Neurodegenerative diseases early detection and monitoring system for point-of-care applications

Abstract

Millions of people worldwide are negatively impacted by a diverse range of brain conditions known as neurodegenerative diseases. The work reports a GaN HEMT-based biosensing system for the early detection and monitoring of neurodegenerative disease biomarkers in clinically relevant concentration ranges. The developed system offers a high sensitivity of 19.40 µA/pg/ml, 0.52 mA/pg/ml, 0.69 mA/ng/ml, 0.13 mA/pg/ml, 23.66 µA/pg/ml, and 23.85 µA/pg/ml for the detection of UCH-L1, GFAP, S100B, IL-6, Aβ, and IFN-γ respectively. The proposed biofunctionalization assay has an excellent specificity and selectivity, signal-to-noise ratio of 1:16, 1:23, and 1:38 for UCH-L1, GFAP, and S100B detection respectively with a LoD of 0.06 fg/ml. The platform has good repeatability with an average sensitivity of 19.41 µA/pg/ml, 0.524 mA/pg/ml, and 0.704 mA/ng/ml for UCH-L1, GFAP, and S100B detection respectively. The sensors have a very good shelf-life for a storage time of 35 days with reductions of 1.39 %, 1.72 %, and 2.05 % in sensor response and 2.88 %, 2.76 %, and 2.96 % in sensitivity for UCH-L1, GFAP, and S100B respectively. The coefficient of variation (CV) values for conventional and meander-gated GaN HEMT biosensors were found to be ∼0.038 and ∼0.026 respectively. A slight variation of ∼4.41 % in sensor response when the sensor was reused clearly demonstrates the sensor’s reusability. A very high resolution with detection capability in the ultra-low concentration of fg/ml with good linearity and quantifiable sensor response which is a key requirement for early-stage detection of diseases has been observed for sensor design with source-to-drain distance () of 10 µm. Thus, the platform capability and suitability for early detection and prognosis of neurodegenerative disease detection and monitoring have been demonstrated. Further, the system can be imperative in patient screening in clinical, sports, and warfare for CT or MRI scan requirements.