Immunoelectrochemical Detection of Prostate-Specific Antigen on PEDOT/Cerium Phosphate Nanotubes Modified ITO Electrode

Abstract

Herein, a label-free electrochemical immunosensor was developed to detect prostate-specific antigen (PSA), a biomarker for prostate cancer. The immunosensor was fabricated by modifying one-dimensional nanomaterial CePO4 nanotubes, electrodepositing poly-3,4-ethylenedioxythiophene layer, anchoring monoclonal antibodies to PSA, and blocking with bovine serum albumin on the surface of the indium tin oxide sheet. The morphologies and electrochemical performance of the electrochemical sensor were characterized by Fourier transform infrared spectrophotometry, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. For PSA, it exhibits a wide dynamic range from 0.1 ng ml−1 to 100 ng ml−1 and a detection limit of 0.012 ng ml−1 (at a signal-to-noise ratio of 3) with differential pulse voltammetry. Average recoveries from rat serum (a simulated human serum) are between 97.00%–103.17% with relative standard derivations less than 4.25% (n = 3) at three spiked levels. Moreover, it shows high reproducibility, well selectivity, and good stability. The immunosensor provides an effective tool in the clinical diagnosis of prostate cancer.