Application of nanocrystalline CdTe quantum dots in chemical analysis: Implementation of chemo-sensing schemes based on analyte-triggered photoluminescence modulation

Abstract In the last decade, semiconductor quantum dots (QDs) have become valuable analytical tools in the development of novel photoluminescence-based approaches for the monitoring of a variety of analytes in biological samples, environmental monitoring, pharmaceutical analysis, food control, etc. The review addresses the state of the art in the development of CdTe-based nanomaterials and in the implementation of chemo-sensing schemes relying on the exploitation of their photochemical properties and reactivity. The main focus was the application of CdTe QDs involving a direct relationship between analyte sensing and QD photoluminescence modulation. Different strategies for adjusting this reactivity by means of surface modification or functionalization with suitable recognition groups allowing the targeting of specific analytes, are presented. The mechanisms involved in the QDs photoluminescence (PL) modulation associated to the analyte signaling process, such as charge and energy transfer, defects passivation, non-radiative recombination, etc, are also discussed.