| Abstract: | A human chorionic gonadotrophin (hCG) doped gold nanoparticles–chitosan membrane was prepared for forming an immunoconjugate of horseradish peroxidase labeled hCG antibody and hCG on glassy carbon electrode. The nanoparticles provided a congenial environment of the adsorbed proteins. Thus, the immobilized HRP‐labeled immunoconjugate showed good enzymatic activity for the oxidation of o‐phenylenediamine by H2O2. With a competitive mechanism, an amperometric method for immunoassay of hCG up to 30 mIU mL?1 with a relatively low detection limit of 0.26 mIU mL?1 at 3σ was developed. The hCG immunosensor showed good precision, high sensitivity, acceptable stability and reproducibility. |
