We provide a simple, robust, and novel method based on a stable dispersion of α-alumina (Al2O3) nanoparticles to modified glassy carbon electrode (GCE) for the quantitative detection of the tinidazole (TIN) drug, a derivative of the nitroimidazole moiety. Because of the adverse effects due to the consumption of large quantities, we need an analytical tool for quantitative detection. A well-defined reduction peak potential for TIN was observed at − 0.65 V vs. Ag/AgCl with enhanced catalytic peak at Chit@alumina modified GCE at neutral pH (0.1 M PBS). Under the experimental conditions, the fabricated electrode shows a broad linear response to concentrations of TIN in the ranges of 6.0 × 10−9 M to 36 × 10−6 M with correlation coefficient of 0.9974. The lowest detection limit was identified as 16 nM, and the current sensitivity was measured to be 12.16 μA∙ nM−1∙cm−2. Furthermore, the synthesized voltammetic sensor has adequate recovery ranges, remarkable anti-interference performance against biomarkers and other electroactive molecules, and also exhibits good storage stability and repeatability. The developed sensor's application studies were successfully used to detect TIN in biological specimens and drug tabulations.