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bioRxiv · 10.1101/2022.03.04.483061

Ultrasensitive Dopamine Detection with Graphene Aptasensor Multitransistor Arrays

Abrantes, M.·Rodrigues, D.·Domingues, T.·Nemala, S. S.·Monteiro, P.·Borme, J.·Alpuim, P.·Jacinto, L.
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Abstract

Dopamine is a neurotransmitter with critical roles in the human brain and body, and abnormal dopamine levels underlie brain disorders such as Parkinsons Disease, Alzheimers Disease, and substance addiction. Herein, we present a novel high-throughput biosensor based on graphene multitransistor arrays (gMTAs) functionalized with a selective aptamer for robust ultrasensitive dopamine detection. The miniaturized biosensor integrates multiple electrolyte-gated graphene field-effect transistors (EG-gFETs) in an array configuration, fabricated by high-yield reproducible and scalable methodologies optimized at the wafer level. With these gMTA aptasensors, we reliably detected ultra-low dopamine concentrations in physiological buffers, including undiluted phosphate-buffered saline (PBS), artificial cerebral spinal fluid (aCSF), and high ionic strength complex biological samples. We report a record limit-of-detection (LOD) of 1 aM (10-18) for dopamine in both PBS, and dopamine-depleted brain homogenate samples spiked with dopamine. The gMTAs also display wide sensing ranges across all media, up to 100 M (10-8), with a 22 mV/decade peak sensitivity in aCSF. Furthermore, we show that the gMTAs can detect minimal changes in dopamine concentrations in small working volume biological CSF samples obtained from a mouse model of Parkinsons Disease.

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Abrantes, M., Rodrigues, D., Domingues, T., Nemala, S. S., Monteiro, P., Borme, J., Alpuim, P., Jacinto, L.. 2022-03-06. Ultrasensitive Dopamine Detection with Graphene Aptasensor Multitransistor Arrays. https://doi.org/10.1101/2022.03.04.483061

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