Construction of Mo-Doped CuO Incorporated on Carbon Black Modified Disposable Sensor for the Voltammetric Detection of Metol in Environmental Samples

In this study, a molybdenum-doped copper oxide (Mo–CuO) composite was synthesized via a hydrothermal method and combined with carbon black (CB) to form Mo–CuO@CB. This composite was used to modify a screen-printed carbon electrode (SPCE) for the detection of Metol (MT), an industrial pollutant harmful to both human health and the environment. Structural and surface characterization was performed using high-resolution transmission electron microscopy, field-effect scanning electron microscopy, energy-dispersive spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Electrochemical techniques, including differential pulse voltammetry and cyclic voltammetry, were used to assess the sensor’s performance. The Mo–CuO@CB@SPCE sensor exhibited a low detection limit of 2.7 nM, and limit of quantification is 82 nM, a broad linear range (5.0 × 10 −9 –170 mol L −1 ), and high sensitivity (4.148 μA μM −1 cm −2 ), benefiting from the catalytic activity of Mo–CuO and the large surface area of CB. With recovery rates ranging from 96% to 100.6% in pond, river, and tap water, the sensor effectively detects MT in environmental samples, ensuring reliable monitoring of this persistent pollutant.