An Accessible Approach to Preparing Water-Soluble Mn 2+ -Doped (CdSSe)ZnS (Core)Shell Nanocrystals for Ratiometric Temperature Sensing

Abstract

A new synthetic scheme allowing structural modifications to temperature-sensitive and watersoluble D-penicillamine-passivated Mn2+-doped (CdSSe)ZnS (core)shell nanocrystals (MnQDs) was reported using air-stable chemicals. The temperature-dependent optical properties of the nanocrystals were tuned by changing their structure and composition—the ZnS shell thickness and the Mn2+-dopant concentration. Thick ZnS shells significantly reduce the interference of nonradiative transitions on ratiometric emission intensities. High dopant concentration affords consistent temperature sensitivity. In addition to the new base structure for quantum dot ratiometric temperature sensing via flexible, glovebox-free routes, the results also underscore the generalizability of the emission intensity ratio scheme for temperature sensing, originally proposed for rare earth-doped materials.