Nitric oxide optical fiber sensor based on exposed core fibers and CdTe/CdS quantum dots

Nitric oxide plays a crucial role as a messenger in biological systems, but limitations in measurement are restricted due to its relatively low concentration and short half-life time. Here we report a novel approach to sensing nitric oxide by using an exposed core fiber with its core coated with CdTe/CdS core/shell quantum dots. This enables rapid detection and opens up the possibility of monitoring its production within biological systems. The detection mechanism is based on fluorescence quenching of CdTe/CdS quantum dots by nitric oxide, which can coordinate with Cd2+ directly as a ligand forming transition metal complexes. We demonstrate that CdTe/CdS quantum dots functionlization exposed core optical fibers can respond rapidly to nitric oxide in physiological environments with picomolar sensitivity.