Device Engineering of a Novel Label-Free Carbon and Double Gate-Based Sensor for PoC Diagnosis of Neural Diseases Through Dopamine and Serotonin Sensing

The manuscript discusses low-cost, rapid and diagnostic detection of dopamine and serotonin, whose abnormal levels lead to numerous neurological disabilities like Schizophrenia, Parkinson's disease, Huntington's disease and Alzheimer's disease. In this present work, simulation of three different proposed structures has been demonstrated for the detection of biomolecules: (a) amorphous carbon sensing material-based dopamine detection sensor, (b) graphite sensing material-based serotonin detection sensor and (c) double-gate FET structure for dopamine detection sensor. The cavities of amorphous carbon-based and graphite-based biosensors are expanded to 20 nm for better sensitivity. The amorphous carbon-based and graphite-based biosensors can detect dopamine and serotonin concentrations as low as 1.33 fM, respectively. In previous literature, an experimental electrochemical study has been done using 3-electrode set-up using amorphous carbon coated pencil graphite electrode as working electrode for dopamine detection. The results of an experimental electrochemical study are validated with the suggested amorphous carbon-based and graphite-based biosensors' sensitivity to various dopamine and serotonin concentrations. The sensing materials employed in this study: amorphous carbon and graphite are both readily available and cost-effective. Additionally, from the discussion it has been observed that the proposed devices exhibit significantly different sensitivity levels compared to existing designs. A novel double gate FET structure device has been also proposed for detecting dopamine by introducing cavities in Hafnium dioxide so that biomolecules present in those cavities can be sensed by observing change in the drain current. The previous published work has been compared to the suggested detection method. Dopamine and serotonin are the neurotransmitters that are essential to the human body's neurological, hormonal and renal systems, hence these proposed approaches can be utilized for point of care diagnosis