Electrochemical sensor based on tadpole-shaped Au nanostructures supported on TiO₂: Enhanced detection of nicotine in...

Nicotine (NIC) detection is vital for monitoring its presence in various environments, including tobacco products, electronic cigarettes, and clinical samples; NIC's widespread use and health implications necessitate precise and reliable detection methods as it is linked to diseases such as lung cancer and vascular disorders. In this study, we developed and characterized Au tadpole-like nanostructures immobilized onto titanium oxide (TiO₂) to provide a cost-effective and sensitive NIC detection material. The comprehensive characterization of the composite used transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), showing the robustness of the synthesis. Moreover, this material is unique due to its customized design, which combines structural features with functional capabilities, as demonstrated by the study's results. Electrochemical impedance spectroscopy (EIS) demonstrated significant enhancements in sensor performance, including improved charge transfer resistance, double-layer capacitance, and pseudocapacitance. Square wave voltammetry (SWV), performed under optimized conditions, demonstrated two linear ranges: 1.99-108.9 μmol L^-1 and 159.3-900.8 μmol L^-1, with limits of detection (LOD) and quantification (LOQ) of 0.149 and 0.497 μmol L^-1, respectively. This novel electrochemical method demonstrated high accuracy in determining NIC levels in electronic cigarettes and simulated clinical samples, with a recovery range of 99.95 %-110.1 %. Furthermore, a comparative study using molecular absorption spectrometry confirmed the sensor's performance, employing a t-test for statistical validation. Thus, the Au-TiO₂ material advances the field of electrochemical detection and provides an effective tool for NIC monitoring, with significant potential for public health guidelines.