title: DOPA-mediated reduction allows the facile synthesis of fluorescent gold nanoclusters for use as sensing probes for ferric ions.
abstract: In this paper, we describe a simple one-pot method, employing l-3,4-dihydroxyphenylalanine (L-DOPA) as a reducing/capping reagent, for the synthesis of fluorescent gold nanoclusters (AuNCs). Within a short reaction time of 15 min (excluding the time required for purification), this strategy allows the fabrication of homogeneous AuNCs having the capability to sense ferric ions (Fe(3+)). The as-prepared AuNCs exhibited a fluorescence emission at 525 nm and a quantum yield of 1.7%. On the basis of an aggregation-induced fluorescence quenching mechanism, these fluorescent AuNCs offer acceptable sensitivity, high selectivity, and a limit of detection of 3.5 μM for the determination of Fe(3+) ions, which is lower than the maximum level (0.3 mg L(-1), equivalent to 5.4 μM) of Fe(3+) permitted in drinking water by the U.S. Environmental Protection Agency.
authors.affiliation: BioAnalytical and Nanobiomedicinal Laboratory, Department of Biochemical Science and Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617 Taiwan. jaho@ntu.edu.tw
authors.forename: Ja-an Annie
authors.initials: JA
authors.lastname: Ho
authors.forename: Heng-Chia
authors.initials: HC
authors.lastname: Chang
authors.forename: Wen-Ta
authors.initials: WT
authors.lastname: Su
mesh_terms: D002021:Buffers; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D002712:Chlorides / Q000737:chemistry; D019587:Dietary Supplements / Q000032:analysis; D004295:Dihydroxyphenylalanine / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D017612:Gold Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D060106:Lakes / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D055620:Optical Phenomena; D010084:Oxidation-Reduction; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D002021:Buffers; D002712:Chlorides; D005456:Fluorescent Dyes; D017612:Gold Compounds; D014867:Water; D004295:Dihydroxyphenylalanine; D006046:Gold; C024568:gold tetrachloride, acid; D007501:Iron