Protein imprinted materials designed with charged binding sites on screen-printed electrode for microseminoprotein-beta determination in biological samples

Abstract

In the past few years a large effort is being made aiming at the development of fast and reliable tests for cancer biomarkers. Protein imprinted sensors can be a fast and reliable strategy to develop tailor made sensors for a large number of relevant molecules.This work aims to produce, optimize and use in biological samples a biosensor for microseminoprotein-beta (MSMB).Caffeic acid (CAF) electropolimerization was performed in the presence of microseminoprotein-beta (MSMB) creating target protein specific cavities on the surface of a screen-printed carbon. Dopamine was introduced as charged monomer labelling the binding site and was allowed to self-organize around the protein. The subsequent electropolimerization was made by applying a constant potential of +2.0V, for 30s, on a carbon screen-printed electrode, immersed in a solution of protein and CAF prepared in phosphate buffer.The sensor with charged monomers showed a more sensitive response, with an average slope of −7.59μA/decade, linear concentration range of 0.5–100ng/mL and a detection limit of 0.12ng/mL. The corresponding non-imprinted sensor displayed an inconsistent response over the range of the calibration curve. The biosensor was successfully applied to the analysis of MSMB in serum and urine samples.