Near-IR intracellular Pd0/Pd2+ triggered de-allylation switch based on self-assembled perylene diimide

Abstract

In this report, we have synthesized and characterized novel dibromo allyl substituted perylene diimide (PDI-BA) for the selective detection of palladium species. PDI-BA showed solvatofluorism properties and can be used for mapping of moisture content (>5%) in CH3OH. The near-IR emission of PDI-BA was selectively disturbed by Pd0/Pd2+ species at concentrations as low as 17.2 nM and 286 nM, respectively. The PDI-BA showed ratiometric absorbance (A732nm/A548nm) changes upon addition of Pd0/Pd2+ with limit of detection as low as 97.3 nM/284 nM associated with color change from pink to green. Interestingly, no reducing agent is required for the Pd2+ induced de-allylation process. In the aggregated state (80% water), PDI-BA is 55 times more sensitive for Pd0 in comparison to its monomeric state (20% water). We further demonstrated the applications of PDI-BA for intracellular (L929 live cells) and pharmaceutical sample detection of Pd0 and Pd2+ species. The self-assembled aggregates of PDI-BA with morphology of holes disintegrates into spherical structures as confirmed by DLS and AFM techniques.