Detection of Organic Pollutants by Using SERS based Sensors on Functionalized Metal Nanoparticles

Abstract

Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs) are harmful to humans health and polluted the environment. In recent years, great research interest has been focused on the detection and removal of these pollutants, in which techniques that are able to detect these compounds in trace amounts are essential. POPs have been found in every part of the world, even in remote area. Soil is the primary environmental reservoir for semi-volatile organic compounds like POPs. Because of their persistence and hydrophobicity (lack of affinity of water), POPs accumulate in soils where they can be retained for many years after their application. Through the soil-air-plant-animal-human pathway, human can be negative impact on health. Hence the detection and removal of these pollutants are highly necessary. A highly sensitive surface-enhanced Raman scattering (SERS) platform for the detection of POPs such as PCBs was reported. SERS was used to detect some organics at trace level using nanostructures of Nobel metals (Cu, Ag and Au) as the substrate. Nanostructure materials exhibit many interesting properties and may have potential in the detection of trace amounts of organic pollutants. Recently methods involving Au NPs have been used to perform trace analysis of organic pollutant. NPs are functionalized with various chemical groups to increase their affinity towards target compounds. Au NPs were synthesised and functionalized by using various functionalized materials such as and#946; Cyclodextrin (and#946;-CD), Glutathione (GSH), Titanium Oxide (TiO2), Zinc Oxide (ZnO) and Platinum (Pt). The optical, structural, vibrational and morphological properties of the prepared functionalized nanoparticles were studied. To detect the organic pollutant such as PCBs by using Gas Chromatography and Mass Spectrometry (GC-MS) and it is further verified and its isomers were detected by using SERS technique from different soil collected from different parts of Kodaikanal, Tamil Nadu. Functionalized SERS substrate materials used in