A novel electrochemical sensor based on citrate-capped platinum nanoparticles (Pt-Citrate) modified nanostructured electrodes is presented for the sensitive and selective detection of cadmium (Cd). A susceptible method, Square wave voltammetry (SWV) was employed as the analytical technique. The proposed sensing scheme exhibited exceptional performance with a sensitivity threshold of 0.041 µM, a high sensitivity of 30.04 µA µM−1, within a linear response range of 0.1–0.5 µM. The sensor demonstrated superior selectivity towards Cd in the presence of common interfering ions (F−, Fe2+, NO2− & Cu2+). Practical applicability was validated through accurate Cd determination sing tapwater. The achieved sensitivity threshold significantly surpasses permissible Cd levels in drinking water, underscoring the sensor's potential for effective real-time monitoring of Cd contamination in environmental matrices.