# Determination of p53 biomarker with a smart electrochemical biosensor based on brush polymer-functionalized disposable electrode

## TL;DR

A smart electrochemical biosensor was developed to detect the p53 protein in human serum, offering high sensitivity and potential for early cancer detection.

## Contribution

A novel label-free impedimetric biosensor using a brush polymer-functionalized electrode for p53 detection was developed.

## Key findings

- The biosensor detected p53 concentrations as low as 15.9 fg/mL with a linear range of 0.05 to 15 pg/mL.
- The biosensor showed high reproducibility, good storage stability, and successful regeneration through acidic treatment.
- It successfully detected p53 in human serum samples with recycling rates between 98.41% and 109.32%.

## Abstract

A label-less impedimetric biosensor modified with poly(thiophene)-graft-poly(glycidyl methacrylate) polymer (PThi-g-PGM) was manufactured for p53 protein quantification in human serum samples. In this study, PThi-g-PGM polymer was synthesized, and this polymer matrix was coated using the spin-coating technique on the single-use indium tin oxide (ITO) substrate for anti-p53 antibody immobilization. The anti-p53 antibodies with high affinity for p53 proteins were covalently attached onto the PThi-g-PGM-coated electrode surface. In addition, the affinity of anti-p53 for the p53 protein was monitored at a constant frequency. Under optimized conditions, the impedimetric changes were linearly related to the p53 concentrations, ranging from 0.05 to 15 pg/mL with a low detection limit of 15.9 fg/mL. This biosensor had desirable storage stability, acceptable repeatability, and high reproducibility. Moreover, this impedimetric biosensor could be regenerated through an acidic treatment procedure. Additionally, the suggested biosensor successfully detected the p53 antigen in human serum samples, and good recycling rates (98.41%–109.32%) were found. In summary, the proposed immunosensor may be a powerful tool for the analysis of the p53 protein for early detection of cancer biomarkers.