本文采用一步法制备了1-芘丁酸/石墨烯复合物(PBA/G),并研究了它的电化学性质.采用铁氰化钾和亚铁氰化钾电化学探针测定了其电化学阻抗滴定曲线,确定了PBA/G的表观pKa为6.2.此外,将葡萄糖氧化酶(GOD)共价键合在PBA/G表面构建了葡萄糖电化学传感器,其电化学响应与葡萄糖浓度(5 mmol.L-1浓度范围内)呈线性关系,检测限为0.085 mmol.L-1.实验还测定了固定在PBA/G表面的GOD的表观米氏常数为5.40mmol.L-1,表明固定化的GOD对葡萄糖有较高的催化活性.
The electrochemical properties of 1-pyrenebutyric acid/graphene composites (PBA/G) obtained by one-step synthesis via π-π stacking was investigated.The electrochemical impedance titration curve shows the surface charge changes as function of solution pH by using ferricyanide/ferrocyanide redox couple as the probe.An apparent pK a value is estimated as 6.2 according to the impedance titration curve.In addition,a glucose biosensor was constructed by immobilizing glucose oxidase (GOD) on the surface of PBA/G via covalent interaction.This biosensor shows a linear response to glucose within the concentration up to 5 mmol.L -1 with a detection limit of 0.085 mmol.L -1 .A small apparent Michaelis-Menten constant (5.40 mmol.L -1 ) of the immobilized GOD suggests that the immobilized GOD retains its bioactivity and shows high catalytic activity to glucose.