Cost-Effective Au-TiO2 Electrochemical Sensor for Precise Nicotine Detection in E-Liquids and Synthetic Clinical Samples

This study focused on the development of an innovative electrochemical sensor composed of TiO₂ and Au, providing an economical and highly sensitive solution for measuring nicotine (NIC), an alkaloid found in plants of the Nicotiana genus. NIC is associated with various serious diseases, such as lung cancer and vascular disorders. With the growing popularity of electronic cigarettes, accurate methods for determining NIC levels, especially due to European Union regulations are essential [1-4]. The sensor was characterized using advanced techniques, such as electron microscopy and X-ray spectroscopy, and demonstrated an optimized response at pH 7.0 in voltammetric studies. Square Wave Voltammetry (SWV) revealed two linear ranges from 2.0 to 108.9 and 159.3 to 900.8 µmol L^-1, with detection and quantification limits of 0.15 and 0.50 µmol L^-1, respectively. The method exhibited high precision and selectivity for NIC, even in the presence of urea and dopamine, highlighting its effectiveness. Furthermore, the sensor proved practical by allowing direct analysis of e-liquids without the need for prior sample preparation, increasing its applicability in real-world scenarios. To corroborate the sensor's accuracy and performance, a validation study was conducted using molecular absorption spectroscopy, confirming the method's reliability and the precision in quantifying NIC in complex samples.