Metal-organic framework for electrochemical biosensor electrode, working electrode for electrochemical biosensor including same, electrochemical biosensor, and manufacturing methods therefor

Abstract

The present invention relates to: an electrochemical biosensor capable of effectively and sensitively detecting alfuzosin; an electrode applied thereto; a metal-organic framework (MOF) which includes a zinc / cobalt oxide and is applied in manufacturing the electrode; and methods for manufacturing same.

Description

Metal-organic framework for electrochemical biosensor electrode, working electrode for electrochemical biosensor including same, electrochemical biosensor and method for manufacturing same

[0001] The present invention relates to an electrochemical biosensor capable of effective and sensitive detection of alfuzosin, an electrode applied thereto, and a metal-organic framework (MOF) comprising zinc / cobalt oxide applied in the manufacture of the electrode.

[0002] Benign prostatic hyperplasia (BPH) is a noncancerous growth of the prostate gland that commonly affects men. It can block the urinary tract, leading to bladder and urinary tract infections and kidney problems. Alpha-adrenergic blockers are the current standard of care for BPH, and alfuzosin hydrochloride (AFZ) is a commonly prescribed medication.

[0003] α1-adrenoceptors are located in the smooth muscles of the bladder neck and prostate, and alfuzosin (AFZ) blocks these receptors, relaxing the smooth muscles and allowing urine to flow more freely. AFZ is generally well-tolerated, but can cause side effects such as dizziness, headache, and hypotension. Rarely, AFZ can cause more serious side effects, such as orthostatic hypotension, priapism, and hypersensitivity reactions. Because of this potential for side effects, it is important to monitor AFZ levels in patients taking this medication.

[0004] Uric acid (UA)-lowering medications have been suggested to potentially reduce urinary tract symptoms associated with BPH and potentially reduce the need for traditional BPH medications, such as alpha-blockers. BPH is more common in men with high UA levels and gout, particularly in younger men with gout. Excessive UA in BPH patients can cause tissue damage, inflammation, and deposition, which can lower the prostate-specific antigen (PSA) level.

[0005] For these reasons, optimizing BPH treatment requires considering the potential side effects of AFZ and closely monitoring patients, especially those with elevated UA levels or a history of gout. Selectively detecting AFZ in the presence of UA has been a challenging task for researchers. Various analytical methods, such as chromatography, conductivity, potentiometric, and spectrophotometric methods, have been proposed to detect AFZ. Despite their effectiveness, these methods are expensive, time-consuming, and require complex chemical processes that require skilled analysts to operate the equipment. Furthermore, they present the additional problem of not providing insight into the pharmacological activity or reaction mechanism of the drug. In contrast, electrochemical approaches have attracted considerable attention due to their rapid response time, low cost, high sensitivity, ease of handling, and economic feasibility. Furthermore, these approaches hold significant potential for investigating the redox reactions of drugs and providing essential pharmacological and pharmacodynamic insights.

[0006] However, reports on the application of electrochemical approaches to determine AFZ remain limited. Therefore, there is a growing need to develop simple, inexpensive, and sensitive electrochemical sensors for detecting AFZ.

[0007] Only a few electrochemical techniques using glassy carbon electrodes have been used for the electrochemical analysis of AFZ.

[0008] Additionally, the development of electrochemical sensors based on pn heterojunctions is a promising area of ​​research, as these sensors have the potential to be more sensitive, selective, and cost-effective than conventional electrochemical sensors.

[0009] Metal-organic frameworks (MOFs) are a unique class of porous crystalline materials with exceptional properties, including open metal sites, organic linkers, tunable functionality, high surface area, and thermal stability. These properties have led to extensive applications in gas sensing, energy storage, drug delivery, and electrocatalysis. Due to their exceptional structural properties, MOFs have also been recognized as potential candidates for electrochemical sensor materials. However, when utilized as electrode materials for electrochemical sensor configurations, MOFs present several drawbacks, including low electrocatalytic activity, poor electronic conductivity, and reduced mechanical strength. These drawbacks limit the sensitivity and stability of MOF-based electrochemical sensors. Therefore, improving the stability and electrical conductivity of MOFs is crucial for expanding their use in electrochemical applications.

[0010] In recent years, several innovative MOF-based composites have been developed for electrochemical sensing applications. Examples include ZnO@ZIF-8 nanocomposites for the selective detection of hydrogen peroxide and ascorbic acid, MOF-derived NiO@ZnO for isoniazid detection, and MOF-derived binary metal oxide NiO@ZnO for rutin detection.

[0011] Graphene (Gr) has attracted significant attention in the field of electrochemical sensors due to its excellent physical and chemical properties, including a large surface area, excellent electrical conductivity, and strong electrocatalytic activity. In graphene-based MOF hybrids, graphene not only enhances the electrical conductivity and mechanical strength, but also significantly improves the stability and electrochemical catalytic activity of the fabricated electrodes. The enhanced electrochemical performance of the MOFs@Gr hybrids is due to the synergistic activity of the active moieties. Furthermore, the stacking interaction between the imidazole groups of the ð-ð MOF and the graphene ligands is known to enhance electron mobility by delocalizing electrons throughout the entire conjugated complex.

[0012] In this way, research on new electrochemical sensor technologies using pn heterojunctions and graphene, product development, and various studies on the potential applications of manufactured electrochemical sensors are continuously being conducted, and the demand for expansion into new areas is increasing.

[0013] Recently, TMO (transition metal oxide) nanostructures have attracted much attention due to their excellent performance in various fields such as electricity, magnetism, and optics. TMO NPs have many unique features, including a large band gap, favorable electrical properties, high dielectric constant, and reactive electronic transitions. Among various transition metal oxides, cobalt oxide (Co3O4) is a well-known p-type semiconductor with an indirect band gap in the range of 1.6–2.2 eV. It is characterized by the tetrahedral site of Co 2+ The octahedral part is occupied by Co ions 3+ It has a typical AB2O4 cubic backbone structure occupied by Co ions. 2+ Oxygen molecules can be easily adsorbed on the Co3O4 surface because the ions can be easily oxidized to a higher oxidation state.

[0014] Moreover, Co3O4 is Co 2+ / Co 3+Zinc oxide (ZnO) is an interesting material for sensing applications due to its redox behavior. Zinc oxide (ZnO), on the other hand, is an n-type semiconductor oxide material with a wide bandgap of 3.37 eV and a high excitation binding energy of 60 meV. ZnO is environmentally friendly, abundant, and inexpensive to synthesize, and can generate electron-hole pairs when exposed to visible or ultraviolet light. These properties have led to its consideration as a viable electrode material. However, ZnO has several limitations, such as low conductivity and poor stability, which have limited its potential for sensing applications. To overcome these limitations, we attempted to form a pn heterojunction combining ZnO and Co3O4. A pn ​​heterojunction is a junction between two semiconductor materials with different bandgaps. This junction creates a depletion region devoid of free charge carriers. This depletion region can also act as a barrier to charge carrier flow, which could provide excellent sensing capabilities. The combination of ZnO and Co3O4 can enhance the selectivity and conductivity of ZnO. This is because Co3O4 can act as a catalyst for the oxidation of analytes, while ZnO can act as a conductor for electrons generated by the oxidation reaction.

[0015] The present invention utilizes the characteristics of ZnO and Co3O4, which have the above-described properties, as a pn heterojunction composite, and by a simple means called a sonochemical approach, it has been found that when a metal-organic framework (MOF) in which the composite is fixed to graphene is applied to an electrochemical biosensor electrode, the quantitative and / or qualitative detection of alfuzosin is excellent, thereby completing the present invention. That is, the present invention aims to provide a novel metal-organic framework, a working electrode for an electrochemical biosensor using the same, an electrochemical biosensor, and a method for manufacturing the same.

[0016]

[0017] It is hereby disclosed that the present invention was derived with the support of the following national research and development project.

[0018] [National Research and Development Project 1 that supported this invention]

[0019] [Project ID] 1345362911 [Project ID] 2021R1A6A1A03039503

[0020] [Ministry Name] Ministry of Education [Project Management (Specialist) Institution Name] National Research Foundation of Korea

[0021] [Research Project Name] Establishment of a Research Base for Science and Engineering

[0022] [Research Project Name] Korea Native Animal Resources Convergence Research Institute

[0023] [Contribution rate] 40 / 100 [Name of project performing organization] Soonchunhyang University

[0024] Research Period: June 1, 2021 - December 31, 2030

[0025]

[0026] [National Research and Development Project 2 that supported this invention]

[0027] [Project ID]1485019375 [Project ID]ARQ201902181005

[0028] [Ministry Name] Ministry of Environment [Project Management (Specialist) Organization Name] Korea Environmental Industry & Technology Institute

[0029] [Research Project Name] Development of Eco-inspired Environmental Pollution Management Technology

[0030] [Research Project Name] Biomimetic Technology-Based Peptide Acquisition for the Detection of Environmental Hormones

[0031] Development of body synthesis and portable measuring devices

[0032] [Contribution rate] 30 / 100 [Name of project performing organization] G&C Bio Co., Ltd.

[0033] Research Period: April 17, 2019 - December 31, 2023

[0034]

[0035] [National Research and Development Project 3 that supported this invention]

[0036] [Project ID] 1711181666 [Project ID] 2020R1A2C1014918

[0037] [Ministry Name] Ministry of Science and ICT

[0038] [Name of Project Management (Specialist) Institution] National Research Foundation of Korea

[0039] [Research Project Name] Individual Basic Research (Ministry of Science and ICT)

[0040] [Research Project Name] MoS2 Transistor-Based Myocardial Infarction Using Biomimetic Technology

[0041] Development of diagnostic biosensors

[0042] [Contribution rate] 30 / 100 [Name of project performing organization] Soonchunhyang University

[0043] [Research Period] March 1, 2020 - February 28, 2025

[0044] In order to solve the above-described problem, the present invention is a metal-organic framework for an electrochemical biosensor electrode, which is an electrochemical biosensor electrode material for detecting alfuzosin, and is a binary metal-organic framework (ZnO / Co3O4@Gr) in which a ZnO / Co3O4 nanocomposite in which ZnO and Co3O4 are bonded to graphene is fixed.

[0045] As a preferred embodiment of the present invention, the ZnO / Co3O4 nanocomposite is included in an amount of 50 to 150 parts by weight per 100 parts by weight of the graphene.

[0046] As a preferred embodiment of the present invention, the ZnO / Co3O4 nanocomposite contains 8.00 to 11.50 atom% of cobalt (Co), 29.00 to 32.00 atom% of zinc (Zn), and the remaining balance of 100 atom% of oxygen (O).

[0047] As a preferred embodiment of the present invention, the binary metal-organic framework comprises 3.20 to 5.00 atom% of cobalt (Co), 6.00 to 8.00 atom% of zinc (Zn), 23.0 to 25.20 atom% of oxygen (O), and the remainder of 100 atom% of carbon (C).

[0048] Another object of the present invention relates to a method for producing the metal-organic framework, comprising: a first step of preparing ZIF-Zn; a second step of adding ZIF-Zn to a cobalt supply solution in which cobalt nitrate hexahydrate is dissolved in methanol, and then a 2-MIM (methylimidazole) solution is added dropwise and stirred to precipitate the mixture, followed by filtering to obtain a solid; a third step of washing the solid and drying it at 75 to 90°C to obtain a bimetallic ZIF (zeolitic imidazole framework)-ZnCo; a fourth step of calcining the bimetallic ZIF-ZnCo to produce a ZnO / Co3O4 nanocomposite in which ZnO and Co3O4 are combined; a fifth step of adding graphene to ethanol and ultrasonicating it to produce a graphene dispersion, and then centrifuging to collect the graphene; A process is performed to manufacture the graphene composite (ZnO / Co3O4@Gr) by performing a 6-step process of preparing a diluted solution by diluting the collected graphene in ethanol, adding the ZnO / Co3O4 nanocomposite to the diluted solution, performing ultrasonic treatment, and then centrifuging to obtain a graphene composite (ZnO / Co3O4@Gr) with the ZnO / Co3O4 nanocomposite fixed thereon; and a 7-step process of washing and then drying the obtained graphene composite with the ZnO / Co3O4 nanocomposite fixed thereon.

[0049] As a preferred embodiment of the present invention, the cobalt supply solution of step 2 may contain 1.20 to 2.00 mmol of cobalt nitrate hexahydrate per 40 ml of methanol, and the 2-MIM solution may contain 13.00 to 18.00 mmol of 2-MIM per 40 ml of methanol.

[0050] As a preferred embodiment of the present invention, the amount of ZIF-Zn added in the second step may be 0.15 to 0.40 g of ZIF-Zn per 40 ml of cobalt supply solution.

[0051] As a preferred embodiment of the present invention, the two-step co-precipitation can be performed by leaving it at 10 to 35°C for 20 to 48 hours.

[0052] As a preferred embodiment of the present invention, the bimetallic ZIF-ZnCo of the third step may include 28.00 to 32.00 atom% of nitrogen (N), 0.40 to 0.75 atom% of cobalt (Co), 1.00 to 1.35 atom% of zinc (Zn), and the remaining balance of 100 atom% of carbon (C).

[0053] As a preferred embodiment of the present invention, the ZnO / Co3O4 nanocomposite of the fourth step may include 8.00 to 11.50 atom% of cobalt (Co), 29.00 to 32.00 atom% of zinc (Zn), and the remaining balance of 100 atom% of oxygen (O).

[0054] As a preferred embodiment of the present invention, the five-step graphene dispersion may contain 5 to 15 mg of graphene per 10 ml of ethanol.

[0055] As a preferred embodiment of the present invention, step 6 may be performed by preparing a diluted solution by diluting 5 to 15 mg of the collected graphene per 10 ml of ethanol, then adding 5 to 15 mg of the ZnO / Co3O4 nanocomposite per 10 ml of the diluted solution, and then performing ultrasonic treatment.

[0056] As a preferred embodiment of the present invention, the four-step firing can be performed at 380 to 450°C for 1.5 to 3.0 hours.

[0057] As a preferred embodiment of the present invention, the drying in the third step may be performed at 70 to 90°C for 8 to 20 hours, and the drying in the seventh step may be performed at 70 to 90°C for 4 to 6 hours.

[0058] Another object of the present invention relates to a working electrode for an electrochemical biosensor, comprising the metal-organic framework described above.

[0059] As a preferred embodiment of the present invention, the working electrode may be a glassy carbon electrode modified with the metal-organic framework.

[0060] In addition, the present invention relates to a method for manufacturing a working electrode for the electrochemical biosensor, which can be manufactured by performing a process including: a first step of manufacturing a dispersion liquid by mixing methanol and the metal-organic framework; and a second step of coating the dispersion liquid on the surface of a glassy carbon electrode and then drying it by irradiating it with infrared rays.

[0061] As a preferred embodiment of the present invention, the dispersion in step 1 can be prepared by adding 0.5 to 1.5 mg of the metal-organic framework per 1 ml of methanol and then homogenizing it through ultrasonic treatment.

[0062] In addition, another object of the present invention relates to an electrochemical biosensor, which is an electrochemical biosensor equipped with the working electrodes, and is a non-enzymatic electrochemical sensor used for quantitative and qualitative detection of alfuzosin.

[0063]

[0064] The electrochemical biosensor based on the metal-organic framework (ZnO / Co3O4@Gr nanocomposite) of the present invention has a linear range from 0.05 μM to 40 μM, a very low detection limit (0.004 μM), a high detection range, and excellent selectivity, reproducibility, and stability. The electrochemical biosensor of the present invention enables simple and rapid quantitative and / or qualitative analysis of alfuzosin, which is used to improve symptoms of benign prostatic hyperplasia, as well as other biomaterials.

[0065] FIG. 1 is a schematic process diagram for a ZnO / Co3O4 nanocomposite of the present invention and a schematic process diagram for ZnO / Co3O4@Gr, as a preferred example.

[0066] Figure 2a is a graph of XRD patterns measured for ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo.

[0067] Figure 2b is a graph of ATR-IR spectra measurements for ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo.

[0068] Figure 2c shows the results of ATR-IR (Attenuated total reflectance infrared) measurements for 2-MIM, ZIF-Co, ZIF-Zn, and bimetallic ZIF-ZnCo, ZnO, Co3O4, ZnO / Co3O4, and ZnO / Co3O4@Gr.

[0069] Figure 2d shows (a) to (c) FE-SEM images of ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo, respectively, (d) to (f) EDS spectrum measurement results of ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo, respectively, and (g) to (k) EDS mapping analysis results.

[0070] Figure 2e shows the EDS mapping and spectrum measurement results, where (a) to (c) are the measurement results for ZnO, (d) to (f) are the measurement results for Co3O4, and (g) to (i) are the measurement results for ZnO / Co3O4.

[0071] In Fig. 2f, (a) to (d) are FE-SEM images of ZnO, Co3O4, ZnO / Co3O4, and graphene, respectively; (e) and (f) are FE-SEM images of the ZnO / Co3O4@Gr nanocomposite; (g) is an EDS spectrum of the ZnO / Co3O4@Gr nanocomposite; and (h) to (l) are EDS mapping analysis results.

[0072] Figures 3 (a) to (d) are FE-SEM measurement images of ZnO / Co3O4@Gr nanocomposites, (e) is an FE-TEM measurement image, and (g) to (k) are EDS mapping analysis results.

[0073] Figure 4 shows the results of EIS (electrochemical impedance spectroscopy) measurements for each of Manufacturing Example 1 (ZnO / Co3O4@Gr / GCE), Gr / GCE (Comparative Manufacturing Example 1), ZnO / GCE (Comparative Manufacturing Example 2), Co3O4 / GCE (Comparative Manufacturing Example 3), and ZnO / Co3O4 / GCE (Comparative Manufacturing Example 4) performed in Experimental Example 5.

[0074] Figure 5 shows the results of measuring the electrochemical performance of alfuzosin (AFZ) of the ZnO / Co3O4@Gr / GCE working electrode of Manufacturing Example 1 conducted in Experimental Example 6.

[0075] Figure 6 shows the results of measuring the electrical performance of alfuzosin (AFZ) as an electrochemical biosensor in Experimental Example 7.

[0076] Figure 7 compares the AFZ detection limit of a biosensor for AFZ detection using ZnO / Co3O4@Gr / GCE of the present invention as a working electrode and a previously reported comparative AFZ sensor.

[0077] Figure 8 shows the results of an experiment to evaluate the detection stability and reproducibility of an electrochemical biosensor for detecting alfuzosin (AFZ) conducted in Experimental Example 8.

[0078] Figure 9 is an evaluation data of actual application of AFZ detection of a biosensor using ZnO / Co3O4@Gr / GCE of Manufacturing Example 1 performed in Experimental Example 9, where (a) is DPV curve data for an AFZ-containing pharmaceutical tablet sample, (c) is a urine sample, and (e) is DPV curve data for human serum without AFZ.

[0079] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0080] The metal-organic framework for an electrochemical biosensor electrode of the present invention is a binary metal-organic framework (ZnO / Co3O4@Gr) in which a ZnO / Co3O4 nanocomposite in which ZnO and Co3O4 are bonded to graphene is fixed, as an electrochemical biosensor electrode material for detecting alfuzosin.

[0081] The above ZnO / Co3O4@Gr contains 50 to 150 parts by weight of the ZnO / Co3O4 nanocomposite, preferably 80 to 135 parts by weight, and more preferably 90 to 120 parts by weight, based on 100 parts by weight of the graphene. At this time, if the content of the ZnO / Co3O4 nanocomposite is less than 50 parts by weight, there may be a problem that the detection sensitivity for the analyte as a biosensing may be significantly reduced, and if it exceeds 150 parts by weight, it is uneconomical and, rather, there may be a problem that the detection sensitivity may be reduced due to excessive use.

[0082] The metal-organic framework of the present invention is manufactured by synthesizing a bimetallic ZIF (Zeolitic imidazole framework)-ZnCo based on zinc and cobalt, then sintering it to manufacture a ZnO / Co3O4 nanocomposite, and then fixing it to graphene.

[0083] To explain more specifically, it can be manufactured by the method shown in the schematic process diagrams A and B of Fig. 1, and this is explained as follows.

[0084] Step 1 of preparing ZIF-Zn (or ZIF-8); Step 2 of adding ZIF-Zn to a cobalt supply solution containing cobalt nitrate hexahydrate (Co(NO3)2·6H2O) dissolved in methanol, and then adding 2-MIM (methylimidazole) solution dropwise and stirring the mixture to precipitate, and then filtering to obtain a solid; Step 3 of washing the solid and then drying it to obtain a bimetallic ZIF (zeolitic imidazole framework)-ZnCo; Step 4 of calcining the bimetallic ZIF-ZnCo to produce a ZnO / Co3O4 nanocomposite in which ZnO and Co3O4 are combined; Step 5 of adding graphene to ethanol and ultrasonicating it to produce a graphene dispersion, and then centrifuging it to collect the graphene; A process is performed to manufacture the graphene composite (ZnO / Co3O4@Gr) by performing a 6-step process of preparing a diluted solution by diluting the collected graphene in ethanol, adding the ZnO / Co3O4 nanocomposite to the diluted solution, performing ultrasonic treatment, and then centrifuging to obtain a graphene composite (ZnO / Co3O4@Gr) with the ZnO / Co3O4 nanocomposite fixed thereon; and a 7-step process of washing and then drying the obtained graphene composite with the ZnO / Co3O4 nanocomposite fixed thereon.

[0085] Each of the ZIF-Zn and ZIF-Co in step 1 can be commercially available or directly synthesized. As an example of direct synthesis, the ZIF-Zn in step 1 can be prepared by adding a 2-MIM (methylimidazole) solution dropwise to a solution containing 1.60 to 2.40 mmol, preferably 1.80 to 2.20 mmol, more preferably 1.90 to 2.10 mmol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) per 40 mL of methanol, followed by coprecipitation at room temperature (10 to 35°C) for 20 to 36 hours, centrifugation, washing with methanol several times, and drying. At this time, the 2-MIM solution may contain 1.20 to 1.80 mmol of 2-MIM per 40 mL of methanol, preferably 1.40 to 1.75 mmol, more preferably 1.50 to 1.65 mmol.

[0086] Next, the cobalt supply solution of step 2 may contain 1.20 to 2.00 mmol of cobalt nitrate hexahydrate per 40 ml of methanol, and the 2-MIM solution may contain 13.00 to 18.00 mmol of 2-MIM per 40 ml of methanol. At this time, if the cobalt nitrate hexahydrate in the cobalt supply solution is 1.20 mmol, the content thereof may be too little, so that the Co3O4 content in the synthesized ZnO / Co3O4 nanocomposite may be relatively too low, which may cause a problem in that the biosensing performance may be reduced. In addition, if the cobalt nitrate hexahydrate is used in excess of 2.00 mmol, the amount of cobalt nitrate remaining after the reaction may be excessive because the concentration is already excessive. Therefore, it is appropriate to use it in a concentration within the above range.

[0087] And, in terms of obtaining an appropriate amount of solid, it is advantageous to add 0.15 to 0.40 g of ZIF-Zn, preferably 0.18 to 0.32 g, and more preferably 0.18 to 0.25 g of ZIF-Zn per 40 ml of cobalt supply solution in the second step.

[0088] And, the 2-MIM solution of step 2 may contain 1.20 to 1.80 mmol of 2-MIM per 40 mL of methanol, preferably 1.40 to 1.75 mmol, more preferably 1.50 to 1.65 mmol. At this time, if the 2-MIM content in the 2-MIM solution is less than 1.20 mmol, there may be a problem of too little coprecipitation amount, and using more than 1.80 mmol is excessive use, and rather, it is uneconomical because a large amount of unreacted substances is generated.

[0089] And, the second stage of co-precipitation can be performed by leaving it at 10 to 35℃ for 20 to 48 hours, and preferably by leaving it at 15 to 30℃ for 20 to 28 hours.

[0090] In addition, the second stage of filtration can be performed without limitation using common filtration methods used in the industry, such as centrifugation and vacuum filtration.

[0091] Next, the third step is a process of obtaining a bimetallic ZIF (Zeolitic imidazole framework)-ZnCo by washing the solid obtained in the second step several times with methanol and then drying it. At this time, the drying method is not particularly limited, and a preferred example is vacuum drying at 75 to 90°C, preferably at 75 to 85°C, for about 8 to 20 hours.

[0092] The bimetallic ZIF-ZnCo manufactured in this manner may contain nitrogen (N) 28.00 to 32.00 atom%, cobalt (Co) 0.40 to 0.75 atom%, zinc (Zn) 1.00 to 1.35 atom% and carbon (C) remaining among 100 atom%, preferably nitrogen (N) 28.50 to 31.50 atom%, cobalt (Co) 0.42 to 0.70 atom%, zinc (Zn) 1.10 to 1.35 atom% and carbon (C) remaining among 100 atom%, more preferably nitrogen (N) 28.80 to 31.00 atom%, cobalt (Co) 0.44 to 0.65 atom%, zinc (Zn) 1.12 to 1.33 It may contain the remaining carbon (C) of 100 atom% and 100 atom%.

[0093] Next, the fourth step is a process of performing sintering to transform the bimetallic ZIF-ZnCo into a porous ZnO / Co3O4 nanocomposite in which ZnO and Co3O4 are combined through the Kirkendall effect. At this time, the sintering is suitably performed at 380 to 450°C for 1.5 to 3.0 hours, preferably at 380 to 430°C for 1.5 to 3.0 hours. If the sintering temperature exceeds 450°C, there may be a problem in that the ZnO and Co3O4 aggregate, resulting in a significant deterioration in the sensing characteristics. Therefore, it is suitably performed to perform the sintering within the above temperature range.

[0094] The four-step ZnO / Co3O4 nanocomposite manufactured through sintering may contain 8.00 to 11.50 atom% of cobalt (Co), 29.00 to 32.00 atom% of zinc (Zn), and the remaining amount of oxygen (O) among 100 atom%, preferably 8.50 to 11.00 atom% of cobalt (Co), 29.10 to 31.50 atom% of zinc (Zn), and the remaining amount of oxygen (O) among 100 atom%, and more preferably 9.00 to 11.00 atom% of cobalt (Co), 29.20 to 31.20 atom% of zinc (Zn), and the remaining amount of oxygen (O) among 100 atom%.

[0095] Next, the graphene dispersion of step 5 may contain 5 to 15 mg of graphene per 10 ml of ethanol, preferably 8.5 to 13.0 mg of graphene, more preferably 9.0 to 12.0 mg of graphene. At this time, if the graphene content is less than 5 mg, the amount used is too small, which may cause poor electrical properties of ZnO / Co3O4@Gr, resulting in a problem of insufficient detection sensitivity, and if it exceeds 15 mg, it is uneconomical.

[0096] And, the 5-step ultrasonic treatment can be performed for 20 to 60 minutes under an ultrasonic intensity of 35 to 50 kHz, preferably for 20 to 40 minutes under an ultrasonic intensity of 37 to 45 kHz.

[0097] Next, step 6 is a process for manufacturing a graphene composite (ZnO / Co3O4@Gr) with a ZnO / Co3O4 nanocomposite fixed thereto. After preparing a diluted solution by diluting the collected graphene in ethanol, the ZnO / Co3O4 nanocomposite is added to the diluted solution, followed by ultrasonic treatment and centrifugation.

[0098] The above diluted solution may contain 5 to 15 mg of collected graphene per 10 ml of ethanol, preferably 8.5 to 13.0 mg of graphene, and more preferably 9.0 to 12.0 mg of graphene.

[0099] And, 5 to 15 mg of the ZnO / Co3O4 nanocomposite, preferably 8.5 to 12.0 mg, more preferably 9.0 to 11.5 mg, is added per 10 ml of the diluted solution, and then ultrasonic treatment can be performed.

[0100] At this time, the above-mentioned 6-step ultrasonic treatment can be performed for 20 to 60 minutes under an ultrasonic intensity of 35 to 50 kHz, preferably for 20 to 40 minutes under an ultrasonic intensity of 37 to 45 kHz.

[0101] Next, in step 7, the graphene composite with the ZnO / Co3O4 nanocomposite fixed thereon obtained in step 6 is washed, and then vacuum dried at 75 to 90°C, preferably at 75 to 85°C, for about 4 to 6 hours to finally obtain a binary metal-organic framework (ZnO / Co3O4@Gr) with the ZnO / Co3O4 nanocomposite fixed thereon, in which ZnO and Co3O4 are combined.

[0102] The binary metal-organic framework manufactured in this way may include cobalt (Co) 3.20 to 5.00 atom%, zinc (Zn) 6.00 to 8.00 atom%, oxygen (O) 23.0 to 25.20 atom% and the remaining amount of carbon (C) among 100 atom%, preferably cobalt (Co) 3.50 to 4.70 atom%, zinc (Zn) 6.30 to 7.80 atom%, oxygen (O) 23.20 to 25.00 atom% and the remaining amount of carbon (C) among 100 atom%, more preferably cobalt (Co) 3.75 to 4.50 atom%, zinc (Zn) 6.50 to 7.50 atom%, oxygen (O) 23.60 to 24.65 atom% and may contain the remaining amount of carbon (C) among 100 atom%.

[0103]

[0104] The metal-organic framework of the present invention described above can be used as an electrochemical biosensor electrode, preferably by modifying a glassy carbon electrode and applying it as a working electrode.

[0105] For example, in a preferred embodiment, a working electrode for an electrochemical biosensor can be manufactured by performing a process including: a first step of preparing a dispersion by mixing methanol and the metal-organic framework; and a second step of coating the dispersion on the surface of a glassy carbon electrode and then drying it by irradiating it with infrared rays.

[0106] In step 1, the dispersion can be prepared by adding 0.5 to 1.5 mg of the metal-organic framework, preferably 0.8 to 1.3 mg, per 1 ml of methanol, and then homogenizing through ultrasonic treatment.

[0107] In addition, the electrochemical biosensor equipped with the above working electrodes is suitable for application as a non-enzymatic electrochemical sensor used for quantitative and qualitative detection of Alfuzosin used for improving symptoms of benign prostatic hyperplasia, and is capable of simple and rapid quantitative and / or qualitative analysis of other biomaterials.

[0108]

[0109] The present invention will be described in more detail through the following examples, but the following examples do not limit the scope of the present invention, and should be interpreted as helping to understand the present invention.

[0110] [Example]

[0111] Preparation Example 1: Synthesis of ZIF (Zeolitic imidazole framework)-Zn and ZnO

[0112] (1) ZIF-Zn (ZIF-8) synthesis

[0113] A solution of 1.98 mmol of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 40 mL of methanol was sonicated and then magnetically stirred to prepare a transparent solution. Then, after stirring for 30 minutes, a transparent 2-MIM (methylimidazole) solution was slowly added dropwise to the solution. Then, the mixture was statically allowed to stand at 20 to 25°C for 24 hours to coprecipitate the reaction product, a precipitate. At this time, the 2-MIM solution was prepared by mixing 15.83 mmol of 2-MIM and 40 mL of methanol.

[0114] Next, the reaction product mixture was centrifuged, washed several times with methanol, and vacuum dried at 80°C for 12 hours, and the final reaction product obtained was ZIF-Zn (ZIF-8).

[0115] (2) ZnO manufacturing

[0116] Next, the obtained ZIF-Zn (ZIF-8) was heated to 400°C in air at a heating rate of 2°C / min, and a calcination process was performed at this temperature for 2 hours to obtain ZnO.

[0117]

[0118] Preparation Example 2: Synthesis of ZIF-Co

[0119] (1) Manufacturing of ZIF-Co (ZIF-67)

[0120] A solution containing 1.68 mmol of cobalt zinc hexahydrate (Co(NO3)2·6H2O) and 40 mL of methanol was sonicated and then magnetically stirred to prepare a transparent solution. After stirring for 30 minutes, a transparent 2-MIM solution was slowly added dropwise to the solution. Subsequently, the mixture was allowed to stand statically at 20 to 25°C for 24 hours to precipitate the reaction product, a precipitate. At this time, the 2-MIM solution was prepared by mixing 15.83 mmol of 2-MIM and 40 mL of methanol.

[0121] Next, the reaction product mixture was centrifuged and washed several times with methanol, and then vacuum dried at 80°C for 12 hours. The final reaction product obtained was ZIF-Co (ZIF-67).

[0122] (2) Co3O4 manufacturing

[0123] Next, the obtained ZIF-Co (ZIF-67) was heated to 400°C in air at a heating rate of 2°C / min, and a calcination process was performed at this temperature for 2 hours to obtain Co3O4.

[0124]

[0125] Example 1: Synthesis of ZnO / Co3O4@Gr nanocomposite (metal-organic framework)

[0126] (1) Preparation of bimetallic ZIF-ZnCo and ZnO / Co3O4 nanocomposites

[0127] A solution containing 1.68 mmol of cobalt zinc hexahydrate (Co(NO3)2·6H2O) and 40 mL of methanol was sonicated and then magnetically stirred to prepare a transparent cobalt source solution.

[0128] Next, 0.2 g of ZIF-Zn prepared in Preparation Example 1 was added to the cobalt source solution while stirring vigorously. Subsequently, the 2-MIM solution was added dropwise to the ZIF-Zn solution, and stirring was continued. At this time, the 2-MIM solution was prepared by mixing 15.83 mmol of 2-MIM and 40 mL of methanol.

[0129] Then, the mixture was left statically at room temperature (23-25℃) for 24 hours to perform coprecipitation.

[0130] Next, centrifugation was performed at 5000 rpm for 15 minutes, and the obtained solid was washed several times with methanol and then vacuum dried overnight at 80°C to obtain bimetallic ZIF-ZnCo.

[0131] Next, the obtained bimetallic ZIF-ZnCo was heated to 400°C in air at a heating rate of 2°C / min, and a calcination process was performed at this temperature for 2 hours to obtain a ZnO / Co3O4 nanocomposite.

[0132] (2) Preparation of ZnO / Co3O4@Gr nanocomposite

[0133] After mixing 10 mg of graphene (Gr) per 10 ml of ethanol, the mixture was dispersed in ethanol through ultrasonic treatment at room temperature for 30 minutes to prepare a graphene dispersion, which was then centrifuged at 5000 rpm for 15 minutes to collect graphene.

[0134] Next, the collected graphene was mixed with ethanol to prepare a diluted solution of 10 mg / ml of graphene, and then 10 mg of the previously prepared ZnO / Co3O4 nanocomposite was added per 10 ml of the diluted solution, followed by ultrasonic treatment, and then centrifugation was performed at 5000 rpm for 15 minutes.

[0135] Next, a graphene composite (ZnO / Co3O4@Gr) with ZnO / Co3O4 nanocomposite fixed thereon was prepared by drying at 80°C for 5 hours.

[0136]

[0137] Experimental Example 1: XRD (X-ray diffraction) and XPS (X-ray photoelectron spectroscopy) measurements

[0138] (1) XRD measurement graphs for each of ZIF-Zn manufactured in Preparation Example 1, ZIF-Co manufactured in Preparation Example 2, and bimetallic ZIF-ZnCo manufactured in Example 1 are shown in Fig. 2a.

[0139] As shown in Fig. 2a, the XRD patterns of the ZIF-Zn and ZIF-Co crystals exhibited diffraction peaks at 7.43°, 10.42°, 12.79°, 14.75°, 16.50°, 18.11°, 22.18°, 24.56°, and 26.75°, with no additional peaks. These peaks correspond to the (011), (002), (112), (022), (013), (222), (114), (233), and (134) planes, respectively. It can be confirmed that these peaks are observed in the diffraction peaks of the bimetallic ZIF-ZnCo, suggesting that the unique framework structure of the parent ZIF was maintained throughout the composite formation. Moreover, there was no separation of ZIF-Zn and ZIF-Co crystals in the diffraction peaks of bimetallic ZIF-ZnCo, indicating that Zn in tetrahedral coordination 2+ and Co 2+Because the ionic radii of Co are similar (0.74 A° and 0.72 A°, respectively), 2+ The ion is Zn 2+ Allows ions to be replaced.

[0140] (2) The XRD measurement results for each of graphene (Gr), ZnO prepared in Preparation Example 1, Co3O4 prepared in Preparation Example 2, and ZnO / Co3O4 and ZnO / Co3O4@Gr nanocomposites prepared in Example 1 are shown in (a) of Fig. 2b.

[0141] The XRD spectrum of graphene (Gr) showed diffraction peaks at 25.5° and 43° corresponding to the (002) and (101) planes, respectively, indicating that graphene (Gr) is in a graphitic state. In addition, the ZnO diffraction peaks at 31.70°, 34.25°, 36.09°, 47.35°, 56.49°, 62.78°, and 67.76° correspond to the (100), (002), (101), (102), (110), (103), and (112) ZnO planes (JCPDS card 36-1451). And, Co3O4 diffraction peaks at 19.14°, 31.37°, 36.92°, 44.90°, 59.50°, and 65.30° correspond to Co3O4 planes of (111), (220), (311), (400), (511), and (440) (JCPDS card 65-3103).

[0142] In the XRD characterization of ZnO / Co3O4, no characteristic peaks for ZnO or Co3O4 were found, and no impurity peaks were present. This indicates that the precursors ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo were completely converted to ZnO and Co3O4. The faint pattern at about 2θ=25.5° in the XRD patterns of ZnO / Co3O4 and ZnO / Co3O4@Gr nanocomposites indicates the presence of carbon.

[0143] The fact that the diffraction peaks of other components remain in the same direction even after adding graphene indicates that the addition of graphene did not significantly change the crystal structure of the nanocomposite.

[0144] (3) XPS analysis of ZnO / Co3O4@Gr nanocomposites

[0145] Figures 2b (b) to (f) are XPS analysis spectra of the ZnO / Co3O4@Gr nanocomposite covering the entire investigation scanning range.

[0146] The spectrum (b) of Fig. 2b shows the presence of Co, Zn, O, and C, which are the chemical components of the nanocomposite. No additional elements were detected, indicating the high purity of the sample, consistent with the XRD analysis. The high-resolution XPS spectrum of Co 2p ((c) of Fig. 2b) shows that Co 2p 3 / 2 and Co 2p 1 / 2 Two prominent peaks were observed at binding energies of 780.41 eV and 795.75 eV, corresponding to the peak of Co 2p. 3 / 2 Wow Co 2p 1 / 2 The spin energy separation between the peaks was 15.35 eV, which corresponds to Co in the composite. 3+ Wow Co 2+ It confirms the presence of Co3O4 in the composite. Further confirmation of the presence of Co3O4 in the composite is Co 3+ (Co 2p 3 / 2 At the strong peak of Co 2+ (780.27 eV) and Co2+(781.21 eV) exist, and Co 2p 1 / 2 Each shoulder peak of Co 3+ (795.18 eV) and Co2+ (796.90 eV) were present.

[0147] Co 2p each 3 / 2 and Co 2p 1 / 2 Two faint wobble satellite peaks with binding energies of 789.17 eV and 804.40 eV corresponding to the peak were also observed.

[0148] As shown in (d) of Fig. 2b, the high-resolution XPS spectrum of Zn 2p is Zn 2p 3 / 2 and Zn 2p 1 / 2 It shows two different peaks at binding energies 1022.67 eV and 1045.77 eV, which are attributed to two energy levels (Zn 2p 3 / 2 and Zn 2p 1 / 2 ) has a spin-orbit splitting of 23.1 eV, which is close to the spin-orbit splitting of the prepared nanocomposite. 2+ It means that exists.

[0149] As shown in (e) of Fig. 2b, the O 1s high-resolution XPS spectrum shows the presence of O 1 , O 2 , and O 3 with binding energies of 530.17 eV, 531.73 eV, and 533.14 eV, respectively. This is due to the Co-O, Zn-O, and HOH bonds of the surface hydroxide.

[0150] As seen in (f) of Fig. 2b, the C 1s peak of the high-resolution XPS spectrum contains sp 2 It contains three Gaussian peaks at binding energies of 284.77 eV, 286.34 eV and 288.71 eV, which are attributed to hybridized CC / C=C, C-O-C and C=O.

[0151] Table 1 summarizes the XPS data of ZnO / Co3O4@Gr nanocomposites.

[0152] Chemical element peak deconvolution binding energy (eV) interaction and oxidation state Zn 2pZn 2p 3 / 2 1022.67Zn 2+ Zn 2p 1 / 2 1045.77Co 2pCo 2p 3 / 2 780.41Co 3+ and Co 2+ 780.27781.21Co 2p 1 / 2 795.75795.18796.90O 1s-530.17Co-O531.73Zn-O533.14H-O-HC 1s-284.77CC / C=C(sp 2hybridized)286.34CO-C288.71C=O

[0153]

[0154] Experimental Example 2: ATR-IR Spectrum Measurement

[0155] Structural analysis of 2-MIM ligand, ZIF-Co, ZIF-Zn, bimetallic ZIF-ZnCo, ZnO, Co3O4, ZnO / Co3O4, and ZnO / Co3O4@Gr nanocomposites was performed using ATR-IR (Attenuated total reflectance infrared), and the results are shown in Fig. 2c.

[0156] Figure 2c (a) shows the spectra of 2-MIM ligand, ZIF-Co, ZIF-Zn, and bimetallic ZIF-ZnCo, confirming the bonding between organic ligand and metal. 2300–3100 cm -1 A single peak at 1835 cm indicates NHN bonding. -1 NH stretching was observed in ZIF-Zn, ZIF-Co, and ZIF-ZnCo. However, the aforementioned peaks disappeared in ZIF-Zn, ZIF-Co, and ZIF-ZnCo, indicating that the NH group of the 2-MIM ligand is Co. 2+ / Zn 2+ Because it is deprotonated by interaction with ions. And, Peak 1573 cm indicating stretching -1 , 755 cm -1 This was confirmed, and the M(metal)-N(nitrogen)-M stretching is 424 cm -1 A new adsorption peak was observed, confirming the formation of ZIF.

[0157] Figure 2c (b) shows the results of measuring the metal clusters and organic linkers through ATR-IR. Comparing Figure 2c (a) and (b), it can be seen that after all ZIFs were sintered, these strong and weak peaks all disappeared, suggesting that metal oxide heterogeneous nanostructures were developed.

[0158] Looking at (b) of Fig. 2c, 526 cm -1 Zn-O stretching was confirmed at 554 cm -1 and 662 cm -1 Co-O stretching was confirmed in the peak. The aforementioned data were also confirmed in the spectrum of the ZnO / Co3O4@Gr nanocomposite, and it was confirmed that ZIF-ZnO and ZIF-Co3O4 peaks were present in the ZnO / Co3O4@Gr nanocomposite. However, the addition of graphene did not affect the peak of the ZnO / Co3O4@Gr nanocomposite.

[0159]

[0160] Experimental Example 3: FE-SEM and EDS Analysis

[0161] (1) Analysis of ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo

[0162] The results of field emission scanning electron microscopy (FE-SEM) measurement and EDS spectrum measurement for ZIF-Zn synthesized in Preparation Example 1 are shown in (a) and (d) of Fig. 2d.

[0163] In addition, the FE-SEM measurement and EDS spectrum measurement results for ZIF-Co synthesized in Preparation Example 2 are shown in (b) and (e) of Fig. 2d.

[0164] In addition, FE-SEM measurement images of the bimetallic ZIF-ZnCo synthesized in Example 1 are shown in (c) and (f) of Fig. 2d, and EDS mapping analysis results thereof are shown in (g) to (k).

[0165] FE-SEM measurements revealed that the synthesized MOFs, such as ZIF-Zn and ZIF-Co, exhibited a rhombic dodecahedral morphology with a smooth surface, consistent with previous literature.

[0166] The surface morphology of the bimetallic ZIF-ZnCo changed from a smooth surface to a rough surface, and a minimum of large-sized ZIF-Co particles were formed on the surface of ZIF-Zn, indicating successful composite formation. In addition, EDS mapping confirmed that each element was contained within the bimetallic ZIF-ZnCo, and through this, it was confirmed that ZIF-Zn and ZIF-Co were formed within the bimetallic ZIF-ZnCo.

[0167] (2) Analysis of ZnO, Co3O4, and ZnO / Co3O4EDS

[0168] The EDS mapping and spectrum measurement results for ZnO of Preparation Example 1, Co3O4 of Preparation Example 2, and ZnO / Co3O4 of Example 1 are shown in Fig. 2e, where (a) to (c) are the measurement results for ZnO, (d) to (f) are the measurement results for Co3O4, and (g) to (i) are the measurement results for ZnO / Co3O4.

[0169] Comparing Fig. 2d and Fig. 2e, it was confirmed that ZIF-Zn, ZIF-Co, and bimetallic ZIF-ZnCo were oxidized to ZnO, Co3O4, and ZnO / Co3O4, respectively, by sintering.

[0170] (3) Analysis of ZnO, Co3O4, ZnO / Co3O4, and ZnO / Co3O4@Gr

[0171] In addition, FE-SEM measurement images for ZnO of Preparation Example 1, Co3O4 of Preparation Example 2, and ZnO / Co3O4 and graphene of Example 1 are shown in (a) to (d) in Fig. 2f. (e) and (f) are FE-SEM images of the ZnO / Co3O4@Gr nanocomposite of Example 1.

[0172] Comparing Fig. 2d and Fig. 2f, it can be confirmed that the surface morphology of ZIF-Zn, ZIF-Co, and ZIF-ZnCo changed significantly from smooth to rough and porous after calcination. The MOF-derived ZnO nanomaterials maintained their dodecahedral structure after calcination, but their size tended to become smaller than that of the ZIF-Zn precursor due to decomposition. In addition, the presence of existing elements in ZnO, Co3O4, and ZnO / Co3O4 composites was confirmed through EDS measurement.

[0173] And, (d) of Fig. 2f showed a morphology like a wrinkled and edge-folded graphene sheet, and (e) and (f) of Fig. 2f showed that the regular morphology was destroyed during the synthesis of ZnO / Co3O4@Gr, and the surface of Gr tended to become uneven with smaller ZnO / Co3O4 particles, which means that the ZnO / Co3O4@Gr nanocomposite has a higher surface area than ZIF-Zn, ZIF-Co, ZIF-ZnCo, etc.

[0174] And, (g) of Fig. 2f is the EDS spectrum of the ZnO / Co3O4@Gr nanocomposite, and (h) to (l) show the results of EDS mapping analysis.

[0175] It was confirmed that the ZnO / Co3O4@Gr nanocomposite of Example 1, which is a binary metal-organic framework, contains 4.10 atom% of cobalt (Co), 7.01 atom% of zinc (Zn), 24.27 atom% of oxygen (O), and 100 atom% of carbon (C).

[0176]

[0177] Experimental Example 4: Surface Morphological Investigation of ZnO / Co3O4@Gr Nanocomposite

[0178] Field emission scanning electron microscopy (FE-SEM) images of the ZnO / Co3O4@Gr nanocomposite prepared in Example 1 are shown in Fig. 3 (a) to (d), and field emission transmission electron microscopy (FE-TEM) images are shown in Fig. 3 (e). In addition, the results of selected area electron diffraction (SAED) measurement of the ZnO / Co3O4@Gr nanocomposite are shown in (f), and the results of EDS mapping analysis are shown in (g) to (k) of the analysis of Fig. 3.

[0179] Looking at Fig. 3 (a) to (d), it was clearly confirmed that ultrafine ZnO / Co3O4 particles with small particle sizes existed in the transparent sheet-like structure of graphene. The HR-TEM image in Fig. 3 (e) showed lattice fringes with lattice spacings of 0.217 nm for the (100) crystal plane and 0.283 nm for the (311) crystal plane.

[0180] Additionally, the selected area electron diffraction (SAED) pattern with distinct bright spots in (f) of Fig. 3 indicates the presence of planes (111,)(100),(311),(110), and (112), confirming the polycrystalline nature of the ZnO / Co3O4@Gr nanocomposite.

[0181] Additionally, the element distribution mapping of EDS in Figs. 3 (g) to (k) showed the presence of components in the ZnO / Co3O4@Gr nanocomposite.

[0182]

[0183] Manufacturing Example 1: Manufacturing of a working electrode

[0184] 1 mg of the ZnO / Co3O4@Gr nanocomposite prepared in Example 1 was added to 1 mL of methanol, and then ultrasonicated and stirred to prepare a homogenized dispersion.

[0185] Glassy carbon electrodes (GCE) were sequentially polished with alumina powders of various sizes, including 0.1 μm, 0.3 μm, and 0.05 μm. Next, the GCE was washed several times using deionized water and ethanol by ultrasonication.

[0186] After coating 5 μl of the above dispersion on the surface of the washed GCE, it was dried under an IR lamp to manufacture a GCE working electrode (ZnO / Co3O4@Gr / GCE) modified with a ZnO / Co3O4@Gr nanocomposite.

[0187]

[0188] Comparative manufacturing examples 1 to 4

[0189] Dispersions were prepared in the same manner as in Manufacturing Example 1, but instead of the ZnO / Co3O4@Gr nanocomposite of Example 1, graphene (Gr), ZnO of Preparation Example 1, Co3O4 of Preparation Example 2, and ZnO / Co3O4 of Example 1 were used to prepare dispersions, and then GCE was coated with the dispersion and dried in the same manner to prepare GCE electrodes, Gr / GCE (Comparative Manufacturing Example 1), ZnO / GCE (Comparative Manufacturing Example 2), Co3O4 / GCE (Comparative Manufacturing Example 3), and ZnO / Co3O4 / GCE (Comparative Manufacturing Example 4), respectively.

[0190]

[0191] Experimental Example 5: Electrochemical Performance Measurement

[0192] Electrochemical impedance spectroscopy (EIS) measurements were performed on Manufacturing Example 1 (ZnO / Co3O4@Gr / GCE), Gr / GCE (Comparative Manufacturing Example 1), ZnO / GCE (Comparative Manufacturing Example 2), Co3O4 / GCE (Comparative Manufacturing Example 3), ZnO / Co3O4 / GCE (Comparative Manufacturing Example 4), and the control group (bare GCE), and the results are shown in (a) to (d) of Fig. 4.

[0193] (1) Figure 4 (a) shows the 5 mM [Fe(CN)6] containing 0.1 M KCl using an applied amplitude potential of 0.005 V and a frequency range of 1 Hz to 100 kHz.3- / 4- Here is the result of EIS spectrum measurement. And, the Randles circuit mounted using the data received from EIS measurement is inserted in Fig. 4 (a). Here, R ct represents the charge transfer resistance, R s represents the electrolyte resistance, and Z w represents the Warburg impedance, and C dl represents the double resistance. Each layer capacitance. The diameter of the semicircle shown in the Nyquist plot is R ct This corresponds to a value, which shows that the redox probe electron transfer rate kinetics occur at the electrode / electrolyte interface.

[0194] R of bare GCE (control), ZnO / GCE, Co3O4 / GCE, ZnO / Co3O4 / GCE, Gr / GCE, and ZnO / Co3O4@Gr / GCE ct The values ​​were measured as 619Ω, 921Ω, 837Ω, 717Ω, 465Ω, and 371Ω.

[0195] Pure GCE has lower R than ZnO / GCE, Co3O4 / GCE, and ZnO / Co3O4 / GCE. ct The ZnO / Co3O4 / GCE showed a lower impedance than the GCE. This was due to the electrochemical activity of the solution interface and the GCE surface. However, the ZnO / Co3O4 / GCE had a larger R ct And it exhibited a larger impedance, indicating poor electrical conductivity and a slower electron transfer rate.

[0196] Similarly, ZnO / GCE and Co3O4 / GCE have higher R compared to all other electrodes. ct is larger because the electron transfer between the solution and the electrode surface is slow. And, when Gr is added to the GCE surface, R is higher than that of pure GCE. ct (465Ω) decreases and R is introduced into ZnO / Co3O4 ctThe electrical conductivity was further reduced to 371Ω, and the synergistic effect between Gr and ZnO / Co3O4 significantly increased the electrical conductivity.

[0197] EIS measurement results show that ZnO / Co3O4@Gr / GCE has the lowest R ct The values ​​were achieved, showing appropriate electrical conductivity and fast electron transfer rate.

[0198] (2) 5 mM [Fe(CN)6] containing 0.1 M KCl using cyclic voltammetry (CV) 3- / 4- The electrochemical behavior of the electrode measured in is shown in Fig. 4 (b), which is the measurement result. ZnO / Co3O4@Gr / GCE has a larger peak current response rate (I pa / I pc =15.52μA / 16.19μA) and lower peak-to-peak separation potential (ΔEp = 0.095 V), which is comparable to the redox probe [Fe(CN)6] 3- / 4- It exhibits excellent redox behavior.

[0199] ΔE of Gr / GCE, pure GCE, ZnO / Co3O4 / GCE, Co3O4 / GCE, and ZnO / GCE p The values ​​were 0.105 V, 0.165 V, 0.234 V, 0.309 V, and 0.323 V, respectively. These comparisons indicate that the addition of Gr and ZnO / Co3O4 enhances the feasibility of redox reactions in ZnO / Co3O4@Gr / GCE. These results were confirmed by EIS measurements.

[0200] (3) Figure 4(c) shows the electron transfer kinetics of ZnO / Co3O4@Gr / GCE at various scan rates based on CV analysis. The obtained redox peak current gradually increased with increasing scan rate from 10 mV / s to 100 mV / s, indicating the diffusion-controlled kinetics of the proposed electrode.

[0201] (4) v 1 / 2Peak current (I pa / I pc ) is shown in (d) of Fig. 4.

[0202] The Randles-Sevcik equation (1) was applied to calculate the electrochemically active surface area (EASA) of the electrode.

[0203] [Equation 1]

[0204] I p =(2.69×10 5 )n 3 / 2 D 1 / 2 Av 1 / 2 C

[0205] Here 'I p ' is the peak current (I pa / I pc ) means the rate determining step, 'n' means the number of electrons involved in the rate determining step (n=1), and 'D' means the diffusion coefficient (cm 2 / s) and ' A ' is the active surface area of ​​the electrode (cm 2 ) and 'v' and 'C' represent redox probes [Fe(CN)6] 3- / 4- Scan rate (mV / s) and concentration (mol / cm) 3 ) means.

[0206] The calculated EASA values ​​of ZnO / Co3O4@Gr / GCE, Gr / GCE, ZnO / Co3O4 / GCE, Co3O4 / GCE and ZnO / GCE are 0.41 cm 2 , 0.36 cm 2 , 0.29 cm 2 , 0.22 cm 2 and 0.17 cm 2 It was.

[0207] In conclusion, the ZnO / Co3O4@Gr / GCE working electrode showed enhanced electrocatalytic activity with larger EASA, reduced resistance, and peak separation.

[0208]

[0209] Experimental Example 6: Measurement of the Electrical Performance of Alfuzosin (AFZ) as an Electrochemical Biosensor 1

[0210] By utilizing the excellent electrical conductivity of the ZnO / Co3O4@Gr / GCE (working electrode) manufactured in Manufacturing Example 1, an evaluation was performed on whether this electrode could be used for AFZ detection, and the results are shown in Fig. 5.

[0211] (1) Figure 5 (a) shows the results of cyclic voltammetry (CV) measurements of a bare GCE and a modified electrode, Gr / GEC and ZnO / Co3O4@Gr / GCE of Preparation Example 1, in 0.1 M PBS (pH 7.0) containing 1 mM AFZ at a scan rate of 100 mV / s.

[0212] Pure GCE has the lowest oxidation peak current response (I pa =14.51μA), which means that electron transport was hindered. And, Gr / GCE(I pa =26.89μA) and ZnO / Co3O4@Gr / GCE(I pa =55.29μA) showed a noticeably higher current response, confirming that graphene improves the electronic conductivity of ZnO / Co3O4.

[0213] (2) And, looking at Fig. 5 (b), ZnO / Co3O4@Gr / GCE showed the maximum oxidation peak current response compared to pure GCE, which was caused by the synergistic interaction of the nanocomposite that increases the oxidation peak current of AFZ and the large electrochemically active surface area.

[0214] (3) The results were performed at a consistent scan rate of 100 mV / s using various AFZ concentrations (0–200 μM) in 0.1 M PBS (pH 7.0), and the results are shown in (c) of Fig. 5. As can be seen in (c), the peak current value increased linearly when AFZ was added, and the linear regression equation I pa (μA)=0.285 C AFZ [μM]+16.595, R 2The calibration curve using a coefficient of 0.9971 exhibited excellent linearity. These results demonstrate the strong antifouling activity of ZnO / Co3O4@Gr / GCE for AFZ detection. The solution pH may have influenced the analyte behavior and the electron transfer rate toward the nanocomposite electrode.

[0215] (4) The effect of pH on the electrochemical response for 1 mM AFZ containing ZnO / Co3O4@Gr / GCE was investigated using CV reactions at various pH levels (range pH 5.0 to pH 9.0) at a scan rate of 100 mV / s, and is shown in Fig. 5(d).

[0216] As the pH of the electrolyte increased from 5.0 to 7.0, the peak current intensity increased and then decreased from pH 7.0 to pH 9.0. Furthermore, the peak potential of the CV curve showed a slight shift toward negative potential, which can be explained by changes in the acid-base protonation function of the AFZ molecule. The electrooxidation of AFZ was successful at pH 7.0 due to good resolution and the formation of sharp, strong peaks.

[0217] (5) The plot of peak current and various pH values ​​in Fig. 5(e) showed that the maximum AFZ oxidation peak current was observed at pH 7.0, which was used throughout the experiment.

[0218] E pa The plot of pH vs. linear equation E pa =-0.051C AFZ (pH)+0.9883, R 2 = 0.9965 using the oxidation peak potential (E pa ) shows a linear correlation with various pH values. The slope value is close to the Nernstian theoretical value of -0.059 V for pH, which means that the electrooxidation of AFZ involves an equal number of electrons and protons. This finding is consistent with the mechanism of the AFZ electrooxidation reaction described in Equation 2.

[0219] [Equation 2]

[0220] Ep=E°+(2.303RT / (1-αnF))logv+(2.303RT / 1-αnF))log(nF(1-α)RTKs)

[0221] Here, E° is the formal potential, α is the electron transfer coefficient, and k s Is where n is the standard electron transfer rate constant, v is the scan rate, and n is the number of electrons involved in the reaction. The remaining R, T, and F values ​​are constant.

[0222] (6) The response of 1 mM AFZ to ZnO / Co3O4@Gr / GCE was also investigated using CV at various scan rates, and the results are shown in Fig. 5 (f).

[0223] As the scan rate increased from 10 to 200 mV / s, the oxidation peak current of AFZ increased and the anodic potential gradually shifted to higher values. In addition, the related linear regression equation I pa (μA)=0.450 C AFZ v(mV / s)+4.654, R 2 = 0.9948 using I pa A linear plot of various scan rates for is shown in Fig. 5(g). These results indicate an adsorption-controlled AFZ system on the ZnO / Co3O4@Gr / GCE surface.

[0224] Also, log I p was also linear with respect to log v (Fig. 5(h)), and the corresponding linear equation was log I pa (μA)=0.985C AFZ log v(mV / s)0.016, R 2 =0.9974.

[0225] A slope of 1.00 is expected for an ideal surface reaction, and the observed slope of 0.98 confirms that the AFZ electrooxidation reaction is adsorption-controlled kinetics. The electrochemical kinetic parameters for the irreversible electrochemical process were calculated according to the Laviron equation 2 above and equation 3 below.

[0226] [Equation 3]

[0227] Log K s = αlog(1-α)+(1-α)logα-log(RT / nFv)-α(1-α)nFΔE p / 2.3RT

[0228] Here, E° is the formal potential, α is the electron transfer coefficient, and k s Is where n is the standard electron transfer rate constant, v is the scan rate, and n is the number of electrons involved in the reaction. The remaining R, T, and F values ​​are constant.

[0229] And, peak potential (E pa ) showed excellent linearity with respect to the logarithm of the scan rate ((i) in Fig. 5), and the corresponding linear regression equation was E pa (V)=0.061C AFZ (log v)+0.706, R 2 =0.9967. Next, log v vs. E pa Using the slope values ​​of 'α' (0.54) and 'n' (1.96, corresponding to 2) were calculated. Using equation (2), 'k s ' is 0.73 s -1 It was estimated to be.

[0230]

[0231] Experimental Example 7: Electrical Performance Measurement 2 as an Electrochemical Biosensor for Alfuzosin (AFZ)

[0232] (1) The response of the fabricated sensor to AFZ electrooxidation was evaluated using a sensitive, accurate, and reliable DPV (differential pulse voltammetry) approach, and the results are shown in Fig. 6. The ZnO / Co3O4@Gr / GCE fabricated in Manufacturing Example 1 was applied as the working electrode of the biosensor.

[0233] Experimental parameters affecting the DPV response, including pulse amplitude, pulse period, potential increment, pulse width, and sampling width, were optimized for AFZ in 0.1 M PBS (pH 7.0). Ideal values ​​for each parameter were selected to achieve the highest peak current and best signal resolution.

[0234] The optimal values ​​for these variables are:

[0235] Pulse amplitude = 0.05 V, pulse period = 0.5 s, potential increment = 0.004 V, pulse width = 0.05 s, sampling width = 0.016 s.

[0236] Figure 6(a) shows the DPV analysis of AFZ on ZnO / Co3O4@Gr / GCE. The synergistic activity and non-covalent contact between ZnO / Co3O4 and graphene (Gr), which enhance the electrochemical performance of AFZ electrooxidation, are shown in Fig. 6(a) and (b). The peak current (I pa ) resulted in a gradual increase in the intensity of the I pa The calibration plot for the AFZ concentration (range 0.05–40 μM) is shown in Fig. 6(b) and shows two linear regions. At lower concentrations, the AFZ molecules migrate quickly to the electrode surface, resulting in a very fast reaction, whereas at higher concentrations, the reaction is slower.

[0237] Therefore, two linear regions were obtained due to this irregular response. The linear range at lower concentrations was obtained between 0.05 and 4.0 μM, and the corresponding regression equation was I pa (μA)=0.195C AFZ[μM]+7.372, (R 2 = 0.9966).

[0238] A higher concentration linear range was achieved between 5.0 and 40 μM and the appropriate regression equation was I pa (μA)=0.083C AFZ [μM]+12.272, (R 2 = 0.9917).

[0239] And, the limit of detection (LOD) value was found to be 0.004 μM using the relationship 3S / m, where 'S' represents the standard deviation and 'm' represents the slope.

[0240] A comparison of the fabricated sensor with a previously reported AFZ sensor is shown in Fig. 7 below.

[0241] (2) In the presence of uric acid (UA), the ability of the newly configured sensor to selectively detect AFZ, i.e., the detection selectivity and detection sensitivity for AFZ, are important.

[0242] The DPV curves of the sensor for selectively detecting AFZ and UA in 0.1 M PBS (pH 7.0) are shown in Fig. 6 (c) and (d).

[0243] The peak currents of AFZ (Fig. 6(c)) and UA (Fig. 6(d)) steadily increased with increasing concentrations of AFZ (5–30 μM) and UA (5–80 μM), respectively, whereas the peak currents of other molecules did not change at fixed concentrations. Linear regression equations I inserted in Fig. 6(c) and (d) pa (μA)=0.290C AFZ [μM]+8.186,(R 2 =0.9950) and I pa (μA)=0.218C UA [μM]+9.943, (R 2 =0.9962) was used to present the calibration curves for AFZ and UA.

[0244] Figure 6e shows a well-resolved DPV curve with a gradual increase in peak current intensity with the synchronous addition of AFZ and UA. Furthermore, the linear regression equation I pa (μA)=0.157C AFZ [μM]+16.432, (R 2 =0.9963) and I pa (μA)=0.170C UA [μM]+13.148, (R 2 The calibration plots of AFZ and UA with (=0.9906) are shown in (f) of Fig. 6.

[0245] Through the above DPV (differential pulse voltammetry) evaluation, it was confirmed that the biosensor using ZnO / Co3O4@Gr / GCE as a working electrode had excellent detection selectivity for AFZ and excellent detection sensitivity (low detection limit).

[0246]

[0247] Experimental Example 8: Evaluation of Detection Stability and Reproducibility as an Electrochemical Biosensor for Alfuzosin (AFZ) Detection

[0248] In practical biosensing applications, it is important to evaluate the interference of excipients such as some commonly used biological metabolites and inorganic compounds in addition to uric acid (UA) on AFZ detection.

[0249] Here, the selectivity of the biosensor was evaluated by adding biologically active compounds such as dopamine (DA), tyrosine (TY), and folic acid (FA) in excess of 10-fold to 0.1 M PBS (pH 7.0) containing 1 mM AFZ using DPV technology, and the results are shown in Fig. 8.

[0250] (1) Looking at Fig. 8 (a), it was shown that the biosensor did not exhibit a significant peak potential change, which means that the biologically active chemical did not interfere with the detection of AFZ.

[0251] Additionally, the effect of selected interfering species interfering with 1 mM AFZ in the presence of 0.1 M PBS (pH 7.0) was investigated as shown in Fig. 8(b). These species included cations (Fe 2+ , Co 2+ , Na + , K + and Ca 2+ ), anion (SO4 2- , NO3 - , and Cl - ), ascorbic acid (AA) and glucose (Glu) were included at concentrations exceeding 10 times.

[0252] The oxidation peak current did not change significantly with the addition of the interference species, as shown in Fig. 8(b), and the histogram of the oxidation current response to various interference species showed a relative error of less than 5% (Fig. 8(c)). This demonstrates the strong selectivity of the ZnO / Co3O4@Gr / GCE viasensor for AFZ detection.

[0253] (2) In addition, the long-term electrochemical stability of the sensor was investigated in 0.1 M PBS (pH 7.0) containing 1 mM AFZ at a scan rate of 100 mV / s for 20 days using the CV approach, and the results are shown in Fig. 8 (d). This experiment was performed every 5 days after storing the working electrode in a refrigerator at 4°C.

[0254] As can be seen in the bar graph of Fig. 8 (e), the sustained peak current was 95.6% of the initial peak current, demonstrating the excellent durability, i.e., stability, of the ZnO / Co3O4@Gr / GCE sensor.

[0255] (3) In addition, five biosensors using ZnO / Co3O4@Gr / GCE were manufactured, and the reproducibility was evaluated using the CV approach, which is shown in (f) of Fig. 8. The evaluation results showed a relative standard deviation (RSD) of 3.2% (insert of (f) of Fig. 8), which confirmed that ZnO / Co3O4@Gr / GCE had excellent reproducibility.

[0256]

[0257] Experimental Example 9: Practical Application Evaluation of Alfuzosin (AFZ) Detection as an Electrochemical Biosensor

[0258] Considering the sensitivity and selectivity of the biosensor fabricated with ZnO / Co3O4@Gr / GCE as the working electrode, the possibility of detecting AFZ in real samples was evaluated.

[0259] The real-time applicability of the biosensor using ZnO / Co3O4@Gr / GCE of Preparation Example 1 was tested using the DPV approach in AFZ-containing pharmaceutical tablets and AFZ-free human serum and urine samples using the standard addition method, and the results are shown in Fig. 9. The recovery rates are also shown in Table 2 below.

[0260] (a) DPV curve data for AFZ-containing pharmaceutical tablet sample, (c) urine sample, and (e) human serum without AFZ, and (b), (d), and (f) respectively show the linear relationship between the peak current and the AFZ concentration in the actual sample.

[0261] Through the results in FIG. 9 and Table 2, it was confirmed that the biosensor using ZnO / Co3O4@Gr / GCE of the present invention has an acceptable recovery rate capable of monitoring AFZ in an actual sample.

[0262] Sample AFZ Addition Amount (μM) AFZ Detection Amount (μM) Recovery Rate (%) ALFOO Purified Sample 54.9699.20 109.8998.90 1514.9699.73 Urine Sample 54.9398.60 109.9499.40 1514.9399.53 Human Serum 54.9899.60 109.8898.80 1514.5897.20

[0263] Through the above examples and experimental examples, it was confirmed that the GCE modified with ZnO / Co3O4@Gr (ZnO / Co3O4@Gr / GCE) has excellent electroanalytical properties, which makes it suitable for application as a working electrode of a biosensor for detecting AFZ, an α1-AR antagonist. In addition, the DPV results showed an excellent linear range of 0.05 to 40 μM with a low LOD of 0.004 μM for AFZ detection. In addition, due to the synergistic effect of ZnO / Co3O4 and Gr, the biosensor had high selectivity for AFZ, excellent interference prevention function, durability, and reproducibility.

[0264] Furthermore, the sensor's potential for real-time detection of AFZ in biological (urine and serum) and pharmaceutical (tablet) samples was confirmed with significant recovery rates.

[0265] This suggests that the ZnO / Co3O4@Gr / GCE of the present invention has great potential for various applications in electrochemical sensing-related fields as a low-cost, environmentally friendly biosensor material.

[0266]

[0267] Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

Claims

1. It is an electrochemical biosensor electrode material for detecting alfuzosin. ZnO and Co on graphene 3 O 4 ZnO / Co combined 3 O 4 A metal-organic framework for an electrochemical biosensor electrode characterized by being a binary metal-organic framework with a nanocomposite fixed thereon.

2. In the first paragraph, with respect to 100 parts by weight of the graphene, ZnO / Co 3 O 4 A metal-organic framework for an electrochemical biosensor electrode, characterized in that it contains 50 to 150 parts by weight of a nanocomposite.

3. In the first paragraph, the ZnO / Co 3 O 4 Nanocomposites are, A metal-organic framework for an electrochemical biosensor electrode, characterized in that it contains 8.00 to 11.50 atom% of cobalt (Co), 29.00 to 32.00 atom% of zinc (Zn), and 100 atom% of oxygen (O).

4. In the first paragraph, the two-component metal-organic framework is, A metal-organic framework for an electrochemical biosensor electrode, characterized in that it contains 3.20 to 5.00 atom% of cobalt (Co), 6.00 to 8.00 atom% of zinc (Zn), 23.0 to 25.20 atom% of oxygen (O), and the remainder of 100 atom% of carbon (C).

5. Step 1: Preparing ZIF-Zn; Step 2: adding the ZIF-Zn to a cobalt supply solution containing cobalt nitrate hexahydrate dissolved in methanol, adding 2-MIM (methylimidazole) solution dropwise and stirring the resulting mixture, co-precipitating it, and then filtering it to obtain a solid; Step 3: Washing the above solid and drying it at 75 to 90°C to obtain bimetallic ZIF (Zeolitic imidazole framework)-ZnCo; By sintering the above bimetallic ZIF-ZnCo, ZnO and Co 3 O 4 ZnO / Co combined 3 O 4 4 steps to fabricate nanocomposites; Step 5: Adding 5 to 15 mg of graphene per 10 ml of ethanol, sonicating to prepare a graphene dispersion, and then centrifuging to collect the graphene; After preparing a diluted solution by diluting 5 to 15 mg of the collected graphene per 10 ml of ethanol, the ZnO / Co was added to the diluted solution. 3 O 4 After adding 5 to 15 mg of nanocomposite, ultrasonic treatment was performed, and centrifugation was performed to obtain ZnO / Co 3 O 4 Nanocomposite-anchored graphene composite (ZnO / Co 3 O 4 Step 6 to obtain @Gr); and Obtained ZnO / Co 3 O 4 A method for manufacturing a metal-organic framework for an electrochemical biosensor electrode, characterized by performing a process including the step of washing and drying a graphene composite having a nanocomposite fixed thereon.

6. In the fifth paragraph, the cobalt supply solution of step 2 contains 1.20 to 2.00 mmol of cobalt nitrate hexahydrate per 40 ml of methanol, The above 2-MIM solution contains 13.00 to 18.00 mmol of 2-MIM per 40 ml of methanol, A metal-organic framework for an electrochemical biosensor electrode, characterized in that the ZIF-Zn addition amount is 0.15 to 0.40 g of the ZIF-Zn per 40 ml of a cobalt supply solution.

7. In the fifth paragraph, the bimetallic ZIF-ZnCo of the third step contains 28.00 to 32.00 atom% of nitrogen (N), 0.40 to 0.75 atom% of cobalt (Co), 1.00 to 1.35 atom% of zinc (Zn), and the remainder of carbon (C) among 100 atom%, The above ZnO / Co in step 4 3 O 4 A metal-organic framework for an electrochemical biosensor electrode, wherein the nanocomposite comprises 8.00 to 11.50 atom% of cobalt (Co), 29.00 to 32.00 atom% of zinc (Zn), and 100 atom% of oxygen (O).

8. In paragraph 5, The above ZnO / Co per 10 ml of the above diluted solution in step 5 3 O 4 A method for producing a metal-organic framework for an electrochemical biosensor electrode, characterized by introducing 5 to 15 mg of a nanocomposite.

9. A method for producing a metal-organic framework for an electrochemical biosensor electrode, characterized in that in the fifth paragraph, the calcination in step 4 is performed at 380 to 450°C for 1.5 to 3.0 hours.

10. A working electrode for an electrochemical biosensor, characterized by comprising a metal-organic framework selected from any one of claims 1 to 4.

11. A working electrode for an electrochemical biosensor, characterized in that it comprises a glassy carbon electrode modified with the metal-organic framework according to claim 10.

12. Step 1 of preparing a dispersion mixture of methanol and a metal-organic framework selected from any one of claims 1 to 3; and A method for manufacturing a working electrode for an electrochemical biosensor, characterized by performing a process including the second step of coating the surface of a glass carbon electrode with the above dispersion and then drying it by irradiating it with infrared rays.

13. A method for manufacturing a working electrode for an electrochemical biosensor, characterized in that in the 12th paragraph, the dispersion of step 1 is manufactured by adding 0.5 to 1.5 mg of the metal-organic framework per 1 ml of methanol and then homogenizing it through ultrasonic treatment.

14. An electrochemical biosensor equipped with the working electrodes of clause 10, An electrochemical biosensor characterized by being a non-enzymatic electrochemical sensor used for quantitative and qualitative detection of alfuzosin.

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