Optical nanosensors for intracellular sodium analysis

We have shown two types of nano-sized sensors, particle-based nano-sized sensors and quantum dot sensors capable of measuring the type of sodium dynamics that occur in cells. In these studies the sensors were loaded into cells using picoinjection. This minimizes the cell damage seen in electroporation and prevents the sensors from being trapped in endosomes as seen in the endocytotic loading. The sensors were loaded into cells containing voltage gated sodium channels and showed dispersion throughout the cytosol. Optical detection of sodium influx into the cell could be detected.