Low-cost graphite and double-gate FET-based label-free biosensor for dopamine sensing to detect neural diseases

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Dopamine is a critical neurotransmitter involved in neurological, hormonal, and renal systems.
• Disordered dopamine levels are associated with neurological conditions such as Alzheimer's and Parkinson's disease.
• Sensitive and accurate detection of dopamine is crucial for diagnosing and managing these neurological disorders.

Purpose of the Study:

• To propose and simulate novel biosensor structures for the detection of varying dopamine concentrations.
• To investigate the performance of graphite-based and double-gate TFET biosensors for dopamine detection.
• To enhance biosensor sensitivity through structural modifications and material selection.

Main Methods:

• Utilizing TCAD Silvaco software for the simulation of graphite-based and double-gate TFET structures.
• Analyzing the ON current (I_ON) sensing factor and its dependence on gate-source voltage (V_GS).
• Employing Bruggeman's model to calculate the effective dielectric constant for sensitivity analysis in double-gate FET sensors.

Main Results:

• A graphite-based biosensor demonstrated the ability to detect dopamine concentrations as low as 13.3 nM.
• Increasing the cavity size to 800 µm in graphite-based biosensors significantly improved sensitivity.
• Experimental electrochemical analysis validated the sensitivity of the proposed graphite-based biosensors.
• The double-gate FET biosensor showed increased sensitivity with higher dopamine and uric acid concentrations.

Conclusions:

• The developed graphite-based biosensors offer high sensitivity and potential for accurate dopamine detection.
• The double-gate FET biosensor design also shows promise for neurotransmitter sensing applications.
• These biosensor technologies could aid in the early diagnosis and monitoring of neurological diseases related to dopamine.