KR20170085320A - Reduced Graphene Oxide Modified Interdigitated Chain Electrode, method for preparing thereof, the rGO-ICE based Insulin Sensor, and method for preparing thereof - Google Patents

Reduced Graphene Oxide Modified Interdigitated Chain Electrode, method for preparing thereof, the rGO-ICE based Insulin Sensor, and method for preparing thereof Download PDF

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KR20170085320A
KR20170085320A KR1020160004790A KR20160004790A KR20170085320A KR 20170085320 A KR20170085320 A KR 20170085320A KR 1020160004790 A KR1020160004790 A KR 1020160004790A KR 20160004790 A KR20160004790 A KR 20160004790A KR 20170085320 A KR20170085320 A KR 20170085320A
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조성보
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Abstract

The present invention relates to an rGO-ICE electrode, a reduced graphene oxide (rGO) deposited on an ICE (Interdigitated Chain Electrode) electrode, a method for producing the electrode, and a method for manufacturing the rGO- To an insulin sensor and a method of manufacturing the same.
According to the present invention, a rGO-modified ICE electrode (rGO-ICE) capable of reducing the influence of the edge concentration of an electric field on a typical square-shaped IDE electrode was produced by forming the detection electrode shape in a round shape in the ICE . The rGO-deposited ICE electrode according to the present invention can be used as a biosensor capable of measuring insulin concentration. Further, the insulin sensor according to the present invention can be used for biomarkers that do not require labels, can be measured in real time, and for diagnosis at a medical field.

Description

TECHNICAL FIELD [0001] The present invention relates to an ICE electrode on which reduced graphene oxide is deposited, a method for producing the same, an insulin sensor based on the ICE electrode on which the reduced graphene oxide is deposited, and a method for preparing the same , the rGO-ICE based insulin sensor, and a method for preparing the same]

The present invention relates to an ICE electrode deposited with reduced graphene oxide, a method for producing the ICE electrode, an insulin sensor based on the ICE electrode deposited with the reduced graphene oxide, and a method for producing the ICE electrode.

The human insulin protein (Human insulin protein, 5.8 kDa) consists of two peptide chains, the A chain and the B chain, which are coupled to each other by a disulfide bond with 51 amino acids. Insulin deficiency can cause diabetes mellitus or hyperglycemia associated with high blood sugar levels in the human body. The World Health Organization estimates that 9% of adults have diabetes and that more than 90% of adult diabetics have type 2 diabetes. There is an increasing need to detect insulin levels for the diagnosis or treatment monitoring of diabetes or insulinoma. Insulin levels have usually been measured by radioassay, enzyme-linked immunosorbent assay, turbidimetry, and chromatography. Recent advances in sensors have been proposed for measuring biomarkers that are more accurate, faster, easier, and more cost-effective, which is either selective or complementary to recognized methods.

For direct and effective measurement of biomarkers, electrochemical impedance spectroscopy (EIS) using biosensors based on microelectrodes has been recommended since label-free, real-time measurement assays have been provided. EIS has been used to characterize the electrical properties of the electrode interface by detecting changes in the electric field distributed at the electrodes generated by the adsorption or immobilization of the molecules. Many of the nano- or micro-interdigitated electrodes have been applied since the electric field can be limited by the gap of the electrode close to the electrode surface. Due to the small separation distance between the IDE electrodes, the collection efficiency of analytical ions with reduced equilibration time is increased. In addition, the signal for the noise ratio can be measured by electrode thickness, which is one of the structural factors that can be considered to increase the measurement sensitivity. Because the electric field has a tendency to be more concentrated at the electrode edges, impedance measurements are mostly achieved by the analyte located at the edge of the electrode, resulting in an imbalance in the detection region.

Thus, methods for modifying the electrode surface using deposition of nanoparticles, nanowires, or grapins have been studied to achieve better measurement sensitivity and increase the binding efficiency of the target analyte.

On the other hand, graphene is a 2D nanomaterial having excellent electron and mechanical properties, and is an ideal candidate for an electrode material. Many efforts have been made to fabricate graphene coated electrodes to increase the efficiency of electrode-based biosensors. Reduced graphene oxide (rGO) can be prepared by depositing on various electrodes such as glassy carbon, indium tin oxide (ITO), or gold, and polymers with high sensitivity in a wide range of electrochemical detection systems have.

The electrocatalytic activity of rGO is derived from its edge defects which act as mediators and the edge surface of the analyte and the electrode rGO has a larger noncircuitable capacity, Electron transport rate, and strong electrocatalytic activity). In addition, rGO was deposited on electrodes as a mixed material with various nanoparticles such as gold (Au), platinum (Pt) or silver (Ag).

 Zhao, Z. Y .; Zhang, M. M.; Chen, X .; Li, Y.J .; Wang, J. Electrochemical co-reduction synthesis of aupt bimetallic nanoparticles-graphene nanocomposites for selective detection of dopamine in the presence of ascorbic acid and uric acid. Sensors-Basel 2015, 15, 16614-16631.

Conventionally, the structure of the electrodes used in the biosensor has a rectangular shape. Due to such an electrode structure, the electric field tends to be more concentrated at the electrode edge. Therefore, an electrode having a novel structure capable of solving the problem of imbalance in the detection region due to the impulse current in the region excluding the edge portion of the electrode has been studied.

Therefore, it is an object of the present invention to provide a rGO-modified ICE electrode that has a novel electrode structure to have a uniform sensitivity throughout the electrode structure by reducing the effect of edge concentration of the electric field, and which can measure capacitance or non- .

Another object of the present invention is to provide a method of manufacturing the rGO-modified ICE electrode.

It is another object of the present invention to provide an insulin sensor and a method of manufacturing the same based on the rGO-modified ICE electrode.

In order to achieve the above object, the electrode of the present invention is an rGO-ICE electrode deposited with reduced graphene oxide (rGO) on an ICE (Interdigitated Chain Electrode) electrode.

Preferably, the deposited reduced graphene oxide has a rounded shape with corners of the corrugated sheets and interconnected wrinkled sheets.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: patterning an ICE electrode on a substrate; insulating the electrode chip of the ICE electrode; and depositing reduced graphene oxide on the detection region of the ICE electrode (RGO-ICE) with a reduced graphene oxide deposited thereon.

The ICE electrode may be indium tin oxide (ITO).

The ICE electrode chip may be insulated using polydimethylsiloxane (PDMS).

Deposition of the reduced graphene oxide may be by using chronoamperometry.

In addition, the present invention provides an rGO-ICE based insulin sensor based on the rGO-ICE electrode.

The insulin sensor may include an insulator layer formed on the rGO-ICE electrode layer, an antibody immobilized on the insulator layer, and an insulin antigen bound to the antibody.

According to an embodiment of the present invention, the insulating layer may be made of aminopropyl triethoxysilane (APTES), and the insulating layer may be a self-assembled monolayer (SAM).

According to one embodiment of the present invention, glutaraldehyde (GA) may be used as an agent for immobilizing the antibody.

According to an embodiment of the present invention, BSA (Bovine Serum Albumin) may be used as a blocking agent for preventing nonspecific adsorption to the surface of the rGO-ICE electrode layer, and immobilized in the void space between the antibody and insulin molecules .

The present invention also relates to a method for preparing a rGO-ICE electrode, comprising the steps of forming an insulating layer on an rGO-ICE electrode layer, immobilizing an antibody on the insulating layer, and immobilizing a BSA (Bovine Serum Albumin) blocker to prevent nonspecific adsorption onto the surface of the rGO- And a step of binding the insulin antibody to the insulin antibody and immobilizing the insulin antibody to the insulin antibody, thereby providing a method of manufacturing an rGO-ICE based insulin sensor.

According to the present invention, an rGO-modified ICE electrode (hereinafter referred to as " rGO-ICE ") capable of reducing the influence of the edge concentration of an electric field in a typical square-shaped IDE electrode by forming a detection electrode shape in a round- ).

The rGO-deposited ICE according to the present invention provides excellent analyte-binding effect and measurement sensitivity. Using the prepared rGO-ICE, direct capacity or non-faradaic measurement on the electrode surface due to electrode modification, adsorption of biomolecules, and antigen-antibody binding were investigated. The ferro- Or an indirect measurement of charge transfer ions such as a redox couple of ferrocyanide (ferrocyanide).

The rGO-deposited ICE electrode according to the present invention can be used as a biosensor capable of measuring insulin concentration. Further, the insulin sensor according to the present invention can be used for biomarkers that do not require labels, can be measured in real time, and for diagnosis at a medical field.

1 is an optical image (a) of an ICE produced on a glass substrate with a PDMS chamber attached, and is a phase contrast micrograph (b, c) of the bare ICE and rGO deposited ICE detection electrodes, (D) is a photograph (e) showing enlarged surface structure of one of the electrode arms of (d).
FIG. 2 is a schematic diagram illustrating a manufacturing process of an rGO-ICE-based insulin sensor.
Fig. 3 shows the impedance magnitudes of rGO-ICE measured according to (a) bare ICE, (b) rGO-ICE, (c) bare ICE phase, and (d) PBS concentration; Each graph is fitted using an equivalent circuit model consisting of the solution resistance (Rs), the phase component constant at the electrode interface impedance (CPE), and the insulation capacitance of the solution (C DE ).
FIG. 4 shows (a) the reactivity capacity of the impedance data measured in a 1 × PBS solution (pH 7.0) according to the manufacturing process of the rGO-ICE-based insulin sensor, and (b) the resistance value.
Figure 5 shows (a) the normalized dose measured according to the insulin concentration diluted in PBS

Figure pat00001
), (b) an insulin concentration range of 1 ng / ml to 10 g / ml
Figure pat00002
at 4.7 kHz .
Figure 6 (a) the insulin concentration is diluted in human serum (HS C - insuline) Normalized dose of the (
Figure pat00003
); (b) an insulin concentration range of 1 ng / ml to 10 < RTI ID = 0.0 >
Figure pat00004
at 4.7 kHz .

Hereinafter, the present invention will be described in more detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

The present invention relates to an electrode having a high sensitivity throughout the electrode by changing the shape of an electrode structure used in the biosensor, a method of manufacturing the electrode, and a biosensor based on the electrode and a method of manufacturing the same.

Insulin is a key regulator for glucose homeostasis, and when insufficient or replaced in the human body, it causes various forms of diabetes mellitus.

In the case of conventional rectangular electrodes, the electric field tends to concentrate only toward the corners, and the electrode body is not crowded with current, resulting in imbalance, which results in a decrease in measurement sensitivity.

In the present invention, an ICE electrode modified with reduced graphene oxide (rGO) capable of directly detecting the capacity of insulin has been developed. That is, the electrode according to the present invention is characterized by an ICD (Interdigitated Chain Electrode) electrode (hereinafter referred to as "rGO-ICE") deposited with reduced graphene oxide (rGO).

The electrode according to the present invention has a structure in which a reduced graphene oxide is deposited on an ICE electrode, and the deposited reduced graphene oxide has a rounded shape with corners and wrinkled sheets connected to each other. Therefore, in ICE, the sensing electrodes have rounded shapes with no angular corners, so that they have a chain-like shape, which reduces the effect of the edge concentration of the electric field on a typical square-shaped IDE electrode.

The method of manufacturing the rGO-ICE electrode according to the present invention includes the steps of patterning an ICE electrode on a substrate, insulating an electrode chip of the ICE electrode, and depositing a reduced graphene oxide on a detection region of the ICE electrode . ≪ / RTI >

The ICE electrode is preferably made of indium tin oxide (ITO), and the ITO electrode is composed of a detection region, a transmission line, and a terminal pad.

In order to insulate the transmission line, it is preferable to pattern on the electrode substrate using a low-conductivity photoresist.

Also, in the present invention, it is preferable to insulate the ICE electrode chip by using polydimethylsiloxane (PDMS) in order to maintain the liquid phase during the electrical deposition of the graphene oxide, the incubation and the impedance measurement. (See Fig. 1)

Also, in the present invention, it is preferable to use a chronoamperometry method for depositing the reduced graphene oxide on the ICE electrode. The time-current method is preferably performed at room temperature (r.t.).

Also, the present invention provides an rGO-ICE based insulin sensor based on the rGO-ICE electrode.

The rGO-ICE based insulin sensor according to the present invention is a structure including an insulator layer formed on the rGO-ICE electrode layer, an antibody immobilized on the insulator layer, and an insulin antigen bound to the insulin antibody.

The insulating layer may be made of aminopropyl triethoxysilane (APTES), and the insulating layer may be a self-assembled monolayer (SAM).

Further, in the present invention, it is preferable to use glutaraldehyde (GA) as a medium for immobilizing the antibody.

In addition, before binding of the insulin antigen to the antibody, BSA (Bovine Serum Albumin) is used as a blocking agent to prevent nonspecific adsorption to the surface of the rGO-ICE electrode layer, and an empty space between the antibody and the insulin molecules (Ab-Ins) It is preferable to fill the space.

The method for preparing an rGO-ICE based insulin sensor according to the present invention comprises the steps of forming an insulating layer on an rGO-ICE electrode, immobilizing an antibody on the insulating layer, preventing nonspecific adsorption on the surface of the rGO- Forming a BSA (Bovine Serum Albumin) blocker, and binding and inserting the insulin antigen to the insulin antibody.

Referring to FIG. 2, the rGO-ICE electrode according to the present invention and the whole process of immobilizing biomolecules on the electrode are shown. First, reduced graphene oxide is deposited on the ICE electrode to form rGO -ECICE electrode is manufactured.

Next, the rGO-ICE electrode is immersed in an aqueous solution of 3-aminopropyl triethoxysilane (APTES) for a predetermined time to react with the? H group of the graphene oxide for immobilization of the antibody. At this time, the 3-aminopropyltriethoxysilane forms a self-assembled monolayer (SAM) insulating layer.

A glutaraldehyde (GA) solution was also allowed to react with the APTES modified electrode and activated for antibody immobilization. The glutaraldehyde (GA) solution can be reacted by drop-casting onto the APTES modified electrode.

Then, an insulin antibody solution (Ab-Ins) was dropped-cast on the detection electrode surface to immobilize it on the rGO electrode-APTES. The antibody according to the present invention includes immunoglobulin G (IgG), but it is not limited thereto, and various antibodies known in the art can be used.

In the present invention, BSA was immobilized with a blocking agent in order to prevent nonspecific adsorption to the electrode surface. Therefore, it is preferable that the BSA is filled in the void space between the antibody and the insulin molecules (Ab-Ins).

Finally, the method may include immobilizing an insulin antigen to the antibody.

The rGO-ICE-based insulin sensor according to the present invention can confirm that insulin is effectively detected through impedance measurement and capacity change.

In addition, the detection of the rGO-ICE-based insulin sensor according to the present invention can be confirmed using various concentrations of insulin prepared in human serum.

In addition, the rGO-ICE-based insulin sensor according to the present invention has biocompatibility with various biomolecules since it maintains bioactivity without any denaturation throughout the storage period.

Therefore, the proposed sensor of the present invention can be used for biomarkers that do not require a label, can be measured in real time, and for diagnosis at a medical field.

Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are intended to illustrate the present invention, but the scope of the present invention should not be construed as being limited by these examples. In the following examples, specific compounds are exemplified. However, it is apparent to those skilled in the art that equivalents of these compounds can be used in similar amounts.

Example  One

One) rGO - ICE Manufacturing

An indium tin oxide (ITO) electrode was patterned on a slide glass substrate (75 x 25 x 1 mm, Tae Young Optics Co., Ltd., Incheon, South Korea). The patterned ITO electrode is composed of a detection region, a transmission line and an end terminal. A low-conductivity photoresist (SU-8 2002, Microchem, Newton, MA, USA) was patterned on the electrode substrate to insulate the transmission line. The diameter and spacing of interdigitated fingers were 40 ㎛ and 20 ㎛, respectively. A polydimethylsiloxane (PDMS) chamber was then attached to the electrode chip to maintain the liquid phase during electrical deposition and incubation and impedance measurements of graphene oxide (see FIG. 1A)

A solution of the graphene oxide on the phosphate buffer (0.5 mM) was poured into the chamber and a voltage of -1.4 V against Ag / AgCl was applied for 20 seconds at room temperature (rt) to the sensing electrode of the ICE using chronoamperometry . The rGO-deposited ICE (rGO-ICE) was washed with purified water and dried under a nitrogen atmosphere. Micrographs were taken before and after rGO deposition and the results are shown in Figures 1 (b, c).

In addition, the deposition of the rGO layer on the electrode was clearly confirmed from scanning electron micrographs of electrode arms and surface structure of rGO electrodeposited on ICE. The deposited rGO was shaped like a wrinkled sheet (see Fig. 1 (d, e)).

Example  2 : rGO - ICE based  Insulin sensor manufacturing

ICE detection electrode was immersed in 100 μl of 5% (v / v) 3-aminopropyltriethoxysilane (APTES, 99%) in purified water for immobilization of the insulin antibody on the surface of the sensor rt) for 3 hours. The electrode for a next, 1% (v / v) glutaraldehyde rGO the ICE-detecting electrode to 50㎕ (GA, 50% in H 2 O, 1xPBS, pH 7.4) , washed with purified water (18.2 MΩ · cm) Drop-cast and allowed to react with the APTES modified electrode for 1 hour. Then, 10 μl of an insulin antibody (IgG) solution (Ab-Ins; 10 μg / ml) was cast on the detection electrode surface and bound to have an APTES / rGO electrode surface. BSA (1 ng / ml) in PBS (10 mM, pH 7.4) was used to prevent nonspecific adsorption to the electrode surface.

In this example, PBS (1 x PBS, 137 mM NaCl, 2.7 mM KCl, 4.3 mM Na 2 HPO 4 and 1.4 mM KH 2 PO 4 , pH 7.4), and a 10 mu l aliquot of the sample was added to the prepared insulin sensor and incubated at 4 DEG C for 60 minutes.

All the steps involved in electrode preparation and immobilization of biomolecules to rGO-ICE are illustrated in FIG. 2 below.

Experimental Example  One : rGO  Deposited ICE Impedance characteristics of

Electrochemical deposition of rGO on ICE or EIS measurements on developed sensors was performed using apotentiostat (CompactStat, IVIUM, Eindhoven, Netherlands). The measured impedance spectra were nonlinear curve fit analysis using a predetermined equivalent circuit model via commercially available Z view software (Scribner Associates Inc., Southern Pines, NC, USA).

The impedance spectrum of the pure or rGO deposited ICE measured in PBS without any redox probe is shown in FIG.

Impedance magnitude and phase were recorded in the frequency range between 10 Hz and 1 MHz for the concentration of PBS ( C PBS ).

The impedance characteristics of the electrodes are determined by: i) the insulation capacitance (C DE ) of the solution at high frequencies, ii) the solution resistance (R S ) at the intermediate frequency, and iii) the phase composition Constant phase element (CPE)

The CPE admittance of the (admittance) = T · jω) P, where T and P is a variable variable (adjustable parameters), j is an imaginary unit (imaginary unit) is, ω is the angular frequency (angular frequency), ω = 2πf And f is the frequency.

Table 1 summarizes the extrapolated values of the circuit components from the correction results of FIG.

Figure pat00005

Referring to Table 1, it can be seen that, in the case of the rGO-ICE electrode, as the concentration of PBS increases, C DE increases while R S decreases. It can be seen that the deposition of rGO is reduced for 1 / T and P, indicating increased surface roughness throughout the electrode area.

On the other hand, in the bare-ICE electrode, P is close to 1, which means that most of the electrode interface impedance contributed to the capacitive reactance.

In addition, fitting analysis was performed on the spectrum measured using PBS, and it was confirmed from the results shown in FIG. 3 that the impedance characteristic of the manufactured rGO-ICE can be well explained by a predetermined equivalent circuit model .

Experimental Example  2: In insulin detection BSA / Ab - Ins / GA / APTES / rGO - ICE of EIS  analysis

Reactive capacity (C) and resistance (R) according to the manufacturing process of the rGO-ICE-based insulin sensor were measured according to the frequency domain, and the results are shown in FIG.

Referring to this, according to the manufacturing process of the rGO-ICE-based insulin sensor, the reactive capacity (C) was gradually decreased in the frequency range of 100 Hz to 100 kHz, and at the same time, the resistance at 1 kHz or less was increased , b))

In the present invention, the decrease in capacity due to immobilization and antigen binding of the molecular layer is believed to be due to the continuous generation of the insulating layer. The formation of an insulating self-assembled monolayer (SAM) of APTES in rGO-ICE provides a stable insulating layer on the electrode surface (C SAM )

In addition, the binding of the insulin antibody to the electrode forms a new capacitor (C Ab - Ins ) in series with the C SAM .

BSA (Bovine Serum Albumin) acts as a blocking agent in the void space between Ab-Ins molecules.

Finally, the addition of insulin to the immobilized antibody results in the formation of additional capacitors (C insulin ) continuously.

Therefore, the immobilization of the molecular layer and the capacity reduction due to antigen binding can be expressed by the following Equation 1, which means that SAM layer formation or biomolecule immobilization is when forming series of capacitive layers. Thus, the total capacitance (C Total ) of the rGO-ICE after immobilization of the SAM layer, Ab-Ins, BSA and insulin is given by:

(Equation 1)

Figure pat00006

Experimental Example  3: Capacitance detection of insulin

Changes in rGO-ICE-based immunosensor capacity with 1 to 10,000 ng / ml insulin concentration diluted in PBS 10 mM (

Figure pat00007
) Were measured.

As the insulin concentration increased, the dose decreased. The capacity change according to the insulin concentration was analyzed by normalizing the dose according to the following equation (2).

(Equation 2)

Figure pat00008

In the above formula 2, C i and C 0 are the measured capacities according to the antigenic and non-toxic, respectively.

According to frequency (f)

Figure pat00009
Are shown in Fig. 5A. As a result, it was confirmed that insulin could be detected using rGO-ICE-based insulin sensor, and it was confirmed that insulin could be quantitatively measured.

Further, as in the result of Fig. 5A,

Figure pat00010
Was observed when frequency (f) was 4.7 kHz, from which it was selected to evaluate sensor performance with insulin interaction.

Also, for log concentrations of 1 ng / ml to 10000 ng / ml antigen (C insulin ) in PBS

Figure pat00011
The linear regression curve based on the change at 4.7 kHz is shown in FIG. 5b. Having a linear regression equation of R 2 = 0.985 y = 0.084 x + 0.240 (x: ng / ml, y:
Figure pat00012
at 4.7 kHz ).

Experimental Example  4: human serum ( human serum Detection of insulin capacity

In order to confirm the practical application possibility, the sensor was applied to various concentrations of insulin prepared from human serum (Yonsei Severance Hospital, Seoul, Korea) in the range of 1 to 10000 ng / ml. Human serum was obtained by dilution with 10 mM PBS buffer (1: 200) to avoid matrix effect.

Various concentrations of insulin were prepared from the diluted serum samples and added to the electrodes for incubation. The frequency (f) was measured, and the results are shown in FIG. 6A. Increased with the insulin concentration of human serum.

Figure pat00013
Was observed at 4.7 kHz, so that the effect of various insulin concentrations (C HS-insulin )
Figure pat00014
at 4.7 kHz are graphed in a logarithmic scale, and the results are shown in FIG. 6B.

The linear relationship between the log value of insulin concentration and the dose was confirmed in the range of 1 to 10 3 ng / ml concentration. The linear regression equation y = R 2 = 0.027 x + has a 0.012 0.981 (x: ng / ml, y:

Figure pat00015
at 4.7 kHz ), and the detection limit was 0.086 nM, which was calculated by 3 SD / S, where SD is the standard error of the slice and S is the slope of the calibration curve.

In addition, the detection limit and linear range of the immune sensor are comparable to other reported insulin sensors (Ref.), And the results are shown in Table 2 below.

Electrode Method Linear range
(nM) Detection limit
(nM) Ref. SiO 2 NPs-Nafion / GCE a DPV 10-50 2.8 [31] NiNPs / ITO CA 1-125 0.01 [32] EDA b -CNFs c -NiO CA 20-1020 12.1 [33] SPE d / MWCNT e / NiONPs f CA 20-260 6.1 [34] CNT-NiCoO 2 / Nafion CA 17.2-5430 37.93 [35] GCE / CNT CV 3.45-68.97 1.34 [36] Guanine / NiOxNPs / GCE CA 100-1000 0.022 [37] Ni (OH) 2 -GN g / GCE CA 800-6400 200 [38] rGO / ITO (invention) EIS 0.17-172.4 0.086 Invention a Glassy Carbon Electrode.
b Ethylenediamine.
c Carbon Nanofibers.
d Screen Printed Electrode.
e Multi-walled Carbon nanotube.
f Nickel Oxide Nanoparticles.
g Graphene Nanocomposite.

After application to the target-non-target protein,

Figure pat00016
, It can be seen that the sensor according to the present invention shows specificity toward the insulin detection side.

From the results of the EIS, the immune sensor maintained its bioactivity without any denaturation even after a storage period of 4 ° C for 1 week. This means that the rGO surface has biocompatibility with immobilized biomolecules do.

Claims (12)

A rGO-ICE electrode characterized in that reduced graphene oxide (rGO) is deposited on an ICD (Interdigitated Chain Electrode) electrode.
The method according to claim 1,
Wherein the reduced graphene oxide deposited on the ICE electrode is a rounded corrugated, wrinkled sheet having a chain-like structure interconnected with the rGO-ICE electrode.
Patterning an ICE electrode on the substrate,
Inserting the electrode chip of the ICE electrode, and
And depositing a reduced graphene oxide on the detection region of the ICE electrode. ≪ Desc / Clms Page number 20 >
The method of claim 3,
Wherein the ICE electrode is indium tin oxide (ITO).
The method of claim 3,
Wherein the ICE electrode chip is polydimethylsiloxane (PDMS).
The method of claim 3,
Wherein the reduced graphene oxide is deposited using chronoamperometry. ≪ RTI ID = 0.0 > 18. < / RTI >
An rGO-ICE based insulin sensor based on the rGO-ICE electrode according to claim 1.
8. The method of claim 7,
The insulin sensor comprises an insulator layer formed on the rGO-ICE electrode layer,
An antibody immobilized on the insulating layer, and
And an insulin antigen bound to said antibody.
8. The method of claim 7,
Wherein the insulating layer comprises 3-aminopropyl triethoxysilane (APTES) and the insulating layer forms a self-assembled monolayer (SAM).
8. The method of claim 7,
An rGO-ICE based insulin sensor wherein glutaraldehyde (GA) is used as a vehicle for immobilization of the antibody.
8. The method of claim 7,
Wherein the rGO-ICE-based insulin sensor is immobilized on a vacant space between the antibody and insulin molecules using BSA (Bovine Serum Albumin) as a blocking agent to prevent nonspecific adsorption to the surface of the rGO-ICE electrode layer.
forming an insulating layer on the rGO-ICE electrode layer,
Immobilizing the antibody on the insulating layer,
Immobilizing a BSA (Bovine Serum Albumin) blocking agent to prevent nonspecific adsorption onto the surface of the rGO-ICE electrode layer, and
And binding the insulin antibody to the insulin antibody to immobilize the rGO-ICE based insulin sensor.
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