA), thymine acetoxyethyl methacrylate (ThAcMA), cytosine ethyl acrylate (CyEA), and mixtures thereof,6 The method according to claim 4 or claim 5, wherein the monomers (ii) are selected from diethylamino ethylacrylate (DEAEA), diethylamino ethyl methacrylate (DEAEMA), N-(3-aminopropyl)methacrylamide hydrochloride (APMAA), N-(3-aminopropyl)acrylamide hydrochloride (APAA), 3-(dimethyl-amino)propyl acrylate (DMAPA), N,N-diethyl acrylamide (DEAA), and mixtures thereof.7 The method according to any one of claims 4 to 6, wherein the monomers (iii) are selected from 2-methoxyethyl acrylate (MEA), 2-methoxyethyl methacrylate (MEMA), 2-hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), 2-phenoxy-ethyl methacrylate (PhEMA), 2-phenoxy-ethyl acrylate (PhEA), methyl methacrylate (MMA), methyl acrylate (MA), methacrylic acid (MA-H), acrylic acid (A-H), polyethylene glycol)monomethyl ether acrylate (PEGA), polyethylene glycol)monomethyl ether methacrylate (PEGMA), ethylene glycol dimethacrylate (EGDMA), ethylene glycol acrylate, and mixtures thereof.8 The method according to any one of claims 4 to 7, wherein the monomers (i) are selected from ThEA, CyEA, and mixtures thereof, the monomers (ii) are selected from DEAEA, DEAEMA, APMAA, APAA, DEAA, DMAPA, and mixtures thereof, and the monomers (iii) are selected from MEA, MEMA, PEGA, PEGMA, HEMA, PhEMA, MA-H, EGDMA and mixtures thereof.9 The method according to any one of claims 4 to 8, wherein the copolymer comprises 1-10% monomers (i), 5-50% monomers (ii), and 40-90% monomers (iii).10 The method according to any one of claims 4 to 9, wherein the copolymer comprises 40-90% monomers (iii) comprising MEMA, MEA and PEGA, 1-10% monomers (i) comprising CyEA and ThEA, and 5-50% monomers (ii) comprising DEAEA or DEAEMA or a mixture thereof, or the copolymer comprises 40-90% monomers (iii) comprising MEMA, MEA and PEGA, 1-10% monomers (i) comprising ThEA, and 5-50% monomers (ii) comprising APMAA or APAA or a mixture thereof.11 The method according to any one of the preceding claims, the copolymer being an ABA triblock copolymer, wherein blocks A comprise the uncharged moieties and the nucleobase-containing moieties, and blocks B comprises the positively charged moieties at pH from 2 to 11, adapted to bind the nucleic acids via electrostatic interaction.12 The method according to claim 11 , wherein blocks A comprise monomers (i) and (iii) as described in any one of claims 4 to 10, and blocks B comprise monomers (ii) as described in any one of claims 4 to 10.13 The method according to claim 12, wherein blocks A comprise MEMA, MEA, ThEA and PEGA, and blocks B comprises DEAEA, optionally the copolymer comprising 1-10% ThEA, 5-20% DEAEA, and 70-90% MEMA, MEA and PEGA.14 The method according to any one of the preceding claims, wherein the copolymer is a cross-linked copolymer, optionally a networked copolymer.15 The method according to any one of claims 4 to 14, the copolymer having one of the following compositions as indicated in the table below:wherein DEAEA-X-BLOCK corresponds to the ABA triblock copolymer as described in claim 13, BRANCHED-X-DP300 and BRANCHED-X-DP50 are crossed-linked copolymers having degree of polymerization of 300 and 50 respectively.16 A method according to claim 15, the copolymer having one of the following compositions as indicated in the table below:wherein DEAEA-X-BLOCK corresponds to the ABA triblock copolymer as described in claim 13, BRANCHED-X-DP300 and BRANCHED-X-DP50 are crossed-linked copolymers having degree of polymerization of 300 and 50 respectively.17 A method according to claim 16, the copolymer having one of the following compositions as indicated in the table below:wherein DEAEA-X-BLOCK corresponds to the ABA triblock copolymer as described in claim 13.18 The method according to any one of the preceding claims, wherein the substrate and / or the copolymer is treated with ethylene oxide, resulting in the substrate and / or the copolymer comprising one or more ethylene glycol units,preferably at least some of said units being in the form of polyethylene glycol (PEG).19 The method according to claim 18, wherein the substrate and / or the copolymer is treated with ethylene oxide applied from an ethylene oxide / diluent mixture in which the ethylene oxide concentration is at least 800mg / L, and wherein the treatment is for a period of at least 7 hours, at a temperature of at least 45°C, and at a humidity of at least 50%.20 The method according to any one of the preceding claims, wherein the aqueous sample is a urine sample and the nucleic acid is urinary DNA.21 The copolymer as described in any one of claims 10 to 20.22 The apparatus as described in any one of claims 1 to 20.23 The apparatus according to claim 22, comprising a device for handling water, wherein the substrate which is the copolymer or is provided with said copolymer is operatively connected to the device, and wherein optionally, the device is selected from water pumps, nets, cartridges, syringes, vessels, rods, filters, funnels, and fluid collectors.24 The apparatus according to claim 23, comprising: the cartridge for handling water, wherein the cartridge comprises an inlet, an outlet, and a passageway connecting the inlet and the outlet, and the substrate which is the copolymer or is provided with said copolymer, wherein the substrate is received or receivable in the passageway, and wherein the apparatus is configured to allow the aqueous sample to be introduced into the cartridge through the inlet, pass through the substrate and exit through the outlet such that when the aqueous sample passes through the substrate, the copolymer captures the nucleic acids from the sample.25 The apparatus according to any one of claims 22 to 24, further comprising a size exclusion filter configured to allow water to flow through, wherein the size exclusion filter is operatively positioned upstream of the substrate which is the copolymer or is provided with said copolymer.26 The apparatus according to any one of claims 22 to 25, comprising two flowcontrol components such as funnels, wherein one flow-control component is configured to be positioned upstream of the substrate and the other is configured to be positioned downstream of the substrate, and the two flowcontrol components are operatively in fluid communication with the substrate, thereby directing flow of the aqueous sample through the substrate.27 The apparatus according to any one of claims 23 to 26, wherein the apparatus is designed to allow recirculation of the aqueous sample through the device for handling water, optionally the apparatus comprising a recirculation mechanism configured to recirculate the aqueous sample through the cartridge from the outlet back to the inlet.28 The apparatus according to any one of claims 22 to 27, comprising a vessel for collecting the aqueous sample, wherein the said vessel comprises an outlet allowing the aqueous sample to pass through to the substrate or to the cartridge, and the said vessel is optionally connected or connectable to the substrate or to the cartridge.

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