Synthesis And Applications Of BODIPY-Based Fluorescent Probes

Two BODIPY derivates AO-BODIPY and HHPBA-BODIPY fluorescent probes based on the recognition site of benzamidoxime and 2-hydroxy-N-?2-hydroxyphenyl?benzamide were synthesized.The photophysical properties of AO-BODIPY and HHPBA-BODIPY exhibit similar characters to the common BODIPY dyes.The emission spectra showed an intensive green fluorescence around 510 nm with a maximum absorption near 500 nm.AO-BODIPY can react to hypochlorite specifically and act as a hypochlorite fluorescent probe.The addition of hypochlorite results in a red-shift of absorption and emission spectra of the probe accompanied by a decrease of intensity.Spectra changes(A₅₀₀ and 1/I₅₁₂)of the probe can achieve a good linearity to the concentration of ClO^-.The fluorescence probe can react to ClO^-rapidly?within 60 s?in a wide pH range?4-10?with high sensitivity?detection limit of 6.81?M?and selectivity over other cations,anions,ROS and RNS.The reaction mechanism has been proposed and confirmed by MS analysis,ClO^-anion oxidizes amidoxime moiety to hydroxyl group and hydroxyl group is further oxidized to formyl group in the formation of a corresponding aldehyde compound.In addition,the probe has also been successfully applied to detect ClO^-in tap water and river water samples by spiking a known amount of standard ClO^-.AO-BODIPY did not response to uranyl ions although the amidoxime group can bind to uranyl specifically.It demonstrated that AO-BODIPY can bind to uranyl ions in chelating mode by the oxygen atom and nitrogen atom of amidoxime using the ¹HNMR spectra.HHPBA-BODIPY showed a good response to Cu²⁺.In the presence of Cu²⁺the fluorescence at 510 nm can be quenched and a good linearity can be achieved between the fluorescence intensity and the concentration of Cu²⁺with the detection limit of 0.35?M.Except for Fe³⁺and Cr³⁺,other common metal ions did not interfere with the detection of Cu²⁺.HHPBA-BODIPY showed a good recovery detecting Cu²⁺in water samples and thus it can be applied to detect trace amount of Cu²⁺for environmental monitoring.In addition,the absorption spectra and the emission spectra of HHPBA-BODIPY showed no sensing ability to uranyl ions.