title: A surface enhanced Raman scattering probe for highly selective and ultra sensitive detection of iodide in water and salt samples.
abstract: Iodine is a biophilic and essential trace element for all life and especially for vertebrates, which require it to produce indispensable thyroid hormones in their thyroid glands. As a result, the adequate measurement of iodine in water and food samples is crucial to lead a healthy life. Motivated by its importance, this is the first time in the literature that the highly selective and ultra sensitive (30 ppt limit) surface enhanced Raman scattering (SERS)-based detection of iodide ions (I(-)) from environmental and food samples has been reported. The desired sensitivity and selectivity has been achieved by measuring the change in the SERS intensity originating from Rh6G-adsorbed 30 nm gold nanoparticles (GNPs) upon the addition of I(-). The strong chemical affinity offered by I(-) towards the gold surface results in extra negative charge being deposited on it. As a result, the GNP surface attracts a greater number of positively charged Rh6G molecules and induces a marked increase in the number of hot spots through aggregation, providing a significant enhancement of the Raman signal intensity. The oxidation of I(-) to molecular iodine (I(2)) by hydrogen peroxide (H(2)O(2)) is employed for the successful screening of the bromide ion (Br(-)) which shows substantial interference at higher concentrations.
authors.affiliation: Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.
authors.forename: Samuel S R
authors.initials: SS
authors.lastname: Dasary
authors.forename: Paresh Chandra
authors.initials: PC
authors.lastname: Ray
authors.forename: Anant Kumar
authors.initials: AK
authors.lastname: Singh
authors.forename: Tahir
authors.initials: T
authors.lastname: Arbneshi
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yu
authors.forename: Dulal
authors.initials: D
authors.lastname: Senapati
mesh_terms: D007454:Iodides / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry; D012492:Salts / Q000032:analysis*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D014867:Water / Q000032:analysis*
chemical_list: D007454:Iodides; D012492:Salts; D014867:Water