Ultrasensitive potentiometric immunosensor based on SA and OCA techniques for immobilization of HBsAb with colloidal Au and polyvinyl butyral as matrixes.
A novel potentiometric immunosensor for detection of hepatitis B surface antigen (HBsAg) has been developed by means of self-assembly (SA) and opposite-charged adsorption (OCA) techniques to immobilize hepatitis B surface antibody (HBsAb) on a platinum electrode. A cleaned platinum electrode was first pretreated in the presence of 10% HNO3 and 2.5% K2CrO4 solution and held at -1.5 V (vs SCE) for 1 min to make it negatively charged and then immersed in a mixing solution containing hepatitis B surface antibody, colloidal gold (Au), and polyvinyl butyral (PVB). Finally, HBsAb was successfully immobilized onto the surface of the negatively charged platinum electrode modified nanosized gold and PVB sol-gel matrixes. The modified procedure was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The immobilized hepatitis B surface antibody exhibited direct electrochemical behavior toward hepatitis B surface antigen (HBsAg). The performance and factors influencing the performance of the resulting immunosensor were studied in detail. More than 95.7% of the results of the human serum samples obtained by this method were in agreement with those obtained by enzyme-linked immunosorbent assays (ELISAs). The resulting immunosensor exhibited fast potentiometric response (<3 min) to HBsAg. The detection limit of the immunosensor was 2.3 ng.mL(-1), and the linear range was from 8 to 1280 ng.mL(-1). Moreover, the studied immunosensor exhibited high sensitivity, good reproducibility, and long-term stability (>6 months).
Yuan
Ruo
R
Chong Qing Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, China. yuanruo@swnu.edu.cn
Tang
Dianping
D
Chai
Yaqin
Y
Zhong
Xia
X
Liu
Yan
Y
Dai
Jianyuan
J
D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003102:Colloids / Q000737:chemistry*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006510:Hepatitis B Antibodies / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010984:Platinum / Q000737:chemistry; D011145:Polyvinyls / Q000737:chemistry*; D011199:Potentiometry / Q000295:instrumentation / Q000379:methods; D012680:Sensitivity and Specificity; D044967:Serum / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
D003102:Colloids; D006510:Hepatitis B Antibodies; D011145:Polyvinyls; D010984:Platinum; D006046:Gold; C027464:polyvinylbutyral