Bioinspired porous and electroactive reduced graphene oxide hydrogel based biosensing platform for efficient detection of Tumor Necrosis Factor-α

Abstract

Oral cancer is one of the leading cancer types, which is frequently diagnosed at an advanced stage, giving patients a poor prognosis and fewer therapeutic choices. To address this gap, exploiting biosensors utilizing anti-biofouling hydrogels for early-stage oral cancer detection in non-invasive body fluids is gaining utter importance. Herein, we have demonstrated the fabrication of an innovative electrochemical immunosensor for the rapid, label-free, non-invasive, and affordable detection of Tumor Necrosis Factor-α (TNF-α), a biomarker associated with oral cancer progression in artificial saliva samples. The gold screen-printed electrodes (gSPE) are modified with green synthesised porous, and electroactive reduced graphene oxide (rGO) hydrogel utilizing L-cystine (L-cys) as both in-situ reducing and surface functionalization agent, followed by covalent immobilization of anti-TNF-α and blocking of residual sites with bovine serum albumin (BSA) to fabricate the BSA/anti-TNF-α/L-cys_rGO hydrogel/gSPE immunosensing platform. The fabricated platform demonstrates excellent performance, with a low limit of detection of 1.20 pg/mL, a broad linear range from 1 to 200 pg/mL, and a high sensitivity of 2.10 µA pg-1 mL cm-2 carried out with differential pulse voltammetry technique. Moreover, it exhibits specificity towards TNF-α, even in the presence of potential interferents and other cancer biomarkers. Besides, the biosensor showed good reproducibility as well as repeatability with a relative standard deviation (%RSD) of 5.11% and 1.85%, respectively. Thus, integrating L-cys_rGO hydrogel in the immunosensor design offers enhanced performance, paving the way for its application in early-stage oral cancer diagnosis.