Gold nanoparticle-based optical sensors for selected anionic contaminants

Nano-sensors have received intensive attention due to their unique sensitivity and selectivity, which mainly originate from modifications and reactions that occur at nano scales. An important ingredient for these sensors is gold nanoparticle which has been developed as the core material to detect anions, in particular in contaminated water. Especially these nano-sensors find specific applications for selected harmful anions which include a controlled anion F−, toxic contaminants CN− and AsO33−/AsO43−, and anionic fluorosurfactants. The anionic fluorosurfactants mainly include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), both of which have recently been listed as emerging contaminants and categorised as persistent organic pollutants. This review addresses recent advancements in the development of gold nanoparticle-based nano-sensors for such anions and outlines their performance limitations towards on-site applications.