Attomolar sensors and applications of photoelectric devices with single-layer graphene (SLG) quantum resistive-capacitive (RC) signal transducer modified with organic semiconductor quantum dots

Description

1 / 19 Attomolar Sensors and Applications of Photoelectric Devices with Single-Layer Graphene (SLG) Quantum Resistive-Capacitive (RC) Transducer Signal Modified with Quantum Dots - A Brief Description

[001] The present patent application comprises a system using the PQSOs-GCU chemical assembly, which forms an electrochemical interface allowing its application as a molecular sensor and electro-optical device. This is made possible by the properties of the PQSOs component of the system which, within the photoabsorption properties, allow the photoexcitation of the interface, enabling the exploration of optoelectronic characteristics using measurable quantum RC characteristics of the interface as a transducer signal. FIELD OF APPLICATION

[002] The main application of the technology is in the field of Chemistry, more specifically Electroanalytical Chemistry, aimed at detecting DNA at the attomolar level of sensitivity for clinical and environmental diagnostic purposes. STATE OF THE ART

[003] Document BR102022000630-0 describes a new modified transducer material and its translation mechanism and method for detecting and / or quantifying species of analytical interest with said modified transducer, used for the development of sensors or biosensors applied to methods for detecting and / or quantifying species of analytical interest, which results in an electrode containing discrete energy levels, or continuous levels when appropriately modified, and its entangled electronic / electrochemical transfer mechanism, based on quantum entanglement. The electrode in question is based on one-dimensional (1D) or two-dimensional (2D) structures so that the entangled states can be used as a signal transducer, where these structures have quantized energy states, characterized by their intrinsic electronic properties, which can be modified by state coupling. Petition 870250012540, dated 02 / 14 / 2025, page 9 / 53 2 / 19 quantized forms of other molecules through physical or chemical interactions, resulting in a notable gain in analytical efficiency.

[004] US11561192 protects an ultracompact, passive, wireless sensor using quantum capacitance effect in graphene, which includes at least one graphene quantum capacitance varactor. In some examples, the graphene quantum capacitance varactor includes an insulating layer, a graphene layer disposed on the insulating layer, a dielectric layer disposed on the graphene layer, a gate electrode formed on the dielectric layer, and at least one contact electrode disposed on the graphene layer and making electrical contact with the graphene layer.

[005] Document CN105115947 describes a type of graphene quantum dot sensor and its application in terms of trinitrophenol, belonging to the field of analytical chemistry. Graphene quantum dot and carboxymethyl chitosan solution are mixed, then a quartz sheet is immersed in graphene quantum dot and carboxymethyl chitosan solution, passing through the thin plate of the formation of an electrostatic force with a hyperfluorescence signal. When the contacts of the sheet are with trinitrophenol, the fluorescence signal can decrease significantly. OBJECTIVES OF THE INVENTION

[006] The objective of the invention is to develop attomolar sensors and photoelectric device applications with quantum resistive-capacitive (RC) signal transducer of organic semiconductor quantum dots modified with single-layer graphene (SLG) for DNA detection. ADVANTAGES OF THE INVENTION

[007] The advantage of this invention is to exploit the quantum resistive capacitive (RC) transducer signal of organic semiconductor quantum dots (OSQDs) modified with single-layer graphene (SLG) for attomolar sensors and optoelectronic (photoelectric) device applications. The unique chemical modification of single-layer graphene (SLG) with constituents such as specifically designed organic semiconductor quantum dots (OSQDs), composed of molecules Petition 870250012540, dated 02 / 14 / 2025, page 10 / 53 3 / 19 push-pull π-conjugated organic heterocyclic semiconductors allow the creation of specific quantum resistive-capacitive states due to the superposition of molecular orbital states (SLG and OQDs). DETAILED DESCRIPTION OF THE FIGURES

[008] Figure 1 shows the set of π-conjugated heterocyclic molecules (A to F) (with B to F[3]), synthesized for the development of PQSO-GCU interfaces for molecular sensing and photoelectronic applications. These molecules were used as the PQSO component of the PQSO-GCU interfaces and linked to the GCU by orbital molecular coupling. They have in common the characteristic of containing electron-donating D and electron-accepting A groups coupled through a π-conjugated heterocyclic bridge.

[009] Figure 2a presents the Nyquist capacitive diagrams recorded for the pure GCU and GCU molecularly coupled to molecule A, as shown in Figure 1. These diagrams were measured in an appropriate electrolytic medium composed of a phosphate buffer solution. The Nyquist diagrams were obtained at the open circuit potential of each interface. Figure 2b shows the measurement of the Cq equilibrium of the interface as a function of the electrode potential, revealing the DOS = Cq / e2 of the interface for GCU and the PQSO-GCU system. Here, the PQSO component is composed of molecule A indicated in Figure 1, where the contribution of the PQSO states that compose molecule A is visible around 1.0 V in DOS format.

[010] Figure 3a shows the Cq measured at an equilibrium frequency as a function of electrode potential. The Cq measurement was performed at different stages of interface construction comprising modified GCU with molecule A, molecular coupling of the molecular DNA probe, blank response, and incubation with six different concentrations of target DNA. The relative response RR% of the assay is shown as a function of target DNA concentration (Figure 3b), and as a function of the logarithm of target DNA concentration (Figure 3c).

[011] Figure 4a illustrates the graph of the relative response RR% of DNA assay interfaces comprising different ligand molecules from the compound set. Petition 870250012540, dated 02 / 14 / 2025, page 11 / 53 4 / 19 n-conjugated heterocyclic compounds are illustrated in Figure 1. Figure 4b shows the calibration curves constructed from biological DNA detection assays, within their respective sensitivities, calculated as the slope of these linear graphs.

[012] Figure 5 is a graph showing the comparison between the calibration curve obtained for the DNA detection assay and consecutive incubations in PB solution without the presence of the target DNA, using molecule F as a ligand within the PQSO component of the PQSO-GCU interface.

[013] Figure 6a illustrates the transfer curves obtained for a classic GFET transistor configuration at different target DNA concentrations [21-22]. In this GFET configuration, the GCU surface of the FET was modified with PBSE molecule and subsequently organized with the DNA probe sequence to measure the target DNA sequence and Figure 6b represents the variation of ΔVDirac obtained in the GFET configuration as a function of the target DNA concentration.

[014] Figure 7a shows the capacitive V-shaped push-pull profiles comprising molecule A molecularly coupled to a GCU, obtained by measuring Cq at the equilibrium frequency over an electrode potential range. Measurements of these DOS = Cq / e2 curves were performed concomitantly with photoexcitation within wavelengths in the visible region of the electromagnetic spectrum. Figure 7b shows the Cq determined at the Dirac point (region 1) of the capacitive V-shaped curve measured in Figure 7a as a function of different wavelengths. Figure 7c is the same as Figure 7b, where the Cq responses were measured in region 2 instead of 1, as indicated in Figure 7a. DETAILED DESCRIPTION OF THE INVENTION

[015] This patent application aims to demonstrate the advantages of using quantum resistive-capacitive (RC) signal transducers of heterocyclic organic semiconductor quantum dots (PQSOs) modified with single-layer graphene (GCU) for atomolary sensors and optoelectronic (photoelectric) device applications. The quantum RC architecture of the interface allows the use of Petition 870250012540, dated 02 / 14 / 2025, page 12 / 53 5 / 19 the quantum rate ν = 1 / τ of the PQSOs-GCU chemical assembly as a transducer and field-effect signal. The measurement of the rate ν = 1 / τ is performed by measuring the characteristic time τ = RC associated with the quantum RC components of the PQSOsGCU assembly. The measurement of the rate ν is due to the evaluation of a displacement electric current[1] of this molecular-scale thickness PQSOs-GCU architecture which, in contact with an appropriate electrolytic medium, forms a molecular-scale electrochemical junction. The nature of this displacement electric current depends solely on the singular properties of the quantum capacitance Cq associated with the capacitive component of the quantum RC elements of this molecular-scale device. Consequently, the interface electric current cannot be measured in any other way than by applying a time-dependent potential perturbation in or out of resonance with the quantum RC components of this molecular-scale device.

[016] Synthetic and theoretical studies have demonstrated that replacing the benzene ring of a π-conjugated bridge with easily delocalizable five-membered heteroaromatic rings (e.g., thiophene, pyrrole, benzoxazole) results in enhanced optoelectronic properties of PQSOs [2, 3]. The unique chemical modification of the GCU with specifically designed PQSO constituents, composed of push-pull π-conjugated, semiconductor-type organic molecules, allows the creation of specific quantum RC states due to the superposition of GCU and POQ molecular orbital states. Interestingly, since PQSOs allow the design of a myriad of chemical structures, the quantum RC signal of a GCU-POQ architecture constitutes a versatile and innovative way to design atomolary quantum RC electronic interfaces for a myriad of applications spanning sensors and electro-optical devices.

[017] Figure 1 shows a set of push-pull or donor / acceptor type aromatic heterocyclic molecules, comprising chemical structures containing electron-donating (D) and electron-accepting (A) molecular subunits attached to each end of the conjugated π-bridges. These molecules were designed, Petition 870250012540, dated 02 / 14 / 2025, page 13 / 53 6 / 19 synthesized and characterized molecules were designed to serve as organic semiconductor quantum dots (PQSOs) to be assembled into single-layer graphene (GCU) structures. The PQSO-GCU assembly was assembled through τ-π stacking interactions occurring between π orbitals of PQSOs and GCU electronic structures. The electronic properties of the π-conjugated heterocyclic molecules with graphene were studied by electrochemical impedance spectroscopy (EIS), which served as the chosen time-dependent method for measuring the v-characteristic of the assembly.

[018] For example, the associated quantum RC dynamics av ​​can be obtained thanks to a quantum conductance of the ensemble, which can be combined with the quantum capacitance Cq= e2(dn / dE) (where states and correspond to the elementary charge and (dn / dE) to the density of states), intrinsically leading to electrodynamics that follows a quantum RC dynamics. This can be accessed experimentally by means of an EIE method, in which a complex capacitance function can be obtained as [4]; <7·(ω) = —--C,,o(l - >ω·τ), + (1) where the term Cq,o corresponds to the equilibrium capacitance, which is obtained for ω 0, where the imaginary component of the complex capacitance is negligible. Also in Eq. 1, t = RqCq, corresponds to the characteristic quantum RC relaxation time where Rq= MG ah / e2, summarized in terms of the series combination of circuit elements Rq and Cq of the set. Consequently, the electron transport rate constant is obtained simply as v = 1 / t = E / ha e2 / hCq. The use of Eq. 1 as a time-dependent electrical measurement in an electrochemical environment has been described as quantum rate spectroscopy, which has effectively allowed experimental access to the electronic structure of redox molecular monolayers[5], graphene[6], inorganic quantum dots[7] and π-conjugated molecular assemblies[8]. Petition 870250012540, dated 02 / 14 / 2025, p. 14 / 53 7 / 19 This proves the usefulness and versatility of the approach for measuring the quantum mechanical properties of nanoscale chemical systems in an electrolytic environment.

[019] The energy associated with e2 / Cq is interconnected with the electrostatic energy contribution of the electrolyte e2 / Ce. Cq and the associated density of states dn / dE = Cq / e2(DOS) of the interface can be measured due to the series combination of Ce and Cq, known as electrochemical capacitance 1 / Cp = 1 / Ce + 1 / Cq. The presence of cations and anions in the electrolyte allows for shielding of the electric field associated with both the electron and holes during the charging of the electrochemical capacitance Cp of the system.The shielding of the electric field allows Ce to be of the same order of magnitude as Cq, such as Ce ~ Cq, leading to e2 / Cp = e2 / Ce + e2 / Cq = 2e2 / Cq due to Ce ~ Cq, and 2 is accounted for as an energy degeneracy ge = 2 due to e2 / Ce ~ e2 / Cq, which has been demonstrated experimentally[4, 9,10] in experiments conducted in an electrolytic medium. Effectively, if spin degeneracy is accounted for, then the total degeneracy of E is E = gsge(e2 / hCq), where gs is the electron spin degeneracy and ge is the energy degeneracy state associated with the shielding effect of the electrolyte's electric field on the molecular states.

[020] There are two equivalent interpretations of ge degeneracy. The first is based on the existence of resonant electric currents, which are time-dependent (displacement) electric currents within the junction. This type of resonant electric current is due to the existence of two charge carriers (electrons and holes) that promote a total current here denoted as io. The origin of this displacement electric current is due to the role played by the electrolyte, which allows the superposition of the electrostatic Ce and quantum capacitive Cq modes. In this situation, the elementary charge e is subject to an equivalent electric potential, i.e., e / Ce ~ e / Cq, leading locally to Ce ~ Cq.

[021] As explained above, the equivalent capacitance Cp of the junction is 1 / Cp = ge / Cq, with an energy degeneracy of e2 / Cp = gee2 / Cq. This energy degeneracy is equivalent to the previous electric current degeneracy geio, Petition 870250012540, dated 02 / 14 / 2025, p. 15 / 53 8 / 19 is considered the origin of ge, because 1 / ϋμ = 2 / Cq implies Cq = 2μ. Since the interface capacitance is the result of the equivalent contribution of Ce and Cq, there is a degeneracy of electric current to charge the quantum capacitive states of the interface that is proportional to Cμ with an electric current of io = CμS = (1 / 2) (Cq)s. This is equivalent to geio = CqS, where s = dV / dt is any potential time perturbation (scan rate) imposed on the system to investigate energy states E = e² / Cq coupled to the probe electrode. Note that the electric current io can only be measured in association with the meaning of Cq and with DOS = Cq / e²e, therefore it can only be accessed through a time-dependent electric field / potential perturbation. Therefore, the use of Cq as a transducer signal for sensors and photoelectric device applications, for example, implies a very specific type of time-dependent field-effect signal transducer.

[022] In this patent application, it will be demonstrated that the PQSOsGCU chemical assembly forms an electrochemical interface that allows its application as a molecular sensor and electro-optical device. This is made possible by the properties of the PQSOs component of the system which, within the photoabsorption properties that allow photoexcitation of the interface, allows exploiting optoelectronic characteristics using measurable quantum RC characteristics of the interface as a transducer signal. The optoelectronic characteristics of the assembly are modulated by the known photoinduced intramolecular charge transfer of PQSOs

[11] .

[023] Figure 2a compares Nyquist capacitive diagrams recorded at the open circuit potential (OCP) for pure GCU and PQSOs-GCU systems. The diameter of the semicircle-shaped region of the Nyquist diagram allows the Cq value associated with the RC quantum dynamics to be graphically obtained, which for pure GCU corresponded to a value of ~ 4.0 μF cm-2, as shown in Figure 2a. However, when assembling PQSOs (particularly in Figure 2, corresponding to the molecule indicated as A in Figure 1) on GCU, changes in the quantum shape of the RC circuit are observed, associated with a decrease in the diameter of the semicircle. Petition 870250012540, dated 02 / 14 / 2025, page 16 / 53 9 / 19 Nyquist, corresponding to a Cq value of ~ 2.7 pF cm-2 for this PQSOGCU interface, identified in the figure as A-GCU. The modification, and the specific contribution of the assembly of molecule A on the GCU, is more visible by investigating the dn / dE (DOS) of the interface, which is obtained by measuring Cq = e2(dn / dE) as a function of the electrode potential at a specific fixed frequency, corresponding to the equilibrium frequency and called ω o, identified as the frequency at which the semicircle closes. The DOS of the GCU and A-GCU systems are compared in Figure 2b. The arrow in Figure 2b indicates a specific molecular orbital coupling between molecule A and the GCU. This can be studied equivalently by means of impedance spectroscopy, also using the electrodynamics of Eq. 1, specifically in the bias where this orbital coupling occurs (between molecule A and the GCU).

[024] In summary, the complex capacitive response, corresponding to a quantum RC dynamics of pure and PQSO-modified GCU, reveals the specific electronic changes caused by the coupling of molecular orbital states of PQSOs to the GCU. Furthermore, the complex capacitive response allowed the identification of the equilibrium frequency ω o of pure GCU and A-GCU systems, from which the DOS = Cq / e2 of these electrochemical bonds at the molecular scale was measured, as illustrated in Figure 2b. In the specific case of pure GCU, a characteristic response was achieved in the form of a highly symmetric and well-known V, as expected for the Cq response of this type of interface. The assembly of molecule A to the GCU resulted in characteristic modifications of the DOS = Cq / e2 profile, as a result of the molecular orbital coupling of PQSO (molecule A) to the GCU.The characteristic changes mainly include a shift in the minimum of the V shape towards more negative potentials within the losses in the characteristic capacitive V shape symmetry. Furthermore, by examining the positive potential region of the DOS, it is possible to identify an additional contribution from molecule A to the DOS of the PQSO-GCU system, as highlighted in Figure 2b.

[025] Measuring the DOS = Cq / e2 interface by measuring the Cq component Petition 870250012540, dated 02 / 14 / 2025, page 17 / 53 10 / 19 of the quantum RC dynamics of the PQSO-GCU system demonstrates the existence of a unique quantum RC electrodynamics. Therefore, the molecular coupling between the GCU and the π-conjugated A molecule can be used not only to characterize the electronic structure of the interface, but also as a very useful transducer signal for molecular detection and diagnostics. Consequently, the minimum of the capacitive Cq-V form can serve as a transducer signal for molecular detection devices. This Cq signal was the specific region of DOS used as a transducer signal to demonstrate the proof of principle of the methodology described here. The interface designed by A-GCU will be specifically employed as an interface platform for atomolar-level DNA detection. To demonstrate and prove the principle of operation, a target DNA sequence consisting of single-stranded DNA associated with the C228T mutation in glioblastoma was used as the receptor sequence.

[026] To detect the target DNA sequence, a DNA probe receptor sequence was linked to molecule A within the PQSO-GCU structure by chemical activation of the carboxylic acid molecular subunits. This allowed the formation of an amide bond to couple the DNA probe sequence to the PQSO-GCU structure, resulting in a biological detection interface. The stability of the transducer signal was determined by measuring a blank signal that includes measuring the Cq of the interface after incubation with hybridization buffer solution without the presence of target DNA. Small changes in the Cq signal (but insignificant relative to the positive) are expected between consecutive measurements of the interface blank Cq. Consequently, the response of this biological detection interface was evaluated by measuring Cq at the minimum of the V form at different concentrations of target DNA, ranging from 1.0 to 105 aM.The incubation time and volume for each concentration were 1 hour and 20 pL, respectively.

[027] Figure 3a represents the Cq responses recorded at different stages of construction of the biological detection interface (coupling of molecule A to the GCU, the DNA probe to molecule A, and so on), for six concentrations Petition 870250012540, dated 02 / 14 / 2025, p. 18 / 53 11 / 19 different from the target DNA. It is possible to note that the characteristic capacitive V-shaped response of the interface changes through the modification of the GCU with molecule A, and molecule A with the probe. However, after the coupling of the target DNA, even at the initial concentration, visible changes occur in the V-shape, which becomes more pronounced as the target DNA concentrations increase. The observed changes in the V-shape are especially visible in the minimum Cq value characteristic of the V-shape, corresponding to the Dirac point. There is a clearly visible decrease in the absolute value of Cq with increasing target DNA concentrations. This decrease in Cq with increasing target DNA concentration can be used as a transducer signal for the construction of analytical curves.In fact, the relative response (RR%) of the inverse of the Cq value (associated with the interface energy state E = e2 / Cq) at the minimum of the V form of the GCU (at -0.5 V) was calculated using the expression RR% = [(1 / Cq - 1 / Cq-blank) / (1 / Cq-blank)] * 100, where 1 / Cq and 1 / Cq-blank correspond to the inverse of the Cq value at the minimum of the V form for each target DNA concentration and the blank, respectively. Figure 3 shows the construction of the analytical curve using the RR% variation of the interface as a function of the target DNA concentration. The resulting graph shown in this figure was fitted using the Langmuir isotherm model, as illustrated in Figure 3b, yielding an excellent fit parameter (R2 = 0.999). This demonstrates that the variations recorded in this characteristic (1 / Cq) are associated with the specific interaction between the probe and the target DNA, allowing the construction of useful linear analytical curves, as shown in Figure 3c.

[028] The linearity of the analytical curve was observed through mathematical fitting to a linear function, leading to approximately 0.998 for the linear statistical correlation, thus confirming the linear pattern of the 'curve' and allowing an estimated sensitivity of 19.37% per decade in this DNA assay. Other analytical values ​​of merit, such as the limits of detection (LoD) and quantification (LoQ), were calculated as 0.51 and 2.67 aM, respectively, highlighting the ultrasensitive nature of DNA assays based on the Cq response of a PQSO interface. Petition 870250012540, dated 02 / 14 / 2025, page 19 / 53 12 / 19 GCU designed. As the results prove the use of the Cq signal from this interface as a highly promising platform for DNA molecular assay, molecules B to F, illustrated in Figure 1, were meticulously designed, synthesized, and characterized as chemical modifiers of GCU. Note that three of these sets of molecules were synthesized exclusively for testing on this platform (C, E, F), while two (B

[12] and D

[13] ) have already been used in other applications. As documented elsewhere, the effectiveness of π π stacking between aromatic structures depends on the planar characteristics and the number of π orbitals

[14] . A larger number of aromatic rings containing π orbitals allows a greater number of orbitals to be coupled to the GCU, for example.Therefore, the incorporation of planar molecular subunits of pyrene and naphthalene into the π-conjugated molecular structure has the ability to improve electronic coupling with GCU structures and, consequently, increase the sensitivity of biological and molecular assays based on the coupling of these specific PQSOs to GCU.

[029] Using PQSOs-GCU structures with PQSOs components comprising π-conjugated molecules of type B to F (as shown in Figure 1), assays were performed with DNA, and their effectiveness was evaluated in PQSO components designed differently from PQSOs-GCU structures, following an approach similar to that used in the binding of molecule A to GCU. The graphs representing the RR% as a function of concentration, as well as the logarithm of the latter, are presented in Figure 4, offering relevant information on the influence of the PQSO type on the PQSOs-GCU set and its use in DNA and molecular assays. Note that all graphs represented in Figure 4a exhibited exceptionally good fits to the Langmuir isothermal model, confirming the response to different concentrations of target DNA. Note also that in all situations, the molecular occupancy of the target DNA on the receptor DNA at the interface followed the Langmuir isothermal model.Figure 4b shows the calibration curves derived for this set of molecules. Comparative analysis demonstrates that, despite the... Petition 870250012540, dated 02 / 14 / 2025, page 20 / 53 13 / 19 atomolar efficiency of molecule A, used as a PQSO component in the PQSOs-GCU set for DNA assay, demonstrated the worst performance among all other molecules tested as PQSO components of the interface. This was attributed to the lack of planarity of the donor group (triphenylamino group) of molecule A, while in the other molecules the donor group consists of fused aromatic rings: naphthalene (molecule B), or pyrene (molecule CF). Thus, molecule A exhibited a sensitivity of 19.42% per decade of target DNA concentration, which was the lowest among the set of molecules A to F shown in Figure 1, which were used as PQSO components of different DNA detection interfaces.For example, when using molecule B as the PQSO component of the DNA detection interface, featuring a naphthalene subunit as group D, the measured sensitivity was estimated at ~37.77%, that is, at least twice the sensitivity obtained for the target DNA analyzed using molecule A as the PQSO component of the interface.

[030] The sensitivity of assays employing heterocyclic molecules with a pyrene molecular fragment as the D group ranged from 76.87% to 135.12%, highlighting the potential to increase the sensitivity of this sensor configuration, in which there is a specific interaction between the molecule (with four fused conjugated aromatic rings) and pure GCU. The variation in sensitivity values ​​obtained for this set of molecules can be attributed to distinct π bridges and receptor groups present in the structure of the PQSO components. The DNA molecular assay involving the F molecule as the PQSO component of the interface exhibited the highest sensitivity within the entire set of heterocyclic molecules, reaching a value of 132.12% per decade of DNA concentration. This molecule comprises pyrene, thiophene, and carboxylic acid molecular subunits as D, π bridge, and A groups, respectively.The analysis reveals an increase in already notable sensitivity, based on the design of the chemically coupled PQSO structure to the GCU, demonstrating the possibility of controlling the assay's detection parameters through adaptation of the chemical structure. Petition 870250012540, dated 02 / 14 / 2025, p. 21 / 53 14 / 19 π-conjugated heterocyclic molecule that acts as a PQSO. Table 1 lists calculated LoD and LoQ for different DNA assays.

[031] Table 1 - Limits of detection (LoD) and quantification (LoQ) [aM] calculated for the different DNA detection assays using the complete set of push-pull molecules from A to F represented in Figure 1. Molecule LoD [aM] LoQ| [aM] A 0.51 2.68 B 0.33 2.12 c 0.21 1.73 D 0.24 1.80 E 0.34 2.15 F 0.11 1.37 Table 1

[032] Figure 5 shows a comparative analysis of the analytical response RR% with a sensitivity of 135.12% for the PQSO-GCU system, comprising the F molecule as the PQSO component, compared to the negligible sensitivity response of 2.4% of the blank. Furthermore, the quantum RC methodology offers advantages in terms of sensitivity compared to the traditional DC mode of operation of graphene field-effect transistors (FETs). DNA assays targeting the same C228T DNA mutation were conducted using GCU FETs modified with pyrenebutyric acid succinimidyl ester (PSBE) molecules, which served as a ligand to immobilize the probe DNA sequence. Figure 6a shows that the transfer curves recorded for this graphene FET, including changes in the minimum electrostatic potential at the Dirac point ( / D / fac) and the iDS current for a given VGS, are all sensitive to the target DNA concentration.Thus, by considering the variation of VGS in VDirac for each target DNA concentration as the sensor's transducer signal, the position of VDirac relative to the blank (PB buffer without target DNA) can be monitored as variations in the value illustrated in Figure 6b. It can be observed that A^D / rac varies. Petition 870250012540, dated 02 / 14 / 2025, page 22 / 53 15 / 19 consistently, becoming more negative and varying linearly as a function of the logarithm of the target DNA. This response allows for quantitative DNA detection, with a LoD of 10 aM and a dynamic range of approximately 3 decades before saturation is reached. Therefore, DNA assays constructed using the traditional GFET configuration and conventional ligand molecules showed higher LoD and lower sensitivity compared to assays using the quantum RC configuration within π-conjugated heterocyclic compound molecules as ligand molecules.

[033] Push-pull π-conjugated heterocyclic molecules exhibit advantageous optoelectronic properties and can be used as versatile organic components in the fabrication of semiconductor materials, in nonlinear optics, dye-sensitized solar cells (DSSCs), organic light-emitting diodes (OLEDs), as optical chemosensors and probes for bioimaging, among others [15-20]. Additionally, they can also be used for the development of ultrasensitive photosensitive devices in quantum RC measurement format.

[034] Photoexcitation energy applied to push-pull molecular structures triggers intramolecular charge transfer (ICT) mechanisms, leading to access to excited electronic states of the molecules and, subsequently, to measurable electron relaxation processes[2]. Considering that the quantum RC measurement methodology allows revealing the electronic structure of electrochemical interfaces, such as modified and unmodified GCU, through the measurement of DOS = Cq / e2 whenever different wavelengths in the visible light spectrum are applied to PQSO-GCU systems in which the PQSO component of the interface absorbs in the UV-VIS region of the spectrum, there is a variation in the capacitive V-shape of the interface after the absorption of photons by the PQSO component, as shown in Figure 7a. This figure specifically shows Cq responses of the V-shape as a function of different wavelengths or photoexcitation energies.It can be observed that Figure 7a highlights two regions in the graphs. Petition 870250012540, dated 02 / 14 / 2025, p. 23 / 53 16 / 19 V-shaped capacitive elements. A decrease in Cq is observed in both regions denoted as (1) and (2), represented in Figures 7b and 7c, respectively. Region 1 of the DOS curve corresponds to the Dirac point of the GCU, while the response of region 2 of the DOS corresponds to a specific electronic state associated with the molecular orbital coupling established between the push-pull molecules and the GCU structure. Due to this molecular orbital coupling between the push-pull molecule and the GCU, both responses are altered through photoexcitation of the coupled system. It can be observed that the variation of Cq corresponding to region 2 is greater as a function of wavelength energy compared to the variation associated with region 1.Thus, changes in the Cq response in these two regions of the DOS, which is linked to the electronic structure of the entire coupled system and is evaluated through a photoexcitation perturbation, can serve different purposes, including photoexcitation-enhanced transducer signals, photoelectron detection, and so on.

[035] These photoelectrochemical signals become particularly valuable when a biological event, such as the interaction between the probe and the target DNA strands under photoexcitation conditions, is captured by changes in the electronic structure of the detection interface, GCU. This is done by measuring DOS = Cq / e2, and whenever different wavelengths in the visible light spectrum are applied to PQSO-GCU systems in which the PQSO component of the interface absorbs in the UV-VIS region of the spectra, there is a variation in the capacitive V-shape of the interface after the absorption of photons by the PQSO component, as shown in Figure 7a. This figure, in particular, shows Cq responses of the V-shape as a function of different wavelengths or photoexcitation energies. Figure 7a highlights two regions in the capacitive V-shape graphs. Furthermore, a decrease in Cq is observed in both regions denoted as 1 and 2, represented in Figures 7b and 7c, respectively.Region 1 of the DOS curve corresponds to the Dirac point of the GCU, while the response of region 2 of the DOS corresponds to a specific electronic state associated with the molecular orbital coupling established between them. Petition 870250012540, dated 02 / 14 / 2025, page 24 / 53 17 / 19 push-pull type molecules and the GCU structure. Due to this molecular orbital coupling between the push-pull type molecules and the GCU, both responses are altered through photoexcitation of the coupled system. Note that the Cq variation corresponding to region 2 is greater as a function of wavelength energy compared to the Cq variation associated with region 1. Thus, changes in the Cq response in these two regions of the DOS, which are linked to the electronic structure of the entire coupled system and evaluated through a photoexcitation perturbation, can serve different purposes including photoexcitation-enhanced transducer signals, photoelectron detection, and so on. These photoelectrochemical signals become particularly useful when a biological event, such as the interaction between the probe and the target DNA strands under photoexcitation conditions, is captured by changes in the electronic structure of the detection interface, for example.

[036] REFERÊNCIAS BIBLIOGRÁFICAS • BUENO, P. R.; MERCADO, D. A. M. Quantum rate theory for graphene. The Journal of Physical Chemistry C, ACS Publications, v. 126, n. 36, p. 1537415385, 2022. • BURES, F. Fundamental aspects of property tuning in push-pull molecules. Rsc Advances, Royal Society of Chemistry, v. 4, n. 102, p. 58826-58851,2014. • RAPOSO, M. M. M. et al. Synthesis and characterization of dicyanovinylsubstituted thienylpyrroles as new NLO-chromophores. Organic Letters, ACS Publications, v. 8, n. 17, p. 3681-3684, 2006. • BUENO, P. R. Quantum rate theory and electron transfer dynamics: A theoretical and experimental approach for quantum electrochemistry. Electrochimica Acta, 2023. • BUENO, P. R. Quantum rate theory and electron-transfer dynamics: A theoretical and experimental approach for quantum electrochemistry. arXiv preprint arXiv:2305.18359, 2023. • LOPES, L. C.; SANTOS, A.; BUENO, P. R. Measuring quantum conductance and Petição 870250012540, de 14 / 02 / 2025, pág. 25 / 53 18 / 19 capacitance of graphene using impedance-derived capacitance spectroscopy. Carbon, Elsevier, v. 184, p. 821-827, 2021. • PINZÓN, E. F. et al. Quantum rate as a spectroscopic methodology for measuring the electronic structure of quantum dots. arXiv preprint arXiv:2302.12887, 2023. • NIETO, E. F. P. et al. Quantum rate electrodynamics and resonant junction electronics of heterocyclic molecules. arXiv preprint arXiv:2309.05754, 2023. • ALARCON, E. V. G.; SANTOS, A.; BUENO, P. R. Perspective on quantum electrochemistry. a simple method for measuring the electron transfer rate constant. Electrochimica Acta, v. 398, 2021. ISSN 0013-4686. • SANCHEZ, Y. P.; SANTOS, A.; BUENO, P. R. Quantum mechanical meaning of the charge transfer resistance. Journal of Physical Chemistry C, v. 126, n. 6, p. 3151-3162, 2022. ISSN 1932-7447. • SAMANTA, P. K.; MISRA, R. Intramolecular charge transfer for optical applications. Journal of Applied Physics, AIP Publishing, v. 133, n. 2, 2023. • WANG, H.; DYMOCK, B. W. New patented histone deacetylase inhibitors. Expert opinion on therapeutic patents, v. 19, n. 12, p. 1727-1757, 2009. • BAHETI, A. et al. Pyrene-based organic dyes with thiophene containing π-linkers for dye-sensitized solar cells: optical, electrochemical and theoretical investigations. Physical Chemistry Chemical Physics, Royal Society of Chemistry, v. 13, n. 38, p. 17210-17221,2011. • ZHANG, Z. et al. Tailoring electronic properties of graphene by π- π stacking with aromatic molecules. The Journal of Physical Chemistry Letters, ACS Publications, v. 2, n. 22, p. 2897-2905, 2011. • KHASBAATAR, A. et al. From solution to thin film: Molecular assembly of πconjugated systems and impact on (opto)electronic properties. Chemical Review, ACS Publications, v. 123, n. 13, p. 8395-8487, 2023. • OLIVA, M. M. et al. Structure-property relationships in push-pull aminocyanovinyl end capped oligothiophenes: quantum chemical and experimental Petição 870250012540, de 14 / 02 / 2025, pág. 26 / 53 19 / 19 studies. Journal Organic Chemistry, ACS Publications, v. 71, n. 20, p. 75097520, 2006. • FERNANDES, S. S. M. et al. Optical and photovoltaic properties of thieno[3,2b]thiophene based push-pull organic dyes with different anchoring groups for dye-sensitized solar cells. ACS Omega, ACS Publications, v. 2, n. 12, p. 92689279, 2017. • BATISTA, R. M. F.; COSTA, S. P. G.; RAPOSO, M. M. M. Selective colorimetric and fluorimetric detection of cyanide in aqueous solution using novel heterocyclic imidazo-anthraquinones. Sensors and Actuators B: Chemistry, ACS Publications, v. 191, p. 791-799, 2014. • SOUSA, R. P. C. L. et al. Hybrid sol-gel matrices doped with colorimetric / fluorimetric imidazole derivatives. Nanomaterials, MDPI Publications, v. 11, n. 12, p. 3401,2021. • GONÇALVES, R. C. R. et al. Bioimaging of lysosomes with a BODIPY pHdependent fluorescent probe. Molecules, MDPI Publications, v. 27, n. 22, p. 8065, 2022. • CAMPOS, R. et al. Attomolar label-free detection of DNA hybridization with electrolyte-gated graphene field-effect transistors. ACS Sensors, ACS Publications, v. 4, n. 2, p. 286 - 293, 2019. • VIEIRA, N. C. S. et al. Graphene field-effect transistor array with integrated electrolytic gates scaled to 200 mm. Journal of Physics: Condensed Matter, Institute of Physics Publishing, v. 28, 085302, 2016. Petição 870250012540, de 14 / 02 / 2025, pág. 27 / 53

Claims

1 / 6 CLAIMS 1. An Attomolar Sensor, characterized by the correlation between quantum conductance i / fi? oc e2 / he and quantum capacitance cq, allowing the definition of a quantum circuit Rqcq that controls the dynamics of electron transport and electronic communication in low-dimensional structures such as dimensionless (OD), one-dimensional (1D) and two-dimensional (2D) structures embedded in an electrolyte medium and in contact with a metallic probe, wherein the quantum mechanical properties associated with the electronic structure of these materials can be determined by the electrochemical measurement of ca_ = e2(d?i / df), where (díi / df) is the electronic state density function, since Ra: = h / e7· is a universal constant.

2. Attomolar Sensor, according to claim 1, characterized by the characteristic time of the quantum circuit r = Rqcq = being only dependent on the function (dn / df), wherein the quantum temporal state can therefore only be accessed by alternating current (AC) measurements or transient measurements and the transport will occur by means of a displacement electric current i0 associated with the cq of the material such that id<*cqs, where s = dv / dt is any temporal perturbation of the electric potential v as a function of time that originates the measured response id.

3. Attomolar Sensor, according to claim 2, characterized in that a time-dependent perturbation (s = dv / dt) allows the determination of a total current flux j(f) = id / A which is the sum of the displacement current e(dE / dt) associated with the electrochemical medium and the particle current such that j(f) = e(dE / dt) + jp(r), where r is the particle position vector and ε = εΓε0 is the dielectric constant of the medium, with εΓ being the relative dielectric constant and ε0 the electric permeability in vacuum and ee is the associated electric field vector av, wherein the total current j(f) must be conserved such that v JV) = o. Petition 870250012540, dated 14 / 02 / 2025, page 28 / 53 2 / 6 4. Attomolar Sensor, according to claim 1, characterized by low-dimensional structures (0D, 1D and 2D) which may be: - One-dimensional (0D) structured materials are nanoscale with electronic constraints in 3 dimensions, wherein these materials are molecules and quantum dots in general of interest in sensor, electronic and optoelectronic applications;- One-dimensional (1D) structured materials are nanoscale in one dimension, where electrons are confined to one dimension, indicating that they cannot move freely. Examples of these structures include single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene nanoribbons, inorganic semiconductor nanowires (Group IV Si and Ge nanowires, Group III-V InAs, GaAs, GaN nanowires, Group II-VI CdS, CdSe, ZnSe nanowires, and metal oxide nanowires such as ZnO and SnO2), and organic molecular semiconductors of the DnA type, where D is an electron donor group, A is an electron acceptor, and π is a conjugated heterocyclic bridge to which the D and A groups are attached at each end of the push-pull system.- Two-dimensional (2D) materials are scaled to the nanoscale in two dimensions, where electrons are confined within two dimensions, indicating that electrons cannot move freely but only within the 2D plane. Examples of these structures include graphene and its derivatives (graphene obtained by chemical vapor deposition, epitaxial graphene grown on silicon carbide substrates, graphene obtained by mechanical exfoliation, graphene oxide and reduced graphene oxide obtained by the Hummers method, crumpled graphene, graphene nanoribbons); graphene doped with nitrogen, phosphorus, sulfur, oxygen, boron, as well as atoms belonging to the alkali metal and halogen groups; nanocomposites formed by graphene / metallic nanoparticles, graphene / conductive polymers, graphene / carbon nanotubes, 2D materials in addition to graphene (black phosphorus, MoS2, WSe2 h-BN, CrS2, CrO2, VS2, VO2, NbSe2);Boron nitride Petition 870250012540, dated 02 / 14 / 2025, page 29 / 53 3 / 6 hexagonal and its nanocomposites with metallic nanoparticles, polymers, carbon nanomaterials (graphene and nanotubes).; 5. Attomolar Sensor, according to claim 4, characterized by electrodes made of 2D materials combined with organic semiconductor structures OD or 1D (of the D-ττ-A type) specially designed to rationally modify the 2D structures, employing the use of alternating current (AC operating mode).

6. Attomolar Sensor, according to claim 3, characterized by being much more sensitive and precise than currently available for application in health (disease diagnosis, discovery of new compounds), environment (detection of pesticides, chemical weapons, water contaminants, ecological pollution control), food industry (detection of bacteria, chemical and biological contaminants, quality control), where the analyte detection may require low-dimensional materials (OD, 1D and 2D) in combination, and modifications of these with other low-dimensional materials (OD, 1D and 2D) can serve to increase sensitivity through the formation of a new cq = ez(dn / dE) structure or as chemical and biological receptors.

7. Attomolar Sensor, according to claim 6, characterized in that the anchored receptor is based on aptamers, antibodies, antigens, antibody fragments, oligosaccharides, peptides, cells, bacteria, viral particles, enzymes and proteins.

8. Attomolar Sensor, according to claim 7, characterized in that the analyte recognized by the docked receptor can be aptamers, antibodies, antigens, antibody fragments, oligosaccharides, peptides, cells, bacteria, viral particles, enzymes and proteins.

9. Atmolar sensor, according to claim 6, characterized by qualitatively or quantitatively recognizing the analyte, and detecting more than one analyte. Petition 870250012540, dated 02 / 14 / 2025, page 30 / 53 4 / 6 10. Use of the Attomolar Sensor, according to claim 6, characterized by being employed for the study of chemical and biological affinity and the study of the kinetics associated with chemical and biological affinities.

11. Attomolar Sensor, according to claim 6, characterized in that the sensors are point-of-care devices, are portable, and allow for rapid, real-time diagnostic testing.

12. Attomolar Sensor, according to claim 1, characterized in that the electrical contact is made by means of materials of titanium / gold, titanium / platinum, chromium / gold, platinum, pure silver, silver / tin, silver / nickel, and other types of silver, silver / cadmium oxide, silver / tin oxide, tungsten / silver, tungsten / copper, phosphorus activation in epitaxial Si, Ge, Gei-xSnx, SiyGei-x-ySnx.

13. Attomolar Sensor, according to claim 3, characterized by the electric current J(f) being accessed through time-dependent and / or transient measurements (the AC mode being a specific type) in which the values ​​of the Rq and cq components that make up the characteristic time of the process (in the case of AC type harmonic electrical measurements) can preferably, but not exclusively, be obtained: - From the impedimetric Nyquist (Z' versus -Z”) and capacitive Nyquist (C' versus C”) and impedimetric Bode (Z' or Z” versus logarithm of frequency) and capacitive (C' or C” versus logarithm of frequency) plots, the data corresponding to the components of the quantum entanglement are obtained, where Z' and Z” correspond, respectively, to the real component and imaginary component of the complex impedance function, similarly, C' corresponds to the real component and C” corresponds to the imaginary component,where the real component is related to the imaginary part of the impedance C = Z” / ω|Ζ|2 and the imaginary capacitive component to the real part of the impedance C = Ζ' / ω|Ζ|2, where the measured complex impedance function ζ*(ω) can be converted into the complex capacitance function c*(w) by the relation c*(w) = 1 / / ωΖ*(ω), j = / ÃL and ω corresponds to the angular frequency which is given by ω = 2ττ / , where f is the frequency; Petition 870250012540, of 14 / 02 / 2025, page 31 / 53 5 / 6 - The peak frequency of the capacitive Bode plot of the imaginary component corresponds to the resonance frequency or the value of i / τ, where this rate is associated with the quantum electrodynamics of the system; - The value of the capacitance (real component) at a specific angular frequency of the capacitive Nyquist plot, it corresponds to the q-value of the entangled state whenever q-value dominates the electrochemical equivalent capacitance response of the state.The frequency can be monitored in different media and analyzed against a potential range, in order to obtain the corresponding quantum conductance (qc) as a function of the potential; - The capacitance value (imaginary component at a typical process frequency) multiplied by the characteristic angular frequency obtained from the capacitive Nyquist plot corresponds to the quantum conductance g = 1 / Rq of the state, and the frequency can be monitored in different media and analyzed against a potential range, in order to obtain the corresponding g = 1 / Rq as a function of the potential.

14. Attomolar Sensor, according to claim 1, characterized by the change of quantum state occurring due to: - Variation of the temporal quantized energy states as a function of the concentration of species present in the medium connected to the low-dimensional materials (OD, 1D and 2D); - Variation of the quantized states according to the physicochemical characteristics of the medium connected to the low-dimensional materials (OD, 1D and 2D); - Variation of the temporal quantized energy states as a function of the intensity of photons reaching the low-dimensional materials (OD, 1D and 2D); - Variation of the temporal quantized energy states as a function of the intensity of electromagnetic radiation reaching the low-dimensional materials (OD, 1D and 2D); - Variation of the temporal quantized energy states as a function of a temperature variation in the low-dimensional materials (OD, 1D and 2D); Petition 870250012540, dated 02 / 14 / 2025, page.32 / 53 6 / 6 - Variation of temporal quantized energy states as a function of varying mass in low-dimensional materials (0D, 1D and 2D); - Variation of temporal quantized energy states as a function of varying electric or magnetic fields in low-dimensional materials (0D, 1D and 2D).

15. Attomolar Sensor, according to claim 14, characterized by the change of quantum state also occurring as a function of physical or chemical modification in low-dimensional materials (0D, 1D and 2D) due to electroactive or non-electroactive molecules. Petition 870250012540, dated 14 / 02 / 2025, pp. 33 / 53

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