Sulfur-doped graphitic carbon nitride/cerium tungstate nanocomposites for ultrasensitive dopamine sensing in mouse...

Following the COVID-19 pandemic, the demand for rapid diagnostic tools for the highly specific and sensitive detection of disease-related biomarkers has increased significantly. Hybrid nanocomposite-modified disposable screen-printed electrodes have shown remarkable potential for the electrochemical biosensing of various biomarkers. This study reports the fabrication of a hybrid nanocomposite comprising sulfur-doped graphitic carbon nitride (S-g-C₃N₄) nanosheets integrated with two-dimensional cerium tungstate (CeW) for highly sensitive electrochemical dopamine detection. The synthesized S-g-C₃N₄@CeW hybrid nanocomposite was thoroughly characterized using field-emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and electrochemical measurements. Electroanalytical performance was evaluated using differential pulse voltammetry (DPV) under optimized experimental conditions. The fabricated electrochemical sensor exhibited a wide linear concentration range for dopamine from 0.1 to 500 μM, with a low detection limit of 1.13 nM and high sensitivity of 151.69 μA μM^-1 cm^-2. Finally, the fabricated sensor was used for the ex-vivo determination of dopamine in Parkinson's disease-induced mouse striatum-tissue samples, achieving good accuracy with recovery rates of 92.0 to 101.4%. This study demonstrates a promising strategy for fabricating hybrid nanocomposite-modified disposable electrochemical sensors for neurotransmitter detection in animal-disease models.