Co-operation of Electrochemistry and Chemometrics to Develop a Novel Electrochemical Aptasensor Based on Generation of First- and Second-Order Data for Selective and Sensitive Determination of the Prostate Specific Antigen Biomarker

In this work, a novel electrochemical aptasensor was fabricated based on modification of glassy carbon electrode with prostate specific antigen (PSA) binding DNA aptamer (5'-HS-(CH2)(6)-TTTTTA ATT AAA GCT CGC CAT CAA ATA GCTTT-3')/gold nanoparticles/electrochemically reduced fullerene-C-60/multi-walled carbon nanotubesionic liquid-graphene (APT/Au NPs/C-60/MWCNTs-IL-Gr/GCE). By incubation of the aptasensor with the PSA and binding of the PSAs with the APTs, steric hindrance at the aptasensor was increased therefore, the voltammetric response of the aptasensor immersed in the electrochemical probe solution was decreased. Three electrochemical methods including differential pulse voltammetry (DPV), square wave voltammetry (SWV) and amperometry were used to assist the aptasensor for determination of the PSA, and the best one was chosen for the analysis of real matrices. Second-order DPV data, first-order SWV and amperometric data were generated and used to assist the aptasensor. Second-order DPV data were modeled by PARAFAC2 and MCR-ALS while SWV and amperometric data were modeled based on classical univariate calibration methods to build the calibration models. After evaluation of the performances of different calibration models in the analysis of synthetic samples, the second-order calibration based on DPV data modeled by MCR-ALS was chosen as the best calibration model to assist the aptasensor for the analysis of serum samples as real matrices. Fortunately, the aptasensor assisted by MCR-ALS had a very good performance for the determination of the PSA in serum samples which was comparable with a reference method.