KR101370724B1 - Sensor for detecting saccharides and detection method of saccharides using the same - Google Patents

Sensor for detecting saccharides and detection method of saccharides using the same Download PDF

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KR101370724B1
KR101370724B1 KR1020120008389A KR20120008389A KR101370724B1 KR 101370724 B1 KR101370724 B1 KR 101370724B1 KR 1020120008389 A KR1020120008389 A KR 1020120008389A KR 20120008389 A KR20120008389 A KR 20120008389A KR 101370724 B1 KR101370724 B1 KR 101370724B1
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심윤보
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부산대학교 산학협력단
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Abstract

본 발명은 단당류 검출용 센서 및 이를 이용한 단당류 검출방법에 관한 것으로, 상기 본 발명에 따른 센서는 pTTCA 개질 전극의 표면 상에서 존재하는 보론산과 검출하고자 하는 글루코오스와 같은 단당류 사이의 복합체 형성을 통해 효과적이면서도 안전하게 글루코오스와 같은 단당류를 검출할 수 있다.The present invention relates to a sensor for detecting a monosaccharide and a method for detecting a monosaccharide using the same, wherein the sensor according to the present invention is effective and safe through complex formation between boronic acid present on the surface of a pTTCA modified electrode and a monosaccharide such as glucose to be detected. Monosaccharides such as glucose can be detected.

Description

단당류 검출용 센서 및 이를 이용한 단당류 검출방법{Sensor for detecting saccharides and detection method of saccharides using the same}Sensor for detecting saccharides and detection method of monosaccharides using the same

본 발명은 체액 중에 존재하는 단당류를 높은 민감도로 안전하게 검출할 수 있는 단당류 검출용 센서 및 이를 이용한 단당류 검출방법에 관한 것이다.The present invention relates to a monosaccharide detection sensor capable of safely detecting monosaccharides present in body fluids with high sensitivity, and a monosaccharide detection method using the same.

단당류는 생명체에게 중요한 에너지 물질로서, 의약, 식품 및 생화학 분야에서 자주 사용된다. 따라서, 단당류의 신속하고 정확한 검출이 크게 주목을 받고 있다. 당류 검출을 위한 현재 대부분의 기술은 산화 용이성을 탐색한다. 그러나, 산화성 접근은 느린 동력학과 낮은 민감성을 야기하는 전극 독성이라는 공통적인 문제점을 초래한다. Monosaccharides are important energy substances for living things and are frequently used in medicine, food and biochemistry. Therefore, the rapid and accurate detection of monosaccharides has attracted much attention. Most current techniques for sugar detection explore the ease of oxidation. However, the oxidative approach introduces a common problem of electrode toxicity that results in slow kinetics and low sensitivity.

즉, 현재 가장 많이 사용되는 Pt를 포함한 대부분의 순수 금속은 낮은 농도의 글루코오스 검출에 만족할 만한 민감도를 나타내지 못하는 낮은 효율성과 화학흡착된 중간매개물로 인한 전극 독성과 같은 근본적인 문제점을 초래한다.That is, most of the pure metals including Pt, which are currently used most, cause fundamental problems such as low efficiency and electrode toxicity due to chemisorbed intermediates, which do not exhibit satisfactory sensitivity to detecting low concentrations of glucose.

따라서, 글루코오스 등의 단당류를 보다 신속하면서도 정확하게 검출할 수 있는 이상적인 단당류 검출용 센서의 개발이 요구되고 있다.Therefore, there is a demand for the development of an ideal monosaccharide detection sensor that can detect monosaccharides such as glucose more quickly and accurately.

이에, 본 발명자는 전기전도성 고분자와 보론산을 개질시킨 전극을 이용하여 글루코오스와 같은 단당류를 신속하면서도 정확하게 검출할 수 있다는 점을 발견하여 본 발명을 완성하였다.Accordingly, the present inventors have completed the present invention by discovering that a monosaccharide such as glucose can be detected quickly and accurately by using an electrode which is modified with an electrically conductive polymer and boronic acid.

이에, 본 발명의 목적은 신속하면서도 정확하게 글루코오스 등과 같은 단당류를 검출할 수 있는 단당류 검출용 센서 및 이를 이용한 단당류 검출방법을 제공하는 데에 있다.Accordingly, it is an object of the present invention to provide a sensor for detecting a monosaccharide which can detect monosaccharides such as glucose quickly and accurately, and a method for detecting monosaccharides using the same.

상기 목적을 달성하기 위하여, 본 발명은 전극 표면 상에 보론산 및 전도성 고분자로 개질되며, 상기 전도성 고분자가 폴리-5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)인 것을 특징으로 하는 단당류 검출용 센서를 제공한다.In order to achieve the above object, the present invention is modified with boronic acid and a conductive polymer on the electrode surface, the conductive polymer is poly-5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid ( It provides a sensor for detecting a monosaccharide, characterized in that pTTCA).

상기 보론산은 아미노-페닐보론산(APBA)일 수 있지만, 이에 한정되는 것은 아니다.The boronic acid may be amino-phenylboronic acid (APBA), but is not limited thereto.

본 발명에 따른 센서는 pTTCA로 개질된 전극의 표면 상에서 보론산과 글루코오스 등의 단당류 간의 복합체 형성 반응을 통해 글루코오스 등과 같은 단당류를 민감하면서도 효율좋게 검출할 수 있다.The sensor according to the present invention can sensitively and efficiently detect monosaccharides such as glucose through complex formation reaction between boronic acid and monosaccharides such as glucose on the surface of the electrode modified with pTTCA.

또한, 본 발명은 전위주사를 통해 5,2':5',2"-터티오펜-3'-카르복실산(TTCA) 단량체를 전해중합시켜 전극 표면을 폴리 5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)로 개질하는 단계; 상기 pTTCA로 개질된 전극에 EDC(1-Ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride) 및 NHS(N-hydroxysuccinimide)을 처리하여 pTTCA의 카르복실기를 활성화시키는 단계; 및 상기 활성화된 pTTCA 전극에 보론산을 반응시켜 TTCA의 카르복실기와 보론산의 아민기 간의 공유결합을 형성시키는 단계를 포함하는 것을 특징으로 하는 단당류 검출용 센서의 제조방법을 제공한다.In addition, the present invention provides a poly 5,2 ': 5', 2 electrolytic polymerization of 5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (TTCA) monomer through potential injection. Modifying with “-terthiophene-3′-carboxylic acid (pTTCA); Treating the pTTCA-modified electrode with EDC (1-Ethyl-3- [3- (dimethylamino) propyl] carbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) to activate a carboxyl group of pTTCA; And reacting boron acid to the activated pTTCA electrode to form a covalent bond between the carboxyl group of TTCA and the amine group of boronic acid.

또한, 본 발명은 전극 표면 상에 보론산 및 전도성 고분자로 개질되며, 상기 전도성 고분자가 폴리-5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)인 단당류 검출용 센서를 이용한 단당류 검출방법을 제공한다.In addition, the present invention is modified with boronic acid and a conductive polymer on the electrode surface, the monosaccharide detection that the conductive polymer is poly-5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (pTTCA) Provided is a monosaccharide detection method using a sensor.

상기 단당류는 글루코오스, 갈락토오스, 만노오스, 푸코오스, 자일로오스 및 프락토오스로 이루어진 군에서 선택될 수 있지만, 이에 한정되는 것은 아니며 단당류라면 어떠한 것이라도 본 발명에 따른 센서를 이용하여 검출 가능하다.The monosaccharide may be selected from the group consisting of glucose, galactose, mannose, fucose, xylose and fructose, but is not limited thereto, and any monosaccharide can be detected using the sensor according to the present invention.

특히, 상기 단당류 검출을 위한 실험 파라미터로서 용액 pH, 반응시간, APBA 농도 및 반응온도를 최적화하는 것이 중요하며, 최적 pH를 pH 7.4, 최적 온도를 40℃, APBA 최적 농도를 20.0 mM 및 최적 반응시간을 5분으로 하여 단당류 검출을 수행한 경우 가장 효율좋게 단당류를 검출할 수 있었다.
In particular, it is important to optimize the solution pH, reaction time, APBA concentration and reaction temperature as experimental parameters for detecting the monosaccharides. When monosaccharide detection was performed at 5 minutes, monosaccharides could be detected most efficiently.

이하, 일실시예를 통해 본 발명을 보다 상세하게 설명한다.Hereinafter, the present invention will be described in more detail with reference to one embodiment.

전도성 고분자인 5,2':5',2"-터티오펜-3'-카르복실산(TTCA)과 단당류 리셉터로 사용되는 3-아미노페닐보론산(APBA)을 이용하여 단당류 검출용 센서를 제작할 수 있다. 이러한 단당류 검출용 센서를 제작하기 위하여, 먼저 TTCA를 전기화학적으로 중합하여 탄소 유리 전극(CGE) 위에 전착 후, 전도성 고분자의 카르복실기와 APBA의 아민기 사이에 공유결합을 통하여 CGE 위에 고정시킨다. A sensor for detecting monosaccharides can be fabricated using 5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (TTCA), a conductive polymer, and 3-aminophenylboronic acid (APBA) used as a monosaccharide receptor. In order to fabricate such a monosaccharide detection sensor, TTCA is first electrochemically polymerized and deposited on a carbon glass electrode (CGE), and then fixed on the CGE through a covalent bond between the carboxyl group of the conductive polymer and the amine group of the APBA. .

이렇게 제조된 단당류 검출용 센서 표면의 특성은 순환 전류 전압법(cyclic voltammetry, CV), X-선 광전자 분광법(X-ray photoelerectron spectroscopy, XPS), 그리고 미세 진동 저울(quartz crystal microbalance, QCM)을 이용하여 조사하였으며, 펄스 차이 전압 전류법 (differential pulse voltammetry, DPV)을 이용하여 글루코오스를 검출하였다.The surface characteristics of the monosaccharide detection sensor were fabricated using cyclic voltammetry (CV), X-ray photoelerectron spectroscopy (XPS), and quartz crystal microbalance (QCM). Glucose was detected using differential pulse voltammetry (DPV).

그 결과, TTCA와 APBA를 이용해 성공적으로 단당류 검출 센서를 개발할 수 있었으며, 전극 위에 결합된 글루코오스와 APBA의 양은 QCM 분석을 통해 각각 0.89 ㎍ (2.93 X 10-8 mol/cm2)과 0.24 ㎍ (6.85 X 10-9 mol/cm2)인 것을 확인하였다. 또한, 펄스 차이 전압 전류법(differential pulse voltammetry, DPV)을 사용한 결과, 글루코오스의 유효 측정 농도 범위는 0.9 ~ 9.1 μM이었고 검출 한계는 0.49 μM이었다. 그리고 표준물 첨가법을 이용하여 실제시료 즉, 사람 타액의 글루코오스의 농도 분석 (0.261 ± 0.001 mM)에 적용할 수 있었다.As a result, we successfully developed monosaccharide detection sensors using TTCA and APBA, and the amounts of glucose and APBA bound on the electrodes were 0.89 ㎍ (2.93 X 10 -8 mol / cm 2 ) and 0.24 ㎍ (6.85), respectively, by QCM analysis. X 10 -9 mol / cm 2 ) was confirmed. In addition, as a result of using differential pulse voltammetry (DPV), the effective measurement concentration range of glucose was 0.9 to 9.1 μM and the detection limit was 0.49 μM. Using the standard addition method, it could be applied to the actual sample, ie, human saliva glucose concentration analysis (0.261 ± 0.001 mM).

본 발명에 따른 센서는 pTTCA 개질 전극의 표면 상에서 존재하는 보론산과 검출하고자 하는 글루코오스와 같은 단당류 사이의 복합체 형성을 통해 효과적이면서도 안전하게 글루코오스와 같은 단당류를 검출할 수 있다. The sensor according to the present invention can effectively and safely detect monosaccharides such as glucose through complex formation between boronic acid present on the surface of the pTTCA modified electrode and monosaccharides such as glucose to be detected.

도 1은 pTTCA (점선)와 APBA/pTTCA (실선)의 순환전류전압 곡선 (용액: PBS (pH 7.4), 주사속도: 100 mV/s),
도 2는 각 변성 단계 (pTTCA, APBA/pTTCA)에서의 XPS 스펙트럼 ((A) C1s, (B) N1s, (C) S2p, (D) B1s),
도 3은 QCM을 이용하여 전극에 전착되는 APBA와 글루코오스의 양에 따른 진동수 변화 측정,
도 4는 실험 조건에 대한 최적화 ((A) pH, (B) 온도, (C) APBA의 농도, (D) 글루코오스와 반응시간),
도 5 중 A는 글루코오스 농도에 대한 검정선, B는 다른 종류의 단당류 (글루코오스, 갈락토오스, 만노오스) 농도에 대한 검정선,
도 6은 실제 사람 타액 속에 존재하는 글루코오스 농도 검출 분석을 나타낸 것이다.
1 is a cyclic current voltage curve of pTTCA (dotted line) and APBA / pTTCA (solid line) (solution: PBS (pH 7.4), scanning speed: 100 mV / s),
Figure 2 shows the XPS spectra in each denaturation step (pTTCA, APBA / pTTCA) ((A) C1s, (B) N1s, (C) S2p, (D) B1s),
3 is a measurement of the frequency change according to the amount of APBA and glucose electrodeposited to the electrode using QCM,
4 shows optimization for experimental conditions ((A) pH, (B) temperature, (C) APBA concentration, (D) glucose and reaction time),
In FIG. 5, A is a calibration line for glucose concentration, B is a calibration line for concentrations of other monosaccharides (glucose, galactose, and mannose),
Figure 6 shows the detection of glucose concentration present in real human saliva.

이하, 하기 실시예에 의해 본 발명을 보다 상세하게 설명한다. 다만, 이러한 실시예에 의해 본 발명이 한정되는 것은 아니다.
Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

<실시예 1> 개질 전극 제작&Lt; Example 1 > Preparation of modified electrode

100 m/Vs의 주사속도에서 0.0 내지 1.5V (vs. Ag/AgCl)로 2회 전위주사를 통해 CH2Cl2 용액을 함유한 1.0 mM TTCA(5,2':5,2"-terthiophen-3'-carboxylic acid)를 전해중합시켜 전극 표면을 개질하였다. 이때, 사용된 TTCA 단량체는 이전에 알려진 방법(Synth. Met., 126, 105, 2002)에 따라 합성하였다. 이렇게 얻어진 pTTCA이 코팅된 전극을 10.0 mM EDC(1-Ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride) 및 10.0 mM NHS(N-hydroxysuccinimide)의 혼합물을 함유한 0.1M PBS(pH 7.4)에 최소 6시간 동안 담구어 pTTCA의 카르복실기를 활성화시켰다. 이러한 pTTCA 전극을 40℃에서 15 시간 동안 20.0 mM APBA(Amino-phenylboronic acid) 용액에서 반응시켜 TTCA의 카르복실기와 보론산의 아민기 간의 공유결합을 형성시켰다. 그후, 0.1M PBS에서 철저하게 세정한 후, 이후 실험에 사용하였다.
1.0 mM TTCA (5,2 ': 5,2 "-terthiophen- containing a solution of CH 2 Cl 2 via two potential injections at 0.0 to 1.5 V (vs. Ag / AgCl) at a scanning rate of 100 m / Vs. 3'-carboxylic acid) was electropolymerized to modify the electrode surface, wherein the TTCA monomers used were synthesized according to previously known methods ( Synth. Met. , 126, 105, 2002). The electrode is immersed in 0.1M PBS pH 7.4 containing a mixture of 10.0 mM EDC (1-Ethyl-3- [3- (dimethylamino) propyl] carbodiimide hydrochloride) and 10.0 mM NHS (N-hydroxysuccinimide) for at least 6 hours. The carboxyl group of pTTCA was activated, and this pTTCA electrode was reacted in a 20.0 mM amino-phenylboronic acid (APBA) solution at 40 ° C. for 15 hours to form a covalent bond between the carboxyl group of TTCA and the amine group of boronic acid. After thoroughly washing in M PBS, it was used for later experiments.

<실시예 2> 전기화학적 분석&Lt; Example 2 > Electrochemical analysis

1. 전기화학적 분석 방법1. Electrochemical analysis method

APBA-pTTCA, Ag/AgCl(in 포화 KCl) 및 Pt를 각각 작업적극, 표준전극 및 반대전극으로 사용하였다. 순환 전압전류(cyclic voltammogram; CV)는 Potentiostat/Galvanostat(모델: KST-P2, Kosentech)를 이용하여 측정하였으며, 펄스 차이 전압 전류(differential pulse voltammetry, DPV)는 10 m/Vs의 주사속도에서 -100 mV에서 350 mV의 전위에서 주사시켜 얻었다. 모든 전기화학적 측정은 0.1M PBS(pH 7.4)에서 수행되었다. 미세 진동 저울(Quartz Crystal Microbalance; QCM) 분석은 SEIKO EG&G 모델 QCA 917 및 PAR 모델 263A potentiostat/galvanostat을 수행하였으며, QCM 분석을 위하여 Au 작동전극(면적 0.196 cm-2; 9 MHz; AT-cut quartz crystal)을 이용하였다. XPS 분석은 VG Scientific Escalab 250 XPS 분광계[단색화된 Al Kα 광원 (KBSI Busan, Korea)]를 이용하여 수행하였다. APBA-pTTCA, Ag / AgCl (in saturated KCl) and Pt were used as working positive electrode, standard electrode and counter electrode, respectively. Cyclic voltammogram (CV) was measured using Potentiostat / Galvanostat (model: KST-P2, Kosentech), and differential pulse voltammetry (DPV) was -100 at a scan rate of 10 m / Vs. It was obtained by scanning at an electric potential of mV to 350 mV. All electrochemical measurements were performed in 0.1 M PBS, pH 7.4. Quartz crystal microbalance (QCM) analysis was performed on SEIKO EG & G model QCA 917 and PAR model 263A potentiostat / galvanostat. For QCM analysis, Au working electrode (area 0.196 cm -2 ; 9 MHz; AT-cut quartz crystal ) Were used. XPS analysis was performed using a VG Scientific Escalab 250 XPS spectrometer (monochromed Al Kα light source (KBSI Busan, Korea)).

2. 전기화학적 분석 결과2. Electrochemical analysis results

1) APBA 개질 pTTCA의 전기화학적 특성1) Electrochemical Properties of APBA Modified pTTCA

보론산이 고정된 전극의 전기화학적 거동을 순환 전압전류(CV) 분석을 통해 검토한 결과, 도 1에 도시된 바와 같이 한쌍의 잘 구별되는 준가역적 산화환원 피크가 0.16V/0.07V (vs. Ag/AgCl)에서 나타났으며, 피크의 높이 비 I pa/I pc ≒ 1.2로 나타났다. E paE pc의 중간지점으로 산출된 형식 전위(')는 대략 +0.09V (vs. Ag/AgCl)이었다. 한편, 이러한 전위 영역에서 pTTCA로 개질된 유리탄소전극(GCE)에서는 어떠한 전압전류 피크도 나타나지 않았다. Electrochemical behavior of boron acid-fixed electrodes was examined by cyclic voltammetry (CV) analysis, and as shown in FIG. 1, a pair of well-recognized quasi-reversible redox peaks of 0.16 V / 0.07 V (vs. Ag) / AgCl), the peak height ratio I pa / I pc ≒ 1.2. The formal potential ( E ° ') calculated as the midpoint of E pa and E pc was approximately +0.09 V (vs. Ag / AgCl). On the other hand, no voltage or current peak was observed in the glass carbon electrode (GCE) modified with pTTCA in this potential region.

산화환원 반응의 특성을 탐색하기 위하여, 산화환원 공정의 거정을 다양한 pH 값에서 관찰한 결과, 형식 전위(')는 5 내지 9의 pH에서 선형을 나타냈으며, '과 pH 간의 그래프에서 기울기는 -50 mV/pH로 산출되었고, 이는 이론상의 산출값인 -59 mV/pH와 유사하였다. 50-200 mV/s의 주사속도에서 APBA 개질 pTTCA의 전기화학적 반응은 모두 준가역적 공정을 나타내었다. 주사속도가 증가함에 따라 환원피크는 음의 값으로 이동하고, 산화피크는 양의 값으로 이동하였다. 그리고, Laviron 식에서 E p, △E p 및 logν의 상관관계로부터 α, n 및 k s 값을 각각 0.7, 1 및 0.4 s-1로 산출하였다. 이러한 결과로부터 산화환원 공정은 APBA에 존재하는 아미노기의 1 전자와 1 프로톤 교환과 관련되는 것으로 추정되었다.In order to explore the properties of the redox reactions, observations of redox processes at various pH values showed that the formal potential ( E ° ') was linear at a pH between 5 and 9, and the graph between E ° ' and pH The slope at was calculated to be -50 mV / pH, which is similar to the theoretical calculation of -59 mV / pH. All electrochemical reactions of APBA modified pTTCA at a scan rate of 50-200 mV / s showed a semi-reversible process. As the scanning speed increased, the reducing peak moved to a negative value, and the oxide peak moved to a positive value. In the Laviron equation, α, n, and k s values were calculated as 0.7, 1, and 0.4 s −1 , respectively, from the correlation of E p , Δ E p, and logν. From these results, it was estimated that the redox process involves one electron and one proton exchange of the amino groups present in APBA.

2) APBA 개질 pTTCA에서의 XPS 및 QCM 분석 결과 2) XPS and QCM Analysis Results in APBA Modified pTTCA

APBA 개질 pTTCA에서의 화학적 결합을 규명하기 위하여, pTTCA 및 APBA 개질 pTTCA의 표면에 대한 C1s (도 2A), N1s (도 2B), S2p (도 2C) 및 B1s (도 2D) 피크에서 ESCA 분석을 수행한 결과, pTTCA에 관한 C1s 스펙트럼은 284.1 eV 및 287.0 eV의 2개 피크로 나타났고, 이는 각각 C-C, C-H 또는 C-S 결합과 C00H 결합에 대응한다. APBA-pTTCA에 관한 285.6 eV에서 관찰된 피크는 APBA의 C-N 결합에 대응한다. N1s 스펙트럼에서는 APBA 고정 후 399.2 eV 근처에서 분명한 피크가 나타난 반면, pTTCA층은 분자 내에 질소 원자가 존재하지 않아 어떠한 피크도 나타나지 않았다. 또한, S2p 스펙트럼엥서는 163.8 eV의 피크가 나타났으며, 이는 C-S 결합에 대응한다. B1s 스펙트럼은 190.2 eV에서 피크가 나타났으며, C-B 결합에 대응한다. 이러한 결과로부터 APBA는 pTTCA 층에 성공적으로 고정화되었음을 알 수 있다.To characterize chemical binding in APBA modified pTTCA, ESCA analysis was performed on C1s (FIG. 2A), N1s (FIG. 2B), S2p (FIG. 2C) and B1s (FIG. 2D) peaks on the surface of pTTCA and APBA modified pTTCA. As a result, the C1s spectrum for pTTCA appeared with two peaks of 284.1 eV and 287.0 eV, corresponding to CC, CH or CS bonds and C00H bonds, respectively. The peak observed at 285.6 eV for APBA-pTTCA corresponds to the C-N binding of APBA. The N1s spectrum showed a clear peak near 399.2 eV after APBA fixation, whereas the pTTCA layer did not show any peaks due to the absence of nitrogen atoms in the molecule. In addition, the S2p spectrum encoder showed a peak of 163.8 eV, which corresponds to C-S binding. The B1s spectrum peaked at 190.2 eV and corresponds to C-B binding. These results indicate that APBA was successfully immobilized on the pTTCA layer.

또한, 글루코오스와 보론산 유도체의 복합체를 조사하기 위하여, 탐침 표면에서 발생하는 질량 변화를 QCM 분석을 통해 조사하였다. 도 3은 글루코오스를 첨가할 경우의 진동수 변화를 나타낸 것으로, pTTCA 층 상에 고정된 보론산의 양은 약 0.81 kHz의 진동수 변화로부터 0.89 ㎍인 것으로 결정되었다. APBA에 의한 표면 범위는 2.93 X 10-8 mol/cm2인 것으로 산출되었다. APBA-pTTCA 개질 전극을 0.1M PBS (pH 7.4) 중 1.0 mM 글루코오스 함유 QCM 셀에 담구었고, 보론산과 글루코오스 간의 복합체 형성을 가리키는 약 10분 내에 안정기로 도달할 때가지 진동수는 감소되었다. 전체 진동수 변화(△f)는 1.0 mM의 글루코오스에 관한 0.24 ㎍의 질량 증가에 대응하는 0.22 kHz로 나타났다. 1.0 mM 글루코오스에 의한 표면 범위는 6.85 X 10-9 mol/cm2인 것으로 산출되었다. In addition, to investigate the complex of glucose and boronic acid derivatives, the mass change occurring on the surface of the probe was investigated by QCM analysis. Figure 3 shows the frequency change when glucose is added, and the amount of boronic acid fixed on the pTTCA layer was determined to be 0.89 μg from the frequency change of about 0.81 kHz. The surface range by APBA was calculated to be 2.93 × 10 −8 mol / cm 2 . The APBA-pTTCA modified electrode was immersed in a QCM cell containing 1.0 mM glucose in 0.1 M PBS (pH 7.4), and the frequency was reduced until reaching the plateau within about 10 minutes indicating the complex formation between boronic acid and glucose. The total frequency change (Δf) was found to be 0.22 kHz corresponding to a mass increase of 0.24 μg for 1.0 mM glucose. The surface range with 1.0 mM glucose was calculated to be 6.85 × 10 −9 mol / cm 2 .

3) 분석용 실험 파라미터의 최적화3) Optimization of Experimental Parameters for Analysis

APBA-pTTCA를 갖는 글루코오스 검출을 위한 실험 파라미터로서 용액 pH, 반응시간, APBA 농도 및 반응온도를 최적화하기 위해 실험을 수행하였다. Experiments were performed to optimize solution pH, reaction time, APBA concentration and reaction temperature as experimental parameters for glucose detection with APBA-pTTCA.

글루코오스 검출에 있어 pH의 영향은 1.0 mM 글루코오스 함유 0.1M PBS(pH 7.4) 상에서 pH 5-9의 범주에서 조사하였다. 도 4A와 같이, 블랭크와 비교하여 산화 전류의 감소는 pH 5.0에서 pH 7.4로 변화하면서 증가한 후, pH 7.4보다 높은 경우 점차적으로 감소하였다. 따라서, 최적 pH로서 pH 7.4를 선정하였다.The effect of pH on glucose detection was investigated in the range of pH 5-9 on 1.0 mM glucose containing 0.1 M PBS pH 7.4. As shown in Figure 4A, the decrease in oxidation current compared to the blank increased with a change from pH 5.0 to pH 7.4 and then gradually decreased when higher than pH 7.4. Therefore, pH 7.4 was chosen as the optimal pH.

또한, 글루코오스 검출에 있어 온도의 영향은 20℃ 내지 60℃에서 관찰한 결과, 도 4B와 같이 40℃의 온도까지는 전류 반응이 증가하며, 그 이후에는 점차적으로 감소하였다. 따라서, 글루코오스 검출을 위한 최적 온도는 40℃로서 선정하였다. In addition, the effect of temperature on glucose detection was observed at 20 ℃ to 60 ℃, as shown in Figure 4B the current response to the temperature of 40 ℃ increased, and then gradually decreased. Therefore, the optimum temperature for glucose detection was chosen as 40 ° C.

또한, 글루코오스 검출에 있어 APBA 농도의 영향을 검토한 결과, 도 4C와 같이 APBA의 농도가 20.0 mM일 경우 가장 효율좋게 글루코오스를 검출할 수 있었다.As a result of examining the influence of APBA concentration on glucose detection, glucose was most efficiently detected when the concentration of APBA was 20.0 mM as shown in FIG. 4C.

또한, 글루코오스 검출에 있어 반응시간의 영향을 검토한 결과, 도 4D와 같이 최적 반응시간은 5분으로 확인되었다.In addition, as a result of examining the influence of the reaction time on the detection of glucose, as shown in FIG. 4D, the optimum reaction time was confirmed as 5 minutes.

4) 단당류 검출4) Monosaccharide Detection

개질 전극의 거동을 테스트 용액 중에 글루코오스를 첨가하거나 첨가하지 않은 경우로 나누어 분석하였다. 먼저, 안정한 전압전류를 얻을 때까지 전압전류를 -0.2V에서 0.4V의 범위 내에서 0.1M PBS (pH 7.4)에서 기록하였다. 그후, 글루코오스를 각 용액에 첨가한 후, 전압전류를 측정하였다. 글루코오스의 첨가는 APBA 개질 GCE의 산화환원 전위에는 영향을 미치지 않았다. 그러나, 글루코오스의 농도가 증가할 때 약 0.2V에서 음극성 피크의 유도 전류가 분명하게 감소되었다. The behavior of the modified electrode was analyzed by dividing the case with or without glucose in the test solution. First, the voltage current was recorded in 0.1M PBS (pH 7.4) in the range of -0.2V to 0.4V until a stable voltage current was obtained. Then, glucose was added to each solution, and then the voltammogram was measured. The addition of glucose did not affect the redox potential of the APBA modified GCE. However, as the concentration of glucose increased, the induced current of the negative peak was clearly reduced at about 0.2V.

글루코오스 첨가와 함께 산화피크 전류 변화를 모니터링하기 위하여, DPV를 기록하였다. 도 5의 삽입도는 -0.10V에서 0.35V의 전압 범위에서 글루코오스 첨가 및 미첨가에 따른 음극성 주기에서 DPV를 나타낸다. 이는 전극 표면 상에 글루코오스의 직접적 산화가 이러한 전위 영역에서 발생하지 않았기 때문이다. 보론산기에 결합한 글루코오스의 디올기는 음전화를 띤 테트라헤드럴 브로네이트 에스테르를 형성하여 개질 전극의 전기화학적 반응에 영향을 미친다. In order to monitor the peak current of oxidation with glucose addition, DPV was recorded. The inset of FIG. 5 shows DPV in the negative period with glucose addition and no addition in the voltage range of -0.10V to 0.35V. This is because direct oxidation of glucose on the electrode surface did not occur in this potential region. Diol groups of glucose bound to boronic acid groups form negatively charged tetrahedral bronate esters which affect the electrochemical reaction of the modified electrode.

도 5A는 최적 조건에서 글루코오스 검출을 위한 DPV 측정으로부터 얻어진 산출 그래프이다. 도 5A의 삽입도는 계속적인 글루코오스 첨가에 따른 APBA-pTTCA 개질 전극 상에서 얻어진 전압전류 그래프이다. 이러한 결과로부터 개질 전극은 0.9 μM 내지 9.1 μM 사이의 농도에서 동적 범위를 나타냄을 알 수 있다. 글루코오스 농도의 선형 의존도로부터 회귀식 △i p (nA) = (10.50±1.13)+(2.41±0.20) [C] (μM)과 상관계수 0.974를 얻었다. 글루코오스 검출 한계는 5개의 블랭크 노이즈 신호로부터 0.45 μM로서 결정하였다(95% 신뢰도, k=3). 상기 개질 전극의 재현성은 상대표준편차(RSD)로서 표현컨대 1.0 μM의 글루코오스 농도에서 3.8%로 나타났다. 이러한 결과로부터, 본 글루코오스 센서는 높은 민감성과 안정성을 나타냄을 알 수 있다. 측정 후, 개질 전극을 0.1M PBS에 담구어 다시 복원시켰다. 4 ℃에서 완충액에 저장할 경우 센서는 한달 동안 글루코오스 검출에 대한 반응의 92% 이상으로 유지되었다. 도 5B는 최적 조건 하에서 글루코오스, 갈락토오스 및 만노오스 검출을 위한 DPV 측정으로부터 얻어진 산출 그래프로서, 갈락토오스 및 만노오스 농도의 선형 의존도로부터 각각 회귀식 △i p (nA) = (10.09±1.08)+(2.40±0.18) [C] (μM)과 상관계수 0.970, 및 회귀식 △i p (nA) = (1.49±0.62)+(2.02±0.11) [C] (μM)과 상관계수 0.989를 얻었다. 5A is a calculation graph obtained from DPV measurements for glucose detection at optimal conditions. The inset of FIG. 5A is a voltammetric graph obtained on an APBA-pTTCA modified electrode with continuous glucose addition. From these results it can be seen that the modified electrode exhibits a dynamic range at concentrations between 0.9 μM and 9.1 μM. From the linear dependence of glucose concentration, the regression equation Δ i p (nA) = (10.50 ± 1.13) + (2.41 ± 0.20) [C] (μM) and a correlation coefficient of 0.974 were obtained. Glucose detection limit was determined as 0.45 μM from five blank noise signals (95% confidence, k = 3). The reproducibility of the modified electrode was expressed as a relative standard deviation (RSD) of 3.8% at a glucose concentration of 1.0 μM. From these results, it can be seen that the glucose sensor exhibits high sensitivity and stability. After the measurement, the modified electrode was immersed in 0.1 M PBS and restored. When stored in buffer at 4 ° C., the sensor remained at least 92% of the response to glucose detection for one month. FIG. 5B is a graph of the results obtained from DPV measurements for glucose, galactose and mannose detection under optimal conditions, where the regression Δ i p (nA) = (10.09 ± 1.08) + (2.40 ± 0.18), respectively, from the linear dependence of galactose and mannose concentrations. ) A correlation coefficient 0.970 and a regression equation Δ i p (nA) = (1.49 ± 0.62) + (2.02 ± 0.11) [C] (μM) and a correlation coefficient of 0.989 were obtained.

5) 실제 시료 분석5) Real sample analysis

본 실시예에 따른 APBA-pTTCA 센서를 이용하여 건장한 인간 타액 시료에서의 단당류 농도를 검출하였다. 타액 시료는 측정 직전에 조심스럽게 수집하여 100배 희석하여 사용하였다. 표준첨가법에 따라 시료 중 단당류 농도를 표준첨가 곡선으로부터 결정하였다. 희석 시료에서는 글루코오스 함량이 2.61±0.01 μM로 나타났다. 따라서, 인간 타액 중 단당류 농도는 0.261±0.001 mM인 것으로 확인되었다. 그러므로, 본 발명에 따른 센서는 체액에서 단당류 검출을 위한 훌륭한 도구로서 사용될 수 있다.
Monosaccharide concentrations in healthy human saliva samples were detected using the APBA-pTTCA sensor according to this example. Saliva samples were collected carefully before use and diluted 100-fold. The monosaccharide concentration in the sample was determined from the standard addition curve according to the standard addition method. In the diluted samples, the glucose content was 2.61 ± 0.01 μM. Therefore, the monosaccharide concentration in human saliva was found to be 0.261 ± 0.001 mM. Therefore, the sensor according to the invention can be used as an excellent tool for the detection of monosaccharides in body fluids.

이상과 같이, 본 발명은 비록 한정된 실시예와 도면에 의해 설명되었으나, 본 발명은 이것에 의해 한정되지 않으며 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자에 의해 본 발명의 기술 사상과 아래에 기재될 청구범위의 균등 범위 내에서 다양한 수정 및 변형이 가능함은 물론이다. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various modifications and changes may be made without departing from the scope of the appended claims.

Claims (5)

전극 표면 상에 아미노-페닐보론산(APBA) 및 전도성 고분자로 개질되며, 상기 전도성 고분자가 폴리-5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)인 것을 특징으로 하는 글루코오스 검출용 센서.Modified with amino-phenylboronic acid (APBA) and a conductive polymer on the electrode surface, wherein the conductive polymer is poly-5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (pTTCA) Glucose detection sensor characterized in that. 삭제delete 전위주사를 통해 5,2':5',2"-터티오펜-3'-카르복실산(TTCA) 단량체를 전해중합시켜 전극 표면을 폴리 5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)로 개질하는 단계;
상기 pTTCA로 개질된 전극에 EDC(1-Ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride) 및 NHS(N-hydroxysuccinimide)을 처리하여 pTTCA의 카르복실기를 활성화시키는 단계; 및
상기 활성화된 pTTCA 전극에 아미노-페닐보론산(APBA)을 반응시켜 TTCA의 카르복실기와 아미노-페닐보론산(APBA)의 아민기 간의 공유결합을 형성시키는 단계
를 포함하는 것을 특징으로 하는 글루코오스 검출용 센서의 제조방법.
Electrodepolymerization of 5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (TTCA) monomers via potential injection results in poly 5,2 ': 5', 2" -terthiophene- Modifying with 3′-carboxylic acid (pTTCA);
Treating the pTTCA-modified electrode with EDC (1-Ethyl-3- [3- (dimethylamino) propyl] carbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) to activate a carboxyl group of pTTCA; And
Reacting the activated pTTCA electrode with amino-phenylboronic acid (APBA) to form a covalent bond between the carboxyl group of TTCA and the amine group of amino-phenylboronic acid (APBA)
Method of manufacturing a sensor for detecting glucose comprising a.
전극 표면 상에 아미노-페닐보론산(APBA) 및 전도성 고분자로 개질되며, 상기 전도성 고분자가 폴리-5,2':5',2"-터티오펜-3'-카르복실산(pTTCA)인 글루코오스 검출용 센서를 이용한 글루코오스 검출방법.Glucose modified with amino-phenylboronic acid (APBA) and a conductive polymer on the electrode surface, wherein the conductive polymer is poly-5,2 ': 5', 2 "-terthiophene-3'-carboxylic acid (pTTCA) Glucose detection method using a sensor for detection. 삭제delete
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