Thermodynamic and kinetic analysis of the interaction between hepatitis B surface antibody and antigen on a gold electrode modified with cysteamine and colloidal gold via electrochemistry.
Hepatitis B surface antibody (HBsAb) was immobilized to the surface of a gold electrode modified with cysteamine and colloidal gold as matrices to detect hepatitis B surface antigen (HBsAg). Differential pulse voltammetry (DPV) method was used for the investigation of the specific interaction between the immobilized HBsAb and HBsAg in solution, which was followed as a change of peak current in DPV with time. With the modified gold electrode, the differences in affinity of HBsAb with HBsAg at the temperatures of 37 and 40 degrees C were easily distinguished and the kinetic rate constants (k(ass) and k(diss)) and kinetic affinity constant K were determined from the curves of current versus time. In addition, the thermodynamic constants, DeltaG, DeltaH and DeltaS, of the interaction at 37 degrees C were calculated, which were -56.65, -64.54 and -25.45 kJ mol(-1), respectively.
He
Yan Bin
YB
School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Luo
Hong Qun
HQ
Li
Nian Bing
NB
D000937:Antigen-Antibody Reactions; D003543:Cysteamine / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D017979:Gold Colloid / Q000737:chemistry*; D006510:Hepatitis B Antibodies / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006801:Humans; D007700:Kinetics; D013816:Thermodynamics
D017979:Gold Colloid; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D003543:Cysteamine