Nanocatalyst/Nanoplasmon‐Enabled Detection of Organic Mercury: A One‐Minute Visual Test

Abstract

We present a fast and sensitive nanosensor that can detect organic mercury, exploiting the combination of the catalytic and plasmonic properties of gold nanoparticles (AuNPs). The method is one‐step and completely instrument‐free, and has a colorimetric readout clearly detectable by simple visual inspection. The AuNPs catalyze efficient organic mercury reduction to the metallic form (Hg0), allowing its nucleation and amalgam formation on particle surface, with consequent aggregation‐induced plasmon shift. This leads to very rapid (1 min) and specific colorimetric detection of mercury species. The achieved limit of detection (20 ppb) is compliant with current regulatory limits in food.

Photodissociation Mechanisms of Major Mercury(II) Species in the Atmospheric Chemical Cycle of Mercury

“…After deposition into aquatic environments, inorganic mercury can be transformed into methylmercury, a potent neurotoxin harmful to the human population . Accordingly, Hg receives a great deal of attention …”

Biothiol-Functionalized Cuprous Oxide Sensor for Dual-Mode Sensitive Hg2+ Detection

“…The high-resolution XPS spectrum of Hg 4f reveals that the binding energies at 99.9 and 100.9 eV are assigned to Hg 4f 7/2 , and the binding energies at 103.9 and 104.9 eV correspond to Hg 4f 5/2 (Figure b). The peaks at 100.9 and 104.9 eV might be due to the formation of HgS, which can also be supported by the S 2p peaks. , As shown in Figure c, the peaks at 161.9 and 163.6 eV originate from S 2p 3/2 and S 2p 1/2 of HgS and Cu x S, respectively. , Except for N 1s (Figure S6c), the shift of the peak position and the variation of its intensity for C 1s (286.0 and 288.1 eV) and O 1s (531.7 eV) further illustrate that the carboxyl groups of l -Cys are also involved in the coordination with Hg 2+ ions (Figures d and S6b). The relative enhancement of the peak of Cu 2+ chemical state also confirms the competitive interaction of Hg 2+ and Cu + ions with biothiol (Figure S6a).…”

“…The peaks at 100.9 and 104.9 eV might be due to the formation of HgS, which can also be supported by the S 2p peaks. 56,57 As shown in Figure 6c, the peaks at 161.9 and 163.6 eV originate from S 2p 3/2 and S 2p 1/2 of HgS and Cu x S, respectively. 58,59 Except for N 1s (Figure S6c), the shift of the peak position and the variation of its intensity for C 1s (286.0 and 288.1 eV) and O 1s (531.7 eV) further illustrate that the carboxyl groups of L-Cys are also involved in the coordination with Hg 2+ ions (Figures 6d and S6b).…”

Colorimetric Nanoplasmonics to Spot Hyperglycemia From Saliva

“…In this framework, for example, gold nanoparticles (GNPs) present enormous potential for the development of a new generation of highly sensitive sensors (Liu and Lu, 2003;Luo et al, 2004;Pingarrón et al, 2008;Sperling et al, 2008;Zhang et al, 2012;Pompa, 2013, 2016;Howes et al, 2014;Chen et al, 2016;Valentini et al, 2017;Qin et al, 2018;Quesada-González and Merkoçi, 2018;Donati et al, 2019;Hao et al, 2019;Loynachan et al, 2019;Quesada-González et al, 2019), due to their unique size-, shape-, and dispersion-state-dependent plasmonic properties, which can be exploited for the realization of "naked-eye detection" assays (Baron et al, 2005;Wang et al, 2006;Song et al, 2011;Liu et al, 2012;Zhao et al, 2016;Donati et al, 2019;Lu et al, 2019;Xu et al, 2019). Common colorimetric approaches involve target-mediated GNP aggregation/assembly strategies or growth/etching processes Rao et al, 2019).…”