Preparation of hexagonal boron nitride doped graphene film modified sensor for selective electrochemical detection of nicotine in tobacco sample.

The selective detection of nicotine is necessary in biological and biomedical samples to screen the patients who has the neurodegenerative diseases due to tobacco addiction. For this purpose, we have synthesized a hybrid binary composite made of 2D hexagonal boron nitride nanosheets (BN) doped graphene film via a scalable top-down technique for the electrochemical detection of nicotine. Transmission electron microscopy (TEM) images showed that layered graphene sheets bounded with BN nanosheets. Moreover, Fourier-transform infrared (FT-IR), UV-visible (UV-vis), and X-ray photoelectron spectroscopies (XPS) confirmed successful integration of BN within graphene. In addition, the electrical conductivity of the nanocomposite was tested using electrochemical impedance spectroscopy (EIS), which showed high electrical conductivity of BN/graphene coated electrode with low charge transfer resistance. To develop a selective nicotine sensor, glassy carbon electrode (GCE) surface was coated with BN/graphene hybrid film and tested its electro-catalytic activity against nicotine. It was found that BN/graphene/GCE based sensor exhibited excellent electro-catalytic activity for nicotine oxidation at lower potential of +0.97 V in phosphate buffer solution (PBS, pH 7.0) and the linear response was observed from 1 to 1000 μM. The limit of detection (LOD) was estimated as 0.42 μM. The common interferent compounds such as uric acid (UA), paracetamol (PA), glucose (Glu), melamine (Mel), cysteine (Cys) and dopamine (DA) did not interfere on the sensor selectivity. Furthermore, BN/graphene/GCE exhibited high stability and reproducibility. Finally, BN/graphene/GCE-based sensor was successfully applied to detect nicotine in a tobacco sample with high recovery.