Analyzing Functionalized Carbon Quantum Dots in Electrode Engineering for the Precise Electrochemical Detection of a Neurotransmitter: Achieving Laboratory Accuracy with Portable Sensors

Point-of-care testing (POCT) devices are revolutionizing health monitoring by enabling rapid and accessible testing outside conventional laboratory environments. However, achieving laboratory-level accuracy in these portable devices continues to pose a significant challenge. This study introduces e-Patram, an innovative paper-based POCT sensor specifically designed for the precise and efficient monitoring of dopamine (DA) in urine, a critical biomarker for neurological health. Regular monitoring of DA is essential for identifying fluctuations that may signal neurodegenerative conditions, such as Parkinson's disease, and e-Patram aspires to facilitate early detection through noninvasive testing. The sensor utilizes electrochemical methods to attain high selectivity for DA, even in the presence of common interfering substances like ascorbic acid (AA) and uric acid (UA), which are often present in urine and can complicate electrochemical detection due to the close value of their redox potential with DA. By overcoming these interference challenges with the modification of the electrode, e-Patram provides reliable DA measurements with accuracy comparable to the standard "catecholamine test." Extensive validation with human urine samples confirms the device's precision and consistency, underscoring its potential as a practical and accessible tool for routine DA monitoring in both clinical and everyday settings.