Aptamer-Based Electronic Neurochemical Sensor

This is the non-genetic route to molecularly-specific chemical sensing in the brain: a nucleic-acid aptamer, selected to bind a chosen target, is anchored to an electrode or transistor gate so that target binding changes a conformation and thereby a measurable electrical signal. Because the recognition element is a synthetic sequence rather than an enzyme, the same platform can, in principle, be retargeted to neurotransmitters, neuropeptides, metabolites, or drugs for which no enzymatic or genetically-encoded sensor exists.

The frontier goal is continuous, real-time, molecule-specific readout in an implanted sensor, going beyond the redox-limited scope of fast-scan voltammetry and the slow, discrete sampling of microdialysis. The unsolved problems are chronic biofouling, drift, and calibration in living tissue, so present demonstrations are strongest acutely or ex vivo; robust multi-week neurochemical sensing in the brain remains an open engineering challenge.