V2C MXene nanosheets and Au particles-decorated boron-doped diamond electrodes for non-enzymatic glucose sensing

Non-enzymatic glucose sensors are attractive alternatives to enzyme-based systems due to their improved chemical stability, but their analytical performance depends heavily on electrode surface design. In this work, a hybrid electrode based on V 2 C MXene and gold (Au) particles supported on boron-doped diamond (BDD) was fabricated and evaluated for electrochemical glucose detection. V 2 C MXene was obtained by selective etching of V 2 AlC, producing a layered and conductive coating on the BDD surface. Subsequent deposition of Au particles introduced additional catalytic sites for glucose oxidation. Structural and surface characterization confirmed the formation of V 2 C MXene, preservation of carbide bonding, and the presence of metallic Au. Electrochemical measurements in phosphate-buffered saline showed that the BDD-V 2 C-Au electrode exhibited a sensitivity of 24.14 μA ppm −1 cm −2 , a detection limit of 0.15 ppm, and a linear response over the concentration range from 0.18 to 125 ppm. Compared with the BDD-V 2 C electrode, Au modification led to a significant enhancement in current response. The electrode also showed good repeatability and short-term stability in different supporting electrolytes. When compared with representative non-enzymatic glucose sensors reported in the literature, the BDD-V 2 C-Au provided a well-defined balance between sensitivity, detection limit, and operational stability. These results highlight the potential of MXene-noble metal interfaces on diamond substrates for stable, non-enzymatic glucose sensing under controlled conditions.