Development of an electrochemical immunosensor based on gold nanoparticles incorporated chitosan biopolymer nanocomposite film for the detection of prostate cancer using PSA as biomarker

Enzyme Microb Technol. 2018 May;112:43-51. doi: 10.1016/j.enzmictec.2017.10.009. Epub 2017 Oct 24.

Abstract

In this study, we have developed an electrochemical immunosensor for the detection of prostate-specific antigen (PSA) based on gold nanoparticles (AuNPs) and a chitosan (CHI) nanocomposite film coated on a screen printed electrode (SPE). The modified SPE was characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The immunosensor was fabricated by sequential immobilization of anti-PSA primary antibody, PSA antigen and HRP-tagged secondary antibody on the surface of AuNPs/CHI/SPE. When this immunosensor was placed in 2.5mM H2O2, as HRP substrate, and 1mM methylene blue (MB), as redox mediator, greatly amplified immunosensing signals were observed. Immunosensing signals for the reduction of H2O2 were monitored in phosphate buffer (pH 7.0) by CV and square wave voltammetry (SWV). Under optimized conditions steady state current increased linearly with PSA concentration over the range 1-18ng/ml with a detection limit of 0.001ng/ml. The fabricated immunosensor demonstrated excellent sensitivity, stability and reproducibility and therefore was successfully applied to analyse PSA in biological samples. Finally, the results indicate that the proposed immunosensor has potential in clinical screening of cancer biomarkers.

Keywords: Chitosan; Cyclic voltammetry etc.; Electrochemical immunosensor; Gold nanoparticles; Methylene blue; Prostate-specific antigen.

Publication types

  • Evaluation Study

MeSH terms

  • Biosensing Techniques / instrumentation*
  • Chitosan / chemistry
  • Electrochemical Techniques / instrumentation
  • Equipment Design
  • Gold / chemistry
  • Humans
  • Male
  • Metal Nanoparticles / chemistry
  • Nanocomposites / chemistry
  • Prostate-Specific Antigen / analysis*
  • Prostatic Neoplasms / diagnosis*
  • Prostatic Neoplasms / immunology*

Substances

  • Gold
  • Chitosan
  • Prostate-Specific Antigen