Singlet oxygen luminescence detection with a fiber-coupled superconducting nanowire single-photon detector

TL;DR

This paper demonstrates the use of a superconducting nanowire single-photon detector to directly detect singlet oxygen luminescence at 1270 nm, advancing clinical monitoring techniques like photodynamic therapy.

Contribution

It introduces a fiber-coupled superconducting nanowire detector for sensitive infrared singlet oxygen detection, enabling in vivo applications.

Findings

Successful detection of 1O2 luminescence at 1270 nm

Verification of 1O2 signal using spectral filtering and quenching

Detection of 1O2 through a single optical fiber

Abstract

Direct monitoring of singlet oxygen (1O2) luminescence is a particularly challenging infrared photodetection problem. 1O2, an excited state of the oxygen molecule, is a crucial intermediate in many biological processes. We employ a low noise superconducting nanowire single-photon detector to record 1O2 luminescence at 1270 nm wavelength from a model photosensitizer (Rose Bengal) in solution. Narrow band spectral filtering and chemical quenching is used to verify the 1O2 signal, and lifetime evolution with the addition of protein is studied. Furthermore, we demonstrate the detection of 1O2 luminescence through a single optical fiber, a marked advance for dose monitoring in clinical treatments such as photodynamic therapy.