One-step synthesis of water-soluble fluorescent copper nanoparticles for label-free detection of manganese ions

This paper reports a one-step method for the synthesis of water soluble fluorescent copper nanoparticles stabilized by 3-mercaptopropoic acid and histidine. The resulting Cu nanoparticles exhibit intense blue fluorescence (λ_em = 449 nm), and proved highly effective in the selective detection of manganese ions. The intensity of Cu nanoparticle fluorescence was shown to decrease with an increase in manganese ion concentration in the range of 0.25–250 μM.