Ultrasensitive Electrochemical Detection of EpCAM Antigen Based on Anti-EpCAM Conjugated With Highly Flexible Ag@Ti3C2Tx Modified Conducting Paper Platform

In this work, a highly bendable Whatman paper-based immunosensor has been proposed for highly sensitive and real-time detection of EpCAM antigen. A novel Ag@Ti3C2Tx hybrid material is used with aqueous poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) [PEDOT:PSS] solution to enhance various electrochemical parameters, namely, conductivity, hydrophilicity, stability, and so forth. The conducting paper has been fabricated by simple dip-coating method followed by doping with dimethyl sulfoxide (DMSO), an organic solvent. The DMSO treatment results in the sharp increase in electrical conductivity of Ag@Ti3C2Tx/CP from 10.9 x 10(-3) to 763.5 x 10(-3) S/cm (around 70 times). Further, the bendability of the fabricated conducting paper is verified by paper folding study at different angles. The developed immunosensor, anti-EpCAM/Ag@Ti3C2Tx/CP, is found to be highly sensitive (44.12 mu A<middle dot>fg(-1)<middle dot>mL) to detect EpCAM antigen with ultrabroad linear range (1 fg/mL-10,000 pg/mL). Ultimately, the manufactured immunosensor is used to assess the EpCAM in spiked serum samples, and the results demonstrate a strong correlation with the standard buffer samples.