Plasmonic colorimetry: visual detection of environmentally relevant species

Abstract

Colorimetric detection of chemical species based on specially tailored noble metal nanoparticles is garnering increasing interest in the scientific community. The aggregation/dispersion of unmodified or ligandfunctionalised plasmonic nanostructures upon binding to an environmental pollutant results in a colorimetric response, which can be easily discerned with the naked eye. This review offers a snapshot of recent advances in this field of plasmonic colorimetry. The identification and detection of anionic, neutral and cationic chemical species among a wide variety of other environmentally significant pollutants remains a particularly important but difficult challenge. The optical transduction of target-ligand interactions at the surface of plasmonic nanostructures via a distinct colour change is very attractive for the development of environmental sensors. Such a litmus test-type colorimetric transduction sensing scheme offers extreme simplicity and excellent robustness for practical applications.