Department of Chemistry, Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India.
Department of Applied Sciences, University Institute of Engineering & Technology (U.I.E.T.), Panjab University, Sector-25, Chandigarh 160014, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 May 5;196:268-273. doi: 10.1016/j.saa.2018.02.007. Epub 2018 Feb 5.
In the present study, we report a highly sensitive, rapid and low cost colorimetric monitoring of malathion (an organophosphate insecticide) employing a basic hexapeptide, malathion specific aptamer (oligonucleotide) and silver nanoparticles (AgNPs) as a nanoprobe. AgNPs are made to interact with the aptamer and peptide to give different optical responses depending upon the presence or absence of malathion. The nanoparticles remain yellow in color in the absence of malathion owing to the binding of aptamer with peptide which otherwise tends to aggregate the particles because of charge based interactions. In the presence of malathion, the agglomeration of the particles occurs which turns the solution orange. Furthermore, the developed aptasensor was successfully applied to detect malathion in various water samples and apple. The detection offered high recoveries in the range of 89-120% with the relative standard deviation within 2.98-4.78%. The proposed methodology exhibited excellent selectivity and a very low limit of detection i.e. 0.5pM was achieved. The developed facile, rapid and low cost silver nanoprobe based on aptamer and peptide proved to be potentially applicable for highly selective and sensitive colorimetric sensing of trace levels of malathion in complex environmental samples.
在本研究中，我们报告了一种基于碱性六肽、马拉硫磷特异性适体（寡核苷酸）和银纳米粒子（AgNPs）的高灵敏度、快速和低成本比色监测马拉硫磷（一种有机磷杀虫剂）的方法。AgNPs 与适体和肽相互作用，根据是否存在马拉硫磷，给出不同的光学响应。由于适体与肽的结合，纳米粒子在不存在马拉硫磷的情况下保持黄色，否则由于基于电荷的相互作用，肽往往会使粒子聚集。在马拉硫磷存在下，粒子发生团聚，溶液变为橙色。此外，所开发的适体传感器已成功用于检测各种水样和苹果中的马拉硫磷。该检测方法的回收率在 89-120%范围内，相对标准偏差在 2.98-4.78%范围内。该方法表现出优异的选择性和非常低的检测限，即达到 0.5pM。基于适体和肽的这种简便、快速且低成本的银纳米探针被证明可用于复杂环境样品中痕量马拉硫磷的高选择性和灵敏比色传感。
