Detection of the nanomolar level of total Cr[(iii) and (vi)] by functionalized gold nanoparticles and a smartphone with the assistance of theoretical calculation models

• DOI: 10.1039/c4nr06726f
• Publication Date: 2014-12-15T09:02:47Z
• Authors: Wenwen Chen; Fengjing Cao; Wenshu Zheng; Yue Tian; Yunlei Xianyu; Peng Xu; Wei Zhang; Zhuo Wang; Ke Deng; Xingyu Jiang
• Keywords: Chromium; Ions; Metal Nanoparticles; 02 engineering and technology; Models, Theoretical; Limit of Detection; Metals; Spectrophotometry; Soil Pollutants; Thermodynamics; Gold; Smartphone; Succimer; 0210 nano-technology

We report a method for rapid, effective detection of both Cr(iii) and Cr(vi) (in the form of Cr(3+) and Cr2O7(2-), the main species of chromium in the natural environment) by making use of meso-2,3-dimercaptosuccinic acid (DMSA)-functionalized gold nanoparticles (Au NPs). The limit of detection (LOD) is 10 nM with the naked eye and the assay can be applied in detecting chromium in polluted soil from Yun-Nan Province in Southwest China. We use density functional theory to calculate the change of the Gibbs free energy (ΔG) of the interactions between the DMSA-Au NP system and various metal ions, which shows that DMSA-Au NPs have high specificity for both Cr(3+) and Cr2O7(2-).