Shikha Shalini, Dureja Samit, Sapra Rachit, Babu Jisha, Haridas V, Pattanayek Sudip K
Department of Chemical Engineering, IIT Delhi Hauz Khas New Delhi 110016 India
Department of Chemistry, IIT Delhi Hauz Khas New Delhi 110016 India.
RSC Adv. 2021 Sep 30;11(51):32286-32294. doi: 10.1039/d1ra06911j. eCollection 2021 Sep 27.
Understanding the interactions between nanoparticles and organophosphates is the key to developing cost-effective colorimetric pesticide detection. We have studied the interaction between three different organophosphates containing the P[double bond, length as m-dash]S group and borohydride stabilized silver nanoparticles. Three different organophosphates, namely phorate, chlorpyrifos, and malathion, have been used. The colorimetric changes are corroborated with UV-visible absorption studies along with the change in particle size and zeta potential. This effect persists in the presence of NaCl solution also. The chlorpyrifos and malathion do not show significant interactions with uncapped nanoparticles over time, while phorate undergoes degradation due to the scission of the S-CH linkage. A reaction mechanism, wherein a silver and sulfur (Ag→S) complex is formed, which is in agreement with Raman spectroscopic studies is proposed. The orientations of phorate near Ag nanoparticles are discussed from the adsorption energy calculation using density functional theory.
了解纳米颗粒与有机磷酸酯之间的相互作用是开发具有成本效益的比色法农药检测的关键。我们研究了三种含有P[双键，长度为中划线]S基团的不同有机磷酸酯与硼氢化物稳定的银纳米颗粒之间的相互作用。使用了三种不同的有机磷酸酯，即甲拌磷、毒死蜱和马拉硫磷。比色变化通过紫外可见吸收研究以及粒径和zeta电位的变化得到证实。在NaCl溶液存在的情况下，这种效应也会持续存在。随着时间的推移，毒死蜱和马拉硫磷与未封端的纳米颗粒没有显示出明显的相互作用，而甲拌磷由于S-CH键的断裂而发生降解。提出了一种反应机理，其中形成了银和硫（Ag→S）络合物，这与拉曼光谱研究一致。利用密度泛函理论通过吸附能计算讨论了甲拌磷在银纳米颗粒附近的取向。
