Rapid and sensitive colorimetric sensing of the insecticide pymetrozine using melamine-modified gold nanoparticles

A colorimetric sensor for the pesticide pymetrozine (PYM) based on analyte-induced aggregation of melamine-modified gold nanoparticles (M-Au NPs) has been developed with high selectivity and sensitivity with a detection limit of 80 nM by the naked eye and 10 nM by UV-Vis spectroscopy. This colorimetric sensing design exhibits lower detection limits, compared with limits of 46-148 nM for existing instrumental methods. The new aggregation-induced nanoparticle sensor is applicable for rapid colorimetric detection of PYM in real water environments (tap water and lake water) and food samples (green tea and apple juice). The technical approach for the colorimetric sensor is easier and simpler than detection of PYM by, for example, HPLC whilst giving equivalent results within the error of the measurements.