A thin-layer chromatography plate prepared from BODIPY-based receptor immobilized SiO2 nanoparticles as a portable chemosensor for Pb2+

A new fluorescence receptor based on BODIPY-immobilized silica nanoparticles (BODIPY-SiO2) exhibits a high affinity and selectivity for Pb2+ over competing metal ions in water. An overall emission change of ca. 100-fold at the emission maximum was observed for Pb2+. The fluorescence receptor BODIPY-SiO2 can remove 97% and 95% of the initial 100 ppb Pb2+ from human blood and waste solution, respectively. Experiments show the fluorescence receptor BODIPY-SiO2 can be a potentially useful and effective agent for the selective separation and rapid removal of Pb2+ in vivo. We also prepared a portable chemosensor kit by coating a 4 mu m thick film of BODIPY-SiO2 onto a glass substrate. We found that this BODIPY-SiO2 film detects Pb2+ ions at pH 7.4 with a sensitivity of 3.2 nM. Finally, we tested the effect of pH on BODIPY-SiO2 with Pb2+ ions between pH 3.0 and 11.0. The fluorescence changes of BODIPY-SiO2 were almost constant between pH 3 and 11. The results imply that the BODIPY-SiO2 film is applicable as a portable chemosensor for detection of Pb2+ ions in the environmental field.