Recent progress in detection of chemical and biological toxins in Water using plasmonic nanosensors

Abstract The supply of safe drinking water is one of the prominent challenges of the world. Water is polluted mainly by chemical and biological toxins which can causes a serious threat to ecosystems and human health. Regular monitoring of chemical and biological toxins in water sources is the primary step in any preventive method. Traditional detection methods include adsorption and chromatography coupled with mass spectrometry. The devices based on these techniques are not easy to be carried for on-site detection and require laborious sample preparation protocols. However, advancements in nanomaterial-based sensors have provided solutions to these challenges. Recent developments in plasmonic sensors lead to extraordinary advancements in the area of ultra-sensitive detection at the single particle or molecular level. Noble metal nanoparticles of gold (Au) and silver (Ag) exhibit excellent plasmonic properties and have been applied for the selective and label-free detection of very low concentrations of aquatic pollutants. The present review represent the progress made towards the development and application of plasmonic nanosensors, specifically gold and silver nanoparticle-based sensors for the detection and quantification of various pollutants and contaminations in water. The design and fabrication of plasmonic nanosensors were given emphasis as it is fundamental in enhancing their affinity towards specific pollutant of interest. The effectiveness of plasmonic sensors in reducing the use of expensive instruments while enabling on-site multifunctional detection of toxin contaminants and also the future potential of plasmonic sensors will be highlighted.