A persistent luminescent nanobeacon for practical detection of lead ions via avoiding background interference

Heavy metal ions are considered to be the most serious sources for water pollution. Accurate detection of metal ions is important for pollution control and ecological protection. Background interference is an inevitable obstacle in the fluorescent analysis of complex samples. Herein, a persistent luminescent nanobeacon is communicated to detect metal ions in real samples via avoiding background interference. The nanobeacon is constituted by persistent luminescence nanomaterials and metal-specific DNAzymes. As a proof of concept, Zn2GeO4: Mn persistent luminescence nanorods (PLNRs) was synthesized and functionalized with the 17E DNAzyme for lead ion (Pb2+) detection. As a result, in the luminescent manner, the nanobeacon could recognize Pb2+ selectively and detect it with high signal-to-background ratios (SBR) both in buffer and real samples, but the fluorescent SBR declined significantly when used in real samples. Thus, this persistent luminescent nanobeacon can achieve practical detection of metal ions via avoiding background interference. Compared to previous methods of improving signal-to-background ratio, this persistent luminescent nanobeacon is more accessible, and all DNAzyme-specific ions can be directly adapted.