Silver anchored g-C3N4/CNT nanocomposites modified glassy carbon electrode for the detection of α-lipoic acid in pharmaceutical products

AgNPs anchored g-C3N4/CNT nanocomposites have been exploited for the electrochemical sensitive determination of α-lipoic acid (α-LA) in pharmaceutical tablets. The developed g-C3N4/CNT@AgNPs were synthesized by the biogenic reduction method using lemon extract as a reducing agent and characterized by using various analytical techniques like FE-SEM, EDAX, FT-IR, XRD, and UV–visible spectroscopy. The g-C3N4/CNT@AgNPs nanocomposites with modified glassy carbon electrodes (GCE) were fabricated and their electrochemical analysis was performed by CV and EIS techniques. Modified electrodes (g-C3N4/CNT@AgNPs/GCE) exhibited superior electrocatalytic behaviour towards the oxidation of α-LA due to the synergistic effect between AgNPs and g-C3N4/CNT composites. Under optimized experimental conditions, the highest peak current response was perceived for the oxidation α-LA with a peak potential of +0.916 V (vs. Ag/AgCl). Linear response ranges for the DPV determination of α-LA are 1.3 × 10−6–24 × 10−6 M (R2 = 0.9983) with a detection limit of (S/N = 3) of 0.038 × 10−6 M and the sensitivity is 10.5866 µA µM−1 cm−2. Fabricated electrode reveals better outstanding features like good repeatability and reproducibility, selectivity and sensitivity, long-term storage steadiness, strong anti-interference ability, etc. The proposed sensor exhibits success in the determination of α-LA in pharmaceutical samples with better recovery ranges.