Rapid voltage sensing with single nanorods via the quantum confined Stark effect

TL;DR

This paper introduces a rapid, shot-noise limited detection method for quantum dot sensors exploiting the quantum confined Stark effect, enabling fast electric field measurements potentially suitable for neural activity detection.

Contribution

The authors develop a new detection scheme that significantly accelerates QCSE-based voltage sensing in quantum dots, achieving millisecond temporal resolution.

Findings

Demonstrated shot-noise limited sensitivity to emission wavelength shifts.

Achieved millisecond time-scale electric field detection.

Potential application in detecting neural action potentials.

Abstract

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 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 at achieving 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.