A biosensor based on nanocomposite of g-C3N4 and polyaniline for detection of fentanyl as a doping agent in sports

Significant ethical and health concerns have been brought up recently by the illegitimate use of highly strong synthetic opioids, including fentanyl, as doping agents in sports. Therefore, the requirement for quick and accurate detection techniques to spot illicit drugs in athletes has never been more important. Our study presents a novel biosensor for the sensitive detection of fentanyl based on a nanocomposite of polyaniline (PANI) and a glassy carbon electrode modified with g-C3N4, which is the first of its kind. The g-C3N4-PANI nanocomposite's successful synthesis was confirmed by structural investigations performed using SEM, XRD, and FT-IR. Studies on the electrochemical effects of g-C3N4 and PANI using cyclic voltammetry (CV) and amperometry revealed that the g-C3N4-PANI hybrid composite enhanced the sensitivity, selectivity, stability, and accuracy of fentanyl measurement. With a sensitivity of 0.45445 μA/μM, the electrochemical measurements revealed a broad and consistent linear range spanning from 10 to 920 μM. The detection threshold was established at 0.006 μM. Additionally, its performance was assessed using several real-samples made from athlete pee. The findings displayed satisfactory recovery values ranging from 90.00% to 98.00% and low relative standard deviation values (less than 4.74%) and demonstrated the g-C3N4/PANI nanocomposite-based biosensor has the potential to be an effective anti-doping control tool, opening the door for its practical use in maintaining the fairness and safety of competitive sports. The analysis of the nanocomposite showed that the combination of PANI and g-C3N4 resulted in a material with enhanced electrochemical properties, which contributed to the high performance of the biosensor.