title: Real-time scattered light dark-field microscopic imaging of the dynamic degradation process of sodium dimethyldithiocarbamate.
abstract: Single nanoparticle analysis (SNA) technique with the aid of a dark-field microscopic imaging (iDFM) technique has attracted wide attention owing to its high sensitivity. Considering that the degradation of pesticides can bring about serious problems in food and the environment, and that the real-time monitoring of the dynamic degradation process of pesticides can help understand and define their degradation mechanisms, herein we real-time monitored the decomposition dynamics of sodium dimethyldithiocarbamate (NaDDC) under neutral and alkaline conditions by imaging single silver nanoparticles (AgNPs) under a dark-field microscope (DFM); the localized surface plasmon resonance (LSPR) scattering signals were measured at a single nanoparticle level. As a result, the chemical mechanism of the degradation of NaDDC under neutral and alkaline conditions was proposed, and the inhibition effects of metal ions including Zn(II) and Cu(II) were investigated in order to understand the decomposition process in different environments. It was found that Cu(II) forms the most stable complex with NaDDC with a stoichiometric ratio of 1 : 2, which greatly reduces the toxicity.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Pharmaceutical Sciences, Southwest University, Chongqing 400716, P. R. China. liuhui78@swu.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Lei
authors.forename: Peng Fei
authors.initials: PF
authors.lastname: Gao
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
mesh_terms: D003300:Copper / Q000737:chemistry; D004125:Dimethyldithiocarbamate / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010575:Pesticides / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*; D015032:Zinc / Q000737:chemistry
chemical_list: D004125:Dimethyldithiocarbamate; D010575:Pesticides; D012834:Silver; D003300:Copper; D015032:Zinc