Engineering a multifunctional hybrid polymer-hydrogel nanocomposite for high-sensitivity, anti-fouling electrochemical immunodetection in early cancer diagnosis

Abstract

This work introduces a novel dual-component electrode modifier comprising gold nanoparticles (AuNPs) and a hydrated form of the poly(3,4-ethylenedioxythiophene) (hPEDOT) conducting polymer to enhance biomolecule immobilization and signal amplification in electrochemical immunosensing. The thiophene–AuNP interaction promotes electropolymerization, forming a citrate-doped matrix with carboxyl groups that enable covalent, oriented antibody anchoring. Moreover, the hydration of the polymeric scaffold enhances the biocompatibility and anti-fouling properties of the sensing interface. This multifunctional polymer–hydrogel nanocomposite was used to develop a disposable sandwich-type electrochemical immunoplatform for the determination of human endostatin (HE), a biomarker of colorectal cancer (CRC). The immunoplatform achieved a detection limit of 0.04 ng mL⁻1 and distinguished not only healthy individuals from early-stage CRC patients but also from those with premalignant colorectal lesions. These findings underscore the potential of this new multifunctional hybrid nanocomposite to improve the performance of electrochemical immunosensing, which is crucial for timely cancer diagnosis and intervention.