Fabrication of a novel tantalum boride/vanadium carbide modified screen-printed carbon electrode for voltammetric determination of pimonidazole in bio-fluids

For the first time, a tumour hypoxia marker detection has been developed using two-dimensional layered composite modified electrodes in biological and environmental samples. The concept of TaB 2 and V 4 C 3 -based MXene composite materials is not reported hitherto using ball-milling and thermal methods and it remains the potentiality of the present work. The successful formation is confirmed through various characterisation techniques like X-ray crystallography, scanning electron microscopy photoelectron, and impedance spectroscopy. A reliable and repeatable electrochemical sensor based on TaB 2 @V 4 C 3 /SPCE was developed for quick and extremely sensitive detection of pimonidazole by various electroanalytical methods. It has been shown that the modified electrode intensifies the reduction peak current and causes a decrease in the potential for reduction, in comparison with the bare electrode. The proposed sensor for pimonidazole reduction has strong electrocatalytic activity and high sensitivity, as demonstrated by the cyclic voltammetry approach. Under the optimal experimental circumstances, differential pulse voltammetry techniques were utilised for generating the wide linear range (0.02 to 928.51 µM) with a detection limit of 0.0072 µM. The resultant data demonstrates that TaB 2 @V 4 C 3 /SPCE nano-sensor exhibits excellent stability, reliability, and repeatability in the determination of pimonidazole. Additionally, the suggested sensor was successfully used to determine the presence of pimonidazole in several real samples, such as human blood serum, urine, water, and drugs. Graphical Abstract