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

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.