CONDUCTIVE NANOCRYSTALLINE DIAMOND MICRO-ELECTRODE SENSORS AND ARRAYS FOR IN-VIVO CHEMICAL SENSING OF NEUROTRANSMITTERS AND NEUROACTIVE SUBSTANCES AND METHOD OF FABRICATION THEREOF
Conductive diamond micro-electrode sensors and sensor arrays are disclosed for in vivo chemical sensing. Also provided is a method of fabrication of individual sensors and sensor arrays. Reliable, sensitive and selective chemical micro-sensors may be constructed for real-time, continuous monitoring of neurotransmitters and neuro-active substances in vivo. Each sensor comprises a conductive microwire, having a distal end comprising a tip, coated with nanocrystalline or ultrananocrystalline conductive diamond, and an overlying insulating layer. Active sensor areas of the conductive diamond layer are defined by openings in the insulating layer at the distal end. Multiple sensor areas may be defined by a 2 or 3 dimensional pattern of openings near the tip. This structure limits interference from surrounding areas for improved signal to noise ratio, sensitivity and selectivity. Using fast-scan cyclic voltammetry and high speed multiplexers, multiple sensors can be arrayed to provide 3-D spatial, and near real-time monitoring.
