Monitoring Single-Cell Neurotransmitter Exocytosis Using Carbonized Wood Electrochemical Sensors Reveals the Neurological Effects of Natural Products

For the first time, we have reported an electrochemical microsensor capable of quantitatively measuring the exocytosis of single living cells with a resolution sufficient to detect a single exocytotic event. Our technology offers a convenient, rapid, and quantitative method for studying the exocytosis of neurotransmitters in nerve cells. The sensor features a porous carbonized wood substrate with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 10\mu \mathrm{M}$</tex> pores above the size of a living SH-SY5Y cell (human neuroma cell line). It is enhanced with nanowires and metal-organic framework (MOF) probes, enabling comprehensive detection of exocytosis from all directions. Using this sensor, we rapidly measured how a flavonoid compound affects nerve cell exocytosis, uncovering crucial insights into their role in regulating neuronal activity and demonstrating the remarkable potential of the sensor for neuroscience research.