Papers Abstract

Metal free bioimaging reagent for intracellular citrate in prostatecancer cells using aryl boronate derivative
A boronate group integrated on a triphenylimidazoleoxadiazolephenyl (TPIOP) moiety exhibited unusualsensing and detection abilities towards citrate. TPIOP boronate exhibited a bathochromic shift in itsfluorescence emission upon interaction with citrate. Quantification of trace levels of citrate ions in thehuman body may aid in the diagnosis of prostate cancer and kidney malfunctions. Herein, a novel, metal-free sensing strategy for citrate was developed based on fluorimetric detection with TPIOP boronate. Thefluorescence of TPIOP boronate increased linearly and was gradually red-shifted upon addition of citrate.The enhanced emission intensity was attributed to aggregation induced emission. The vacant ā€˜pā€™ orbitalof boron in TPIOP boronate acts as a Lewis acid, and accepts electrons from citrate, which is a Lewis base.Upon binding, the hybridization geometry of boron changes from sp2trigonal planar to sp3tetrahedral.The TPIOP boronate-citrate aggregates increase the polarity of TPIOP-boronate, which caused the redshift in the fluorescence. Citrate could be detected visually using a UV lamp, as the probe changed fromblue to green upon interaction with the analyte. The developed probe was applied for the visualizationof endogenous citrate in PC3 live cells.