AIE based fluorescent self assembled glycoacrylamides for E.coli detection and cell imaging

摘要

Development of fluorescent glycopolymeric probes with high water solubility, multivalency, stimuli responsiveness, high cellular internalization efficiency and good photostability, is in urgent demand. Aggregation Induced Emission (AIE) property of glucose based acrylamides (Glc-acryl and Glc-bis) have been studied at various pH, concentration and their application towards lectin recognition, bacterial detection and cell imaging have been probed. The emissions of glycoacrylamides are found to be pH dependent and exhibit Aggregation Induced Emission Enhancement (AIEE) in t-butanol-water mixtures. Fluorescent assay unravelled the specific recognition property of pendant glucose residues on glycoacrylamides towards protein, Concanavalin A (Con A), with an association constant (K_a) of 144 × 10~3 M~(-1) and 76.3 × 10~3 M~(-1), for the interaction with Glc-acryl and Glc-bis, respectively. The limit of detection (LOD) of Con A by Glc-acryl and Glc-bis was found to be 7.85 pM and 3.49 nM, respectively. Incubation with E.coli revealed that the relationship between the fluorescence signal and E.coli concentration was linear from (1.00 × 106) to (1.70 × 10~8) cells/mL (R~2 =0.98) with LOD (at S/N ratio of 3) of E.coli being 7.30 × 10~5 cells/mL The cell penetration studies of synthesized glycoacrylamides with INT407 cell lines showed good cellular uptake.