电化学共沉积法制备金-壳聚糖纳米复合膜修饰电极及其在免疫传感器中的应用

The preparation of nano-gold/chitosan hybrid film by electrochemical co-deposited and its application as immunosensor

采用电化学法,在低电位下壳聚糖与氯金酸混合为电解液,直接共沉积,制备出金-壳聚糖纳米复合膜修饰的电极.实验考查了壳聚糖与氯金酸质量比对金-壳聚糖纳米复合膜形貌的影响、不同沉积时间对其形貌的影响及不同沉积电位对复合膜的活性表面积的影响.并用此复合膜成功固定了人类绒毛膜促性腺激素抗体,研制成无电子媒介的人类绒毛膜促性腺激素免疫传感器.通过电化学交流阻抗、循环伏安法和计时电流法研究免疫传感器的制作过程和电化学特性.考察了电极修饰过程中的抗原、抗体培育时间、pH值、温度等条件对传感器性能的影响.该传感器在人类绒毛膜促性腺激素为0.2～100mIU/mL的范围内有良好的线性关系,检测下限为0.1mIU/mL.

Nano-gold and chitosan hybrid film has been synthesized by direct electrodeposition with the solution of chitosan and HAuCl4 at low potential.The morphological characterizations of the hybrid film prepared with different electrodeposition time,different electrodeposition potential,different mass ratio of chitosan and HAuCl4 have been investigated.An amperometric immunosensor for determination of human serum chorionic gonadotrophin （hCG） was constructed by immobilizing hCG antibody with nano-gold and chitosan hybrid film electrochemical co-deposited on a glassy carbon electrode.The effect of incubation time on the electrochemical behavior of immunosensor was studied.The effects of other experimental conditions such as mass ratio of chitosan to HAuCl4,depositing time of hybrid film,the pH,and temperature were studied too.The current response of the immunosensor is in a linear relationship with concentration of hCG.The immunosensor offers an excellent amperometric response for hCG in a range from 0.20 to 100 mIU/mL with a detection limit of 0.1 mIU/mL.