High-Performance and novel photoactive Hetrostructured Field effect transistor for non-enzymatic glucose sensing

Field Effect Transistor (FET) is emerging as a next generation biosensor possessing the potential to adapt to diverse nanostructures while providing a stable and economically practical platform for achieving high sensitivity and selectivity for the analyte detection. Herein, the study demonstrates the application of an effective g-C₃N₄ and BiVO₄ based photoactive hetrostructures to develop a high performance, non-enzymatic glucose sensing field effect transistor. g-C₃N₄ nanosheets were synthesized by thermal oxidation of thiourea which were sequentially used for carbon doping to fabricate heterostructures with BiVO₄ using Carbon nanotubes (CNT) and gold (Au) nanoparticles as mediators for electrons. Four different hetrostructures BiVO₄/g-C₃N₄, g-C₃N₄/CNT/BiVO₄ g-C₃N₄/CNT/Au/BiVO₄ and C-doped g-C₃N₄/CNT/Au/BiVO₄ were fabricated for channel region to be utilized in FET. The fabricated channels were assessed for improvement g-C₃N₄/BiVO₄ in absorbance, reduction in recombination losses by decreased energy band gap and current–voltage variation. The morphological and structural analysis was confirmed by X-ray diffraction (XRD) and Transmission electron Microscopy (TEM). Current- Voltage (IV) analysis of the fabricated channels was compared for the same amount of glucose concentration. The fabricated C-doped g-C₃N₄/CNT/Au/BiVO₄ channel region based FET demonstrated long term stability after multiple uses, excellent sensitivity and enhanced photocatalytic performance. It also proved to be greatly beneficial in terms of ease of production, simplicity of usage and small size. It has the potential to recreate portable glucose biosensors for real time sensing while also providing additional benefit of other sensing biomolecules.