Nitrocellulose/acrylic resin coated screen-printed carbon electrode to construct a capacitive immunosensor for anti-BSA.

The capacitive immunosensor, known for its label-free simplicity, has great potential for point-of-care diagnostics. However, the interaction between insulation and recognition layers on the sensing electrode greatly affects its performance. This study introduces a pioneering dual-layer strategy, implementing a novel combination of acrylic resin (AR) and nitrocellulose (NC) coatings on screen-printed carbon electrodes (SPCEs). This innovative approach not only enhances the dielectric properties of the capacitive sensor but also streamlines the immobilization of recognizing elements. Particularly noteworthy is the superior reliability and insulation offered by the AR coating, surpassing the limitations of traditional self-assembled monolayer (SAM) modifications. This dual-layer methodology establishes a robust foundation for constructing capacitive sensors optimized specifically for liquid medium-based biosensing applications. The NC coating in this study represents a breakthrough in effectively immobilizing BSA, unraveling the capacitive response intricately linked to the quantity of adsorbed recognizing elements. The results underscore the prowess of the proposed immunosensor, showcasing a meticulously defined linear calibration curve for anti-BSA (ranging from 0 to 25 μg/ml). Additionally, specific interactions with anti-HAS and anti-TNF-α further validate the versatility and efficacy of the developed immunosensor. This work presents a streamlined and highly efficient protocol for developing label-free immunosensors for antibody determination and introduces a paradigm shift by utilizing readily available electrodes and sensing systems. The findings are poised to catalyze a significant acceleration in the advancement of biosensor technology, opening new avenues for innovative applications in point-of-care diagnostics.