title: Selective detection of iodide and cyanide anions using gold-nanoparticle-based fluorescent probes.
abstract: We developed two simple, rapid, and cost-effective fluorescent nanosensors, both featuring bovine serum albumin labeled with fluorescein isothiocyanate (FITC))-capped gold nanoparticles (FITC-BSA-Au NPs), for the selective sensing of cyanide (CN(-)) and iodine (I(-)) ions in high-salinity solutions and edible salt samples. During the preparation of FITC-BSA-Au NP probes, when AuNPs were introduced to the mixture containing FITC and BSA, the unconjugated FITC and FITC-labeled BSA (FITC-BSA) adsorbed to the particles' surfaces. These probes operated on a basic principle that I(-) and CN(-) deposited on the surfaces of the Au NPs or the etching of Au NPs induced the release of FITC molecules or FITC-BSA into the solution, and thus restored the florescence of FITC. We employed FITC-BSA to protect the Au NPs from significant aggregation in high-salinity solutions. In the presence of masking agents such as S(2)O(8)(2-)/Pb(2+), FITC-BSA-Au NPs facilitated the selective detection of CN(-) (by at least 150-fold in comparison with other anions). We also demonstrated that the FITC-BSA-Au NPs in the presence of H(2)O(2) could selectively detect I(-) down to 50 nM. Taking advantages of their high stability and selectivity, we employed our FITC-BSA-Au NP-based probes for the detection of CN(-) and I(-) in water samples (pond water, tap water, and seawater) and detection of I(-) in edible salt samples, respectively. This simple, rapid, and cost-effective sensing system appears to demonstrate immense practical potential for the detection of anions in real samples.
authors.affiliation: Institute of Bioscience and Biotechnology, National Taiwan Ocean University, 2 Beining Road, Keelung 20224, Taiwan.
authors.forename: Shih-Chun
authors.initials: SC
authors.lastname: Wei
authors.forename: Pang-Hung
authors.initials: PH
authors.lastname: Hsu
authors.forename: Yen-Fei
authors.initials: YF
authors.lastname: Lee
authors.forename: Yang-Wei
authors.initials: YW
authors.lastname: Lin
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Huang
mesh_terms: D000838:Anions / Q000737:chemistry; D003486:Cyanides / Q000032:analysis*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold; D006861:Hydrogen Peroxide / Q000737:chemistry; D007454:Iodides / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry
chemical_list: D000838:Anions; D003486:Cyanides; D005456:Fluorescent Dyes; D007454:Iodides; C039217:fluorescein isothiocyanate bovine serum albumin; D014867:Water; D012710:Serum Albumin, Bovine; D006046:Gold; D006861:Hydrogen Peroxide; D016650:Fluorescein-5-isothiocyanate