Redox-Type Label-Free ATP Image Sensor for Highly Sensitive in Vitro Imaging of Extracellular ATP

Abstract

To decrease the limit of detection of imaging of extracellular ATP dynamics in the brain, we developed a redox-type, highly sensitive, label-free ATP image sensor with a reasonable spatial resolution ($37.3\ \ \mu\mathrm{m}$-pitch) effective utilization in in-vitro experiments. The lowest detectable concentration achieved in our sensor, which is based on hydrogen peroxide detection techniques using redox enzymes, was $3\ \mu \mathrm{M}$. Further, according to the results of the in-vitro biological experiment conducted using a 10 mM-HEPES buffer, our sensor demonstrated a 100 times superior performance compared to the existing imaging devices that were also based on hydrogen ion (H+) detection techniques. It is expected that our novel ATP image sensor can be successfully applied for highly sensitive imaging of ATP released from brain nerve tissues and cells. It also has potential application in the spatiotemporal analysis of ATP.