Ultrasonic Synthesis of Nanotubular Hausmannite with Peapod-Like Morphology for Sensitive and Selective Electrochemical Nicotine Detection

A novel nanotubular hausmannite (NT-HSM) was synthesized using a readily available ultrasonic water bath and thoroughly characterized. Transmission electron microscopy (TEM) confirmed the formation of nanotubes with an average diameter of ~ 10 nm, featuring distinctive pea-pod-like structures both within and on the outer walls, which served as nucleation sites for uniform nanotube growth. The electrochemical properties of NT-HSM were evaluated by modifying a glassy carbon electrode (GCE) and employing it for the sensitive detection of nicotine. Electrochemical quantification was performed using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometry in 0.05 M NaClO₄ (pH 7). DPV and amperometric measurements demonstrated a linear relationship between peak current and nicotine concentration in the range of 1–130 µM, with a detection limit of 0.9 µM. The impact of common interfering species such as ascorbic acid (AA) and uric acid (UA) was assessed, revealing no significant influence on the oxidation response of nicotine, thereby confirming the high selectivity of the NT-HSM modified electrode. The electro-oxidation of nicotine was attributed to an intermediate electron transfer mechanism facilitated by the Mn³⁺/Mn²⁺ redox couple. Furthermore, the NT-HSM based sensor was successfully applied to the determination of nicotine in commercial cigarette sample, exhibiting a well-defined and reproducible redox response. These findings highlight the potential of NT-HSM as an efficient electrode modifier for selective and sensitive nicotine detection.

Graphical Abstract