Intercalated graphitic carbon nitride-modified electrochemical sensor for improved quercetin detection in clinical applications

•Synthesized nanostructure g-C3N4 as sensor materials for trace-level detection of Quarcetin (QRT).•Surface morphology and characterization of modifiers was studied by SEM, XRD, and AFM techniques.•The lowest detection limit (1.18 nM) was achieved for QRT.•The prototype developed was employed to the analysis of QRT in pharmaceutical samples. Novel voltammetric methodologies have been developed to facilitate the trace-level analysis of quercetin (QRT) using a graphitic nitride (g-C3N4) intercalated carbon sensor. The integration of g-C3N4 into the sensor matrix has enhanced its structural and surface properties, thereby increasing its sensitivity towards QRT detection. The catalytic behavior of g-C3N4 significantly influences the peak response observed for QRT. Systematic investigations were conducted to explore the influence of various parameters, such as scan rate, pH, pre-concentration time, modifier quantity, and analyte concentration, on the peak current response of QRT. Cyclic voltammetry was employed to evaluate the impact of the scan rate, which facilitated the determination of physicochemical parameters, including the heterogeneous rate constant (kₒ) and the number of electrons (n) involved in the electrochemical reaction. Additionally, the concentration effect of QRT was scrutinized using the Square Wave Voltammetry (SWV) technique, which exhibited superior detection sensitivity with a detection limit of 1.18 nM compared to existing methodologies. Furthermore, the g-C3N4/CPE was employed in real-time analysis of QRT in spiked urine samples and pharmaceutical tablet samples, showing satisfactory recovery results. The electrode also demonstrated good stability over multiple measurements, indicating that g-C3N4/CPE is a promising sensor for QRT detection.