Simultaneous electrochemical immunosensor based on water-soluble polythiophene derivative and functionalized magnetic material

• A special water-soluble conducting polymer was been first used in the immunosensor.
• PDPMT-Cl has good electrical conductivity and solubility.
• Functionalized magnetic material makes the simultaneous detection of two analytes possible.

A novel, sensitive electrochemical immunosensor for simultaneous determination of squamous cell carcinoma associated antigen (SCC-Ag) and carcinoembryonic antigen (CEA) for the combined diagnosis of cervical cancer was designed. The amplification strategy for electrochemical immunoassay was based on poly[3-(1,1′-dimethyl-4-piperidine-methylene) thiophene-2,5-diylchloride] (PDPMT-Cl) and functionalized mesoporous ferroferric oxide nanoparticles (Fe3O4 NPs). PDPMT-Cl dispersed in chitosan solution with enhanced electrical conductivity and solubility was used as matrices to immobilize the first antibodies. Different redox probes (thionine (Th) and ferrocenecarboxylic acid (Fca)) functionalized Fe3O4 NPs incubated with two kinds of secondary antibodies to fabricate the labels. Using an electrochemical analysis technique, two well-separated peaks were generated by Th and Fca, making the simultaneous detection of two analytes on the electrode possible. Under optimized conditions, this method showed wide linear ranges of three orders of magnitude with the detection limits of 4 pg mL−1 and 5 pg mL−1, respectively. The disposable immunosensor possessed excellent clinical value in cervical cancer screening as well as convenient point-of-care diagnostics.

In this study, a novel, sensitive electrochemical immunosensor for simultaneous determination of squamous cell carcinoma associated antigen (SCC-Ag) and carcinoembryonic antigen (CEA) based on poly[3-(1,1′-dimethyl-4-piperidine-methylene) thiophene-2,5-diylchloride] (PDPMT-Cl) and functionalized mesoporous ferroferric oxide nanoparticles (Fe3O4 NPs) for the combined diagnosis of cervical cancer was designed.Figure optionsDownload as PowerPoint slide