Controllable stimulation of retinal rod cells using single photons

TL;DR

This study demonstrates the ability to stimulate retinal rod cells with single photons, providing direct evidence of their quantum sensitivity and measuring their efficiency without pre-calibrated detectors, advancing quantum biology research.

Contribution

It introduces a novel method to interface single-photon light sources with biological cells and measures quantum efficiency without relying on statistical models or pre-calibrated detectors.

Findings

Retinal rod cells are sensitive to single photons.

Quantum efficiency of rod cells is approximately 29%.

The method enables future quantum studies in vision and photosynthesis.

Abstract

New tools and approaches of quantum optics offer a unique opportunity to generate light pulses carrying a precise number of photons. Accurate control over the light pulses helps to improve the characterization of photo-induced processes. Here, we interface a specialized light source which provides flashes containing just one photon, with retinal rod cells of Xenopus laevis toads. We provide unambiguous proof of single photon sensitivity of rod cells without relying on the statistical modeling. We determined their quantum efficiencies without the use of any pre-calibrated detectors, and obtained the value of 29+-4.7 %. Our approach provides the path for future studies and applications of quantum properties of light in phototransduction, vision, and photosynthesis.