Ning Yan-Na, Xiao Bao-Lin, Niu Nan-Nan, Moosavi-Movahedi Ali Akbar, Hong Jun
School of Life Sciences, Henan University, JinMing Road, Kaifeng 475000, China.
Institute of Biochemistry and Biophysics, University of Tehran, Enquelab Avenue, Tehran 1417614418, Iran.
Polymers (Basel). 2019 Jan 11;11(1):115. doi: 10.3390/polym11010115.
In the present study, a glucose oxidase (GluOx) direct electron transfer was realized on an aminated polyethylene glycol (mPEG), carboxylic acid functionalized multi-walled carbon nanotubes (fMWCNTs), and ionic liquid (IL) composite functional polymer modified glassy carbon electrode (GCE). The amino groups in PEG, carboxyl groups in multi-walled carbon nanotubes, and IL may have a better synergistic effect, thus more effectively adjust the hydrophobicity, stability, conductivity, and biocompatibility of the composite functional polymer film. The composite polymer membranes were characterized by cyclic voltammetry (CV), ultraviolet-visible (UV-Vis) spectrophotometer, fluorescence spectroscopy, electrochemical impedance spectroscopy (EIS), and transmission electron microscopy (TEM), respectively. In 50 mM, pH 7.0 phosphate buffer solution, the formal potential and heterogeneous electron transfer constant (k) of GluOx on the composite functional polymer modified GCE were -0.27 V and 6.5 s, respectively. The modified electrode could recognize and detect glucose linearly in the range of 20 to 950 μM with a detection limit of 0.2 μM. The apparent Michaelis-Menten constant (K) of the modified electrode was 143 μM. The IL/mPEG-fMWCNTs functional polymer could preserve the conformational structure and catalytic activity of GluOx and lead to high sensitivity, stability, and selectivity of the biosensors for glucose recognition and detection.
在本研究中，葡萄糖氧化酶（GluOx）在胺化聚乙二醇（mPEG）、羧酸官能化多壁碳纳米管（fMWCNTs）和离子液体（IL）复合功能聚合物修饰的玻碳电极（GCE）上实现了直接电子转移。聚乙二醇中的氨基、多壁碳纳米管中的羧基和离子液体可能具有更好的协同效应，从而更有效地调节复合功能聚合物膜的疏水性、稳定性、导电性和生物相容性。分别采用循环伏安法（CV）、紫外可见（UV-Vis）分光光度计、荧光光谱、电化学阻抗谱（EIS）和透射电子显微镜（TEM）对复合聚合物膜进行了表征。在50 mM、pH 7.0的磷酸盐缓冲溶液中，GluOx在复合功能聚合物修饰的玻碳电极上的形式电位和异相电子转移常数（k）分别为-0.27 V和6.5 s。修饰电极能够在20至950 μM的范围内对葡萄糖进行线性识别和检测，检测限为0.2 μM。修饰电极的表观米氏常数（K）为143 μM。离子液体/聚乙二醇-多壁碳纳米管功能聚合物能够保持葡萄糖氧化酶的构象结构和催化活性，并使生物传感器对葡萄糖识别和检测具有高灵敏度、稳定性和选择性。
