Characterizing the Quantum Confined Stark Effect in Semiconductor Quantum Dots and Nanorods for Single-Molecule Electrophysiology

TL;DR

This study enhances quantum confined Stark effect voltage nanosensors by developing a high throughput screening method, identifying top-performing nanorods, and measuring their rapid response suitable for neural activity recording.

Contribution

Introduces a high throughput screening approach for QCSE nanosensors and identifies Type II ZnSe CdS nanorods as optimal for fast, sensitive voltage detection.

Findings

Type II ZnSe CdS nanorods outperform other nanosensors

Achieved a 3.5 microsecond response time for voltage sensing

Response time limited by electronics, not nanorod properties

Abstract

We optimized the performance of quantum confined Stark effect QCSE based voltage nanosensors. A high throughput approach for single particle QCSE characterization was developed and utilized to screen a library of such nanosensors. Type II ZnSe CdS seeded nanorods were found to have the best performance among the different nanosensors evaluated in this work. The degree of correlation between intensity changes and spectral changes of the excitons emission under applied field was characterized. An upper limit for the temporal response of individual ZnSe CdS nanorods to voltage modulation was characterized by high throughput, high temporal resolution intensity measurements using a novel photon counting camera. The measured 3.5 us response time is limited by the voltage modulation electronics and represents about 30 times higher bandwidth than needed for recording an action potential in a neuron.