Nanoengineered hybrid hydrogel-based 3D nanocomposite as an antifouling coating interface for enhanced electrochemical aptasensing of estradiol.

Electrochemical biosensing has emerged as a promising method for the point-of-care detection of various biomarkers. However, its clinical application faces significant challenges due to biofouling when exposed to clinical samples. This study presents a novel nanocomposite coating aimed at addressing biofouling in electrochemical biosensors by developing an Electrochemical Estradiol Aptasensor (EAS). We developed a nanoengineered, hybrid hydrogel-based 3D antifouling nanocomposite interface (ANcI) by crosslinking carboxymethyl chitosan with sodium carboxymethyl cellulose and incorporating highly conductive Ti₃C₂T_x MXene nanostructures. The Aptasensor was constructed on a screen-printed carbon electrode by applying the ANcI as an antifouling layer, followed by the deposition of a gold nanoparticle support layer modified with estradiol-specific aptamers, which serves as the biorecognition element. We evaluated the antifouling capabilities by comparing the performance of the Aptasensor with and without the ANcI when exposed to human serum and bovine serum albumin. This innovative nanocomposite coating offers excellent antifouling properties along with a highly porous structure and electrical conductivity, which are essential for maintaining sensor performance in complex clinical samples. By addressing the limitations of existing antifouling materials, this approach paves the way for the commercialization of electrochemical biosensors with enhanced accuracy and sensitivity. The sensors demonstrate a clinically relevant concentration range of 0.1 pg/mL to 1000 pg/mL, with a limit of detection of 0.127 pg/mL. These findings highlight the potential of this innovative approach to improve electrochemical biosensing across various applications and significantly impact biomarker detection in clinical samples.