Metal-free electrocatalytic nanocomposites of poly azovan blue-decorated graphitic carbon nitride for simultaneously sensing paracetamol and 4-aminophenol

Excessive consumption of paracetamol (PA) and 4-aminophenol (4-AP) can have harmful effects on the human body. This study developed a novel electroanalytical technique that utilizes the nanocomposites of poly azovan blue (PAB)-decorated graphitic carbon nitride (g-C₃N₄), deposited onto a screen-printed carbon electrode (SPCE), for the concurrent sensing of PA and 4-AP. The fabricated g-C₃N₄@PAB/SPCE exhibited exceptional synergistic effects, such as a high active electrochemical surface area and excellent electron transfer properties. The electrochemical behavior of g-C₃N₄@PAB/SPCE for simultaneous PA and 4-AP sensing was evaluated in the linear dynamic ranges of 0.08–75 and 0.05–90 μM, with the detection limits (S/N = 3) of 0.011 and 0.016 μM and sensitivities of 2.974 and 2.857 μA/μM/cm⁻² for PA and 4-AP, respectively. Additionally, g-C₃N₄@PAB/SPCE showed long-term stability, high reproducibility (RSD = 2.17%, n = 4), and superior anti-interference capabilities. Finally, when g-C₃N₄@PAB/SPCE was tested for simultaneously sensing both PA and 4-AP in tap water and artificial urine models, it exhibited satisfactory recoveries, demonstrating its potential use for various industrial and clinical applications.