title: Citrate-capped platinum nanoparticle as a smart probe for ultrasensitive mercury sensing.
abstract: An 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.
authors.affiliation: Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou, Fujian 350004, China.
authors.forename: Gang-Wei
authors.initials: GW
authors.lastname: Wu
authors.forename: Shao-Bin
authors.initials: SB
authors.lastname: He
authors.forename: Hua-Ping
authors.initials: HP
authors.lastname: Peng
authors.forename: Hao-Hua
authors.initials: HH
authors.lastname: Deng
authors.forename: Ai-Lin
authors.initials: AL
authors.lastname: Liu
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Lin
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Xia
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D002951:Citrates / Q000737:chemistry*; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010984:Platinum / Q000737:chemistry*
chemical_list: D002951:Citrates; D010984:Platinum; D008628:Mercury