In Situ Ag-Seeded Lamellar Ti3C2 Nanosheets: An Electroactive Interface for Noninvasive Diagnosis of Oral Carcinoma via Salivary TNF-α Sensing

In the fast-paced quest for early cancer detection, noninvasive screening techniques have emerged as game-changers, offering simple and accessible avenues for precession diagnostics. In line with this, our study highlights the potential of silver nanoparticle-decorated titanium carbide MXene nanosheets (Ti3C2_AgNPs) as an electroactive interface for the noninvasive diagnosis of oral carcinoma based on the prevalence of the salivary biomarker, tumor necrosis factor-α (TNF-α). An in situ reduction was utilized to synthesize the Ti3C2_AgNPs nanohybrid, wherein Ti3C2 acts as the reducing agent, and the resulting nanohybrid was subjected to various characterization techniques to examine the optical, structural, and morphological attributes. The results revealed that spherical AgNPs formed on the surface of Ti3C2 MXene nanosheets by virtue of the low-valent Ti species present in Ti3C2, which facilitated the reduction of AgNO3 to AgNPs. Furthermore, the electrochemical characterization of the nanohybrid-modified screen-printed electrode (Ti3C2_AgNPs/SPE) indicated enhanced heterogeneous electron transfer kinetics. With these encouraging results, the Ti3C2_AgNPs nanohybrid was employed as an immobilization matrix for TNF-α antibodies and applied for electrochemical sensing. Analytical studies of the fabricated immunosensor, conducted by differential pulse voltammetry (DPV), exhibited a broader linear range (1 to 180 pg mL–1), a low limit of detection (0.97 pg mL–1), and high sensitivity (1.214 μA mL pg–1 cm–2) and specificity, even in artificial saliva, indicating its reliability for oral carcinoma diagnosis. Therefore, the Ti3C2_AgNP nanohybrid seems a promising candidate for the effective sensing of TNF-α and could also be explored for other biomarkers.