Rapid Dopamine Test to Enable Early Detection of Neurological Disorders

Neurotransmitters are essential for regulating neural function and overall well-being in humans and animals, ensuring a balanced hormonal environment for optimal body functioning. Dopamine is particularly critical, significantly influencing cognitive functions like motor skills and emotions such as happiness and pleasure. Apart from its role in regulating emotions, dopamine also acts as a biomarker for screening certain cancers and neurological disorders. Variations in dopamine levels are linked to a range of neurodegenerative diseases, including Parkinson’s and Alzheimer’s, as well as neurodevelopmental and psychological disorders like ADHD, Tourette’s Syndrome, bipolar disorder, and schizophrenia. Accurate measurement of dopamine levels is crucial for advancing both pharmaceutical research and clinical therapies. Now, a newly developed integrated optical sensor capable of detecting dopamine directly from unprocessed blood samples offers a cost-effective and efficient method for screening various neurological conditions and cancers, thus potentially enhancing patient outcomes.

The plasmonic sensor developed at University of Central Florida (Orlando, FL, USA) utilizes a small gold pattern that causes electrons to oscillate collectively in what are known as plasmons, intensified by a specific optical setup. The introduction of a molecule to the sensor's environment alters electron movement, modifying the light reflection off the sensor and facilitating molecule detection. In contrast to traditional biosensors that depend on biological components such as antibodies or enzymes, this novel sensor employs a specially crafted aptamer, a synthetic DNA strand, that targets dopamine specifically. This design not only reduces costs and extends the shelf life of the sensor but also allows for the direct detection of dopamine in unprocessed blood, eliminating the need for sample preparation. This innovation is particularly valuable in resource-limited settings, simplifying the diagnostic process and potentially allowing for the detection of other conditions using similar technology.

Image: The integrated optical sensor is capable of detecting dopamine directly from an unprocessed blood sample (Photo courtesy of Professor Debashis Chanda)

The researchers optimized molecule detection by applying an aptamer to the sensor's active area, designed to bind precisely to targeted biomarkers. The findings published in Science Advances, demonstrate the sensor's ability to rapidly and accurately diagnose diseases. This advancement builds on previous work where the team enhanced the sensor’s selectivity and broadened its clinical applications by substituting cerium oxide nanoparticles with DNA-based aptamers, thus enabling the direct detection of dopamine in various biological samples without the need for prior sample preparation.

“This plasmonic biosensor is extremely sensitive to low concentrations of biomolecules, which make them promising platform for specialized assays, point of care applications in remote locations,” said UCF NanoScience Technology Center Professor Debashis Chanda, the study’s principal investigator. “In this work, we demonstrated an all-optical, surface-functionalized plasmonic biosensing platform for the detection of low concentrations of neurotransmitter dopamine directly from diverse biological samples which includes protein solutions, artificial cerebrospinal fluid, and unprocessed whole blood.”

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