Electrochemical detection of hepatitis B surface antigen using colloidal gold nanoparticles modified by a sol-gel network interface.
BACKGROUND
A novel potentiometric immunosensor for the detection of hepatitis B surface antigen has been developed by self-assembling gold nanoparticles to a thiol-containing sol-gel network.


METHODS
A cleaned gold electrode was first immersed in a hydrolyzed (3-mercaptopropyl) trimethoxysilane sol-gel solution to assemble a three-dimensional silica gel, and then gold nanoparticles were absorbed onto the thiol groups of the sol-gel network. Finally, hepatitis B surface antibody was assembled onto the surface of the gold nanoparticles. The self-assembling procedure was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Detection is based on the change in potentiometric response before and after the antigen-antibody reaction.


RESULTS
Tests relating to the detection of hepatitis B surface antigen demonstrate that the potentiometric immunosensor exhibited a rapid potentiometric response (<4 min), with high sensitivity, good reproducibility, and long-term stability. The linear range was from 4 to 960 ng.mL(-1) with a detection limit of 1.9 ng.mL(-1) (S/N = 3) and the lifetime was 1 month.


CONCLUSIONS
Analytical results of several specimens using the developed technique showed satisfactory agreement with those from an ELISA method. This method shows promise for detecting HBsAg in clinical specimens.
Tang
Dianping
D
Key Laboratory of Analytical Chemistry, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P.R. China.
Yuan
Ruo
R
Chai
Yaqin
Y
Zhong
Xia
X
Liu
Yan
Y
Dai
Jianyuan
J
D002138:Calibration; D017097:Electric Impedance; D004563:Electrochemistry; D004566:Electrodes; D005782:Gels / Q000737:chemistry; D017979:Gold Colloid / Q000737:chemistry*; D006514:Hepatitis B Surface Antigens / Q000032:analysis* / Q000737:chemistry; D007118:Immunoassay; D049329:Nanostructures / Q000737:chemistry*; D011199:Potentiometry; D015203:Reproducibility of Results
D005782:Gels; D017979:Gold Colloid; D006514:Hepatitis B Surface Antigens