title: Colorimetric detection of iron ions (III) based on the highly sensitive plasmonic response of the N-acetyl-L-cysteine-stabilized silver nanoparticles.
abstract: We report here a facile colorimetric sensor based on the N-acetyl-L-cysteine (NALC)-stabilized Ag nanoparticles (NALC-Ag NPs) for detection of Fe(3+) ions in aqueous solution. The Ag NPs with an average diameter of 6.55±1.0 nm are successfully synthesized through a simple method using sodium borohydride as reducing agent and N-acetyl-L-cysteine as protecting ligand. The synthesized silver nanoparticles show a strong surface plasmon resonance (SPR) around 400 nm and the SPR intensity decreases with the increasing of Fe(3+) concentration in aqueous solution. Based on the linear relationship between SPR intensity and concentration of Fe(3+) ions, the as-synthesized water-soluble silver nanoparticles can be used for the sensitive and selective detection of Fe(3+) ions in water with a linear range from 80 nM to 80 μM and a detection limit of 80 nM. On the basis of the experimental results, a new detection mechanism of oxidation-reduction reaction between Ag NPs and Fe(3+) ions is proposed, which is different from previously reported mechanisms. Moreover, the NALC-Ag NPs could be applied to the detection of Fe(3+) ions in real environmental water samples.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Yizhong
authors.initials: Y
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Shuijian
authors.initials: S
authors.lastname: He
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
authors.forename: Xiaokun
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China. Electronic address: weichen@ciac.ac.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D002412:Cations / Q000032:analysis; D003124:Colorimetry / Q000379:methods; D007501:Iron / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*; D014867:Water / Q000032:analysis*
chemical_list: D002412:Cations; D014867:Water; D012834:Silver; D007501:Iron; D000111:Acetylcysteine
keywords: Chemical sensor; Colorimetric sensing; Iron ions; N-acetyl-l-cysteine; Silver nanoparticles; Surface plasmon resonance