Properly designed colloidal semiconductor quantum dots (QDs) have already been shown to exhibit high sensitivity to external electric fields via the quantum confined Stark effect (QCSE). Yet, detection of the characteristic spectral shifts associated with the effect of the QCSE has traditionally been painstakingly slow, dramatically limiting the sensitivity of these QD sensors to fast transients. We experimentally demonstrate a new detection scheme designed to achieve shot-noise-limited sensitivity to emission wavelength shifts in QDs, showing feasibility for their use as local electric field sensors on the millisecond time scale. This regime of operation is already potentially suitable for detection of single action potentials in neurons at a high spatial resolution.
Bibliographical noteFunding Information:
The authors would like to thank K. Park for helpful discussions. The authors gratefully acknowledge funding by the Human Frontiers Science Project RGP0061/2015 and the European Research Council advanced grant NVS 669941. A.L. acknowledges support from the Marie Curie Individual Fellowship NanoVoltSens 752019. D.O. acknowledges support from the Crown Center of Photonics and the Israeli Centers of Research Excellence Program. S.W. acknowledges support by DARPA Fund #D14PC00141 and by the U.S. Department of Energy Office of Science, Office of Biological and Environmental Research program, under Award Number DE-FC02-02ER63421
Copyright © 2018 American Chemical Society.
- membrane potential sensing
- quantum confined Stark effect
- quantum dots