The concentration of dopamine in a patient’s blood can be an important biomarker for a variety of diseases, including certain cancers, depression, and Parkinson’s. Measuring dopamine in whole blood still requires a laboratory, making it slow and expensive and not always suited for things like screenings.
Scientists at the University of Central Florida have now developed a portable, enzyme-free dopamine detector that takes just a sample of blood and which provides in a matter of minutes. It is hoped that the technology will be available for point-of-care applications, potentially making dopamine a common parameter even in general practice offices.
The device includes a microfluidic plasma separator that automatically prepares the sample for measurement by the biosensor. The biosensor is coated with cerium oxide nanoparticles that are attractive to dopamine, allowing it to settle on the sensor’s surface. As more of the dopamine sticks to the sensor, its reflectivity changes ever so slightly, a matter that can be detected using optical equipment.
From the study abstract in journal Nano Letters:
We obtain detection of dopamine at 100 fM concentration in simulated body fluid and 1 nM directly from blood without any prior sample preparation. The detection selectivity is found to be at least five-times higher compared to the common interfering species. This demonstration shows the feasibility of the practical implementation of the proposed plasmonic system in detection of variety of biomarkers directly from the complex biological fluids.