Synergistic interfacial coupling in VS₂-MWCNT nanocomposite enhancing electrochemical response towards C3 protein detection.

Glaucoma leads to permanent loss of retinal ganglion cells and progressive optic nerve damage, making early diagnosis essential for preventing vision impairment. Identifying reliable, non-invasive molecular biomarkers can significantly improve early intervention and patient outcomes. In this work, an electrochemical biosensor is reported engineered from a vanadium disulfide-multiwalled carbon nanotube (VS₂-MWCNT) nanocomposite for detecting complement component C3, a biomarker associated with glaucoma progression. The VS₂-MWCNT nanofibers were produced by electrospinning a mixture of hydrothermally synthesized VS₂ and multiwalled carbon nanotubes, followed by comprehensive characterization using Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). When deposited onto glassy carbon electrodes (GCEs), the hybrid nanofibers displayed improved surface adhesion, electrochemical performance and stability in comparison with pristine VS₂. The resulting C3 biosensor achieved ultralow detection limits of 3.652 fg/mL (CV) and 1.1052 fg/mL (EIS) with a linear detection range for the logarithm of 100 fg/mL to 1 µg/mL C3 concentrations. These findings highlight a robust and highly sensitive sensing platform with strong promise for early-stage glaucoma detection and potential clinical application.