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

Abstract

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-).

Hydrothermal synthesis of nitrogen and boron doped carbon quantum dots with yellow-green emission for sensing Cr(vi), anti-counterfeiting and cell imaging

“…Moreover, the lowest detection concentration of Cr 2 O 7 2À was 0.5 mM, which was not comparable to that of the reported nanosensors for Cr 2 O 7 2À (Table S1 †). [20][21][22][23][24] However, the value was much below the allowed lowest concentration in drinking water set by the US Environmental Protection Agency. 21,22 Most importantly, the linear range is much wider than those reported results (Table S1 †), revealing that the NBCQDs have the potential to detect Cr 2 O 7 2À in some practical samples.…”

Gold nanoparticles as efficient sensors in colorimetric detection of toxic metal ions: A review

“…Meso-2, 3-dimercaptosuccinic acid (DMSA)-functionalized GNPs are reported to detect Cr 3+ and Cr2O7 2-by inducing cross linking between GNPs. They further integrated the system with a smart phone giving way to an innovative approach allowing lab-on-chip format for highly sensitive detection of Cr [86]. GNPs grown on thiol functionalized silicate network have also been found capable of detecting Cr 3+ ions and show a MDL of 0.1ppb [87].…”

Gold Nanoparticles for Diagnostics: Advances towards Points of Care

“…[117], which is of extreme relevance for epidemiological data gathered in isolate populations of remote areas in developing countries [118,119]. Tests for the detection of heavy metals, malaria, tuberculosis and for the quantification of vitamins (such as B 12 and D) and glucose have been reported by taking advantage of approaches relying on smartphones [61,117,119,120,121,122,123]. …”