Specific and sensitive colorimetric detection of Al³⁺ using 5-mercaptomethyltetrazole capped gold nanoparticles in aqueous solution

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• 作者：Dingshuai Xue ; Hongyue Wang ; Yanbin Zhang
• 关键词：Al3+ ; Colorimetric detection ; Gold nanoparticles ; 5-mercaptomethyltetrazole
• 刊名：Talanta
• 出版年：15 February, 2014
• 年：2014
• 卷：119
• 期：Complete
• 页码：306-311
• 全文大小：1560 K

文摘

Contamination of food and drinking water by health-risk levels of Al³⁺ calls for convenient assays. Here, we report a method to visibly detect Al³⁺ 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 Al³⁺, the interparticle crosslinking induced aggregation (color change from red to blue) of MMT-AuNPs was triggered through the Al³⁺-MMT interaction. Under optimal conditions, the absorbance ratio (A₆₂₀/A₅₂₀) of MMT-AuNPs is linear within the Al³⁺ concentration range from 1.0 to 10.0 渭M, and the detection limit (3蟽) was as low as 0.53 渭M. Moreover, an interference study showed that this MMT-AuNP probe discriminated Al³⁺ from a wide range of environmentally dominant metal ions and anions. The practical utility of the new method was demonstrated by determining Al³⁺ 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 Al³⁺ in routine laboratory practice or rapid on-site assay.