Fluorescent silver nanoclusters for user-friendly detection of Cu2+ on a paper platform

Abstract

The development of a user-friendly sensing platform for the detection of Cu²⁺ in water is necessary as there are wide concerns due to the substantial impact of Cu²⁺ on human health, environmental monitoring, and so on. Motivated by this, we report a fluorescent silver nanoclusters (AgNCs)-based sensor for the detection of Cu²⁺. These water-soluble AgNCs, as a new class of fluorescent probes, were synthesized by using azobenzene modified poly(acrylic acid) (MPAA) as templates. Their fluorescence can be quenched in the presence of Cu²⁺, which enables the label-free detection of Cu²⁺ in real water samples. Furthermore, such AgNCs can be integrated onto cellulose filter paper and used as fluorescent indicators for Cu²⁺. The fluorescence quenching can be observed by the naked eye under UV light. It should be noted that this AgNCs-based paper assay performs successfully in barrelled drinking water and river water samples. Therefore, it opens up new avenues to the development of robust clusters-based sensing platforms.