Nanoscale in-vivo studies on the signaling of a broad range of neurotransmitters are essential to understand brain functions and diseases. In this talk, I will first describe our efforts in the development and creation of versatile electroanalytical liquid-liquid junction probes to enable the detection of redox-inactive transmitters. By using the liquid/liquid approach, we circumvent the challenges in the measurement of non-redox-active neurotransmitters using nano-electroanalytical methods. In addition, I will share our recent efforts in developing dual-channel nano-carbon-liquid/liquid junction electrodes for multi-modal analysis of both redox-active and non-redox-active analytes. Then I will present our studies on high spatiotemporal bioanalysis using model living organisms. We employed scanning electrochemical microscopy (SECM) to position our nanoprobes accurately with nm spatial resolution. Our results show that our nanoprobes, with sizes as small as 15 nm in radius, can detect and quantify the acetylcholine neurotransmission in real time, at a high spatiotemporal resolution, with a high signal-to-noise ratio, and in biologically relevant fluids. The nano/micro-electroanalytical platform we developed is enabling a variety of new measurements on signaling dynamics across a diverse range of length scales, i.e., at single cells, at single synapses, in living mice brains, and will create exciting opportunities in studying transmission from various neuronal models and in our understanding of neurological disorders from a distinctive perspective.


Acknowledgment: I am grateful to the Alfred P. Sloan Foundation, National Science Foundation, National Institutes of Health, Research Corporation for Science Advancement, Frederick Gardner Cottrell Foundation, The Paul G. Allen Frontiers Group, Chan-Zuckerberg Biohub Chicago, and the University of Illinois Urbana-Champaign for the support of our research. All the work that I will present is not possible without the hardworking and dedicated efforts of Shen group members.