Citrate-Capped Platinum Nanoparticle as a Smart Probe for Ultrasensitive Mercury Sensing
2014; American Chemical Society; Volume: 86; Issue: 21 Linguagem: Inglês
10.1021/ac503544w
ISSN1520-6882
AutoresGang-Wei Wu, Shao‐Bin He, Hua‐Ping Peng, Hao‐Hua Deng, Ai‐Lin Liu, Xinhua Lin, Xing‐Hua Xia, Wei Chen,
Tópico(s)Mercury impact and mitigation studies
ResumoAn easily prepared platinum nanoparticle (PtNP) probe for the sensitive and selective detection of Hg(2+) ions is developed here. The PtNPs with an average size of approximately 2.5 nm were prepared by a reduction method with sodium borohydride and trisodium citrate serving as reductant and stabilizer, respectively. The resulting PtNPs could catalyze the reduction of Hg(2+) by surface-capping citrate. The effect of Hg(2+) uptake implies amalgam formation, which leads to remarkable inhibition of the peroxidase-like activity of citrate-capped PtNPs. On the basis of this effect, a colorimetric mercury sensor was established through the use of citrate-capped PtNPs to catalyze the colorimetric system of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2. The high specificity of the Hg-Pt interaction provides the excellent selectivity for Hg(2+) over interfering metal ions. The sensitivity of this smart probe to Hg(2+) is extremely excellent with a limit of detection (LOD) as low as 8.5 pM. In view of these advantages, as well as the cost-effectiveness, minimized working steps, and naked-eye observation, we expect that this colorimetric sensor will be a promising candidate for the field detection of toxic Hg(2+) ions in environmental, biological, and food samples.
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