title: Specific and sensitive colorimetric detection of Al3+ using 5-mercaptomethyltetrazole capped gold nanoparticles in aqueous solution.
abstract: Contamination of food and drinking water by health-risk levels of Al(3+) calls for convenient assays. Here, we report a method to visibly detect Al(3+) at room temperature. Firstly, the chelating ligand of 5-mercaptomethyltetrazole (MMT) was synthesized and modified on the surface of AuNPs through the strong Au-S interaction to form a MMT-AuNP probe, which can remain well-dispersed and stable in an aqueous solution for a long time. Upon the addition of Al(3+), the interparticle crosslinking induced aggregation (color change from red to blue) of MMT-AuNPs was triggered through the Al(3+)-MMT interaction. Under optimal conditions, the absorbance ratio (A620/A520) of MMT-AuNPs is linear within the Al(3+) concentration range from 1.0 to 10.0 μM, and the detection limit (3σ) was as low as 0.53 μM. Moreover, an interference study showed that this MMT-AuNP probe discriminated Al(3+) from a wide range of environmentally dominant metal ions and anions. The practical utility of the new method was demonstrated by determining Al(3+) in several environmental water and human urine specimens, obtaining satisfactory results. Being a rapid, convenient and cost-effective method, it should become a powerful alternative to conventional methods for selective quantification of Al(3+) in routine laboratory practice or rapid on-site assay.
authors.affiliation: Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China. Electronic address: xuedingshuai@mail.iggcas.ac.cn.
authors.forename: Dingshuai
authors.initials: D
authors.lastname: Xue
authors.affiliation: Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Hongyue
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000535:Aluminum / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D012996:Solutions; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013777:Tetrazoles / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: C000591094:5-mercaptomethyltetrazole; D012996:Solutions; D013438:Sulfhydryl Compounds; D013777:Tetrazoles; D014867:Water; D006046:Gold; D000535:Aluminum
keywords: 5-mercaptomethyltetrazole; Al(3+); Colorimetric detection; Gold nanoparticles