High temporal resolution electrochemical biosensor using nitrogen-incorporated nanodiamond ultra-microelectrode array

Biosensors for detecting/measuring/monitoring the concentration of neurotransmitters that vary at sub-second time-scale can be achieved by using an electrode with high temporal resolution and fast electron transfer kinetics. Neurotransmitters, such as dopamine, undergo rapid fluctuations in concentrations occurring at a sub-second time scale. Real-time monitoring and measurement of these concentrationn changes, in-vivo or in-vitro, requires the use of ultra-microelectrode array (UMEA). This work reports on the development of a reliable UMEA electrochemical biosensor which can be used to identify, quantify, and monitor essential bio-analytes such as dopamine (DA), ascorbic acid (AA) and uric acid (UA) by using CVD nitrogen-incorporated nanodiamond UMEA without the need of electrode surface functionalization or modifications, making real-time detection possible. The application of fast-scan voltammetry (FSCV) for detecting dopamine and interfering bio-chemicals, including ascorbic acid and uric acid in 0.1M PBS (pH 7.4) by the UMEA has been realized. The detailed experiential method for the sensor array fabrication, and the UMEA sensitivity, selectivity, and detection limit for the detection of bio-analytes will be discussed.