Fluorescein-Labeled Starch Maleate Nanoparticles as Sensitive Fluorescent Sensing Probes for Metal Ions

摘要

Fluorescein 5(6)-isothiocyanate starch maleate (FISM) nanoparticles were prepared by covalently attached fluorescein 5(6)- isothiocyanate (FITC) with starch maleate. FISM nanoparticles with a mean particle size of 87 nm were formed via self-assembly upon precipitation in ethanolic solution. FISM nanoparticles were strongly fluorescent with maximum emission wavelength of 518 nm. The fluorescence of FISMnanoparticles can be quenched by silver (Ag~+) and lead (Pb~(2+)) ions in a concentration dependent manner. We have demonstrated the first use of FISM nanoparticles as cheap and effective fluorescent sensing probes for Ag~+ and Pb~(2+) ions with detection limits as low as 2.55 × 10~(-5)M and 3.64 × 10~(-5) M, respectively.