An amperometric immunosensor based on a conducting immunocomposite electrode for the determination of Schistosoma japonicum antigen

Anal Sci. 2002 Feb;18(2):155-9. doi: 10.2116/analsci.18.155.


A renewable amperometric immunosensor based on a graphite-paraffin-Schistosoma japonicum antibody (SjAb) biocomposite electrode has been prepared for the detection of Schistosoma japonicum antigen (SjAg). Competitive ELISA was employed involving HRP-SjAg as a tracer and 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate. The product of an enzyme catalytic reaction was detected at +0.1 V (vs. Ag/AgCl reference electrode) for measuring the amount of HRP-labeled SjAg binding to the electrode surface. The assay conditions were optimized, including the amount of SjAb loading in the electrode and HRP-SjAg in the incubation solution, the pH of the measuring solution and the incubation time. The measuring range was 0.5-30 microg/ml under the optimum conditions. Rabbit serum samples of different infection degree were measured, which demonstrated that the immunosensor meets the demands of clinical analysis. It exhibits some advantages, such as simplicity of fabrication, rapidity of measurement, and satisfactory sensitivity and reproducibility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Helminth / analysis*
  • Benzidines / chemistry
  • Cattle
  • Chromogenic Compounds / chemistry
  • Electrochemistry
  • Electrodes
  • Enzyme-Linked Immunosorbent Assay
  • Graphite
  • Humans
  • Hydrogen-Ion Concentration
  • Immunochemistry
  • Indicators and Reagents
  • Paraffin
  • Rabbits
  • Schistosoma japonicum / immunology*
  • Serum Albumin, Bovine


  • Antigens, Helminth
  • Benzidines
  • Chromogenic Compounds
  • Indicators and Reagents
  • Serum Albumin, Bovine
  • 3,3',5,5'-tetramethylbenzidine
  • Graphite
  • Paraffin