Ratiometric fluorescence detection of bleomycin based on proximity-dependent fluorescence conversion of DNA-templated silver nanoclusters

Authors：Lingyuan Liu; Shuyun Zhu; Jing Sun; Meng Xia; Xian’en Zhao; Guobao Xu

Source：CHINESE CHEMICAL LETTERS, 2020.

DOI：10.1016/j.cclet.2020.07.015

• Ratiometric
• nanosensor
• DNA-templated silver nanoclusters
• Fluorescence transformation
• Bleomycin
• DNA scission

We design a ratiometric fluorescent sensing platform for bleomycin (BLM) by using proximity-dependent DNA-templated silver nanoclusters (DNA-AgNCs) probe. This ratiometric sensing system is constructed with DNA-AgNCs as single fluorophore. The proposed strategy is based on the two following facts: (1) a covert DNA can approach and transform the DNA-AgNCs with green emission (G-DNA-AgNCs) into red emission through hybridization reaction. (2) The specific cleavage of the convert DNA by BLM in the presence of Fe(II) inhibits the discoloration of G-DNA-AgNCs. Thus, benefiting from the specific recognition of BLM and unique properties of G-DNA-AgNCs, a highly-sensitive ratiometric sensor for BLM has been successfully developed. The detection limit is as low as 30 pmol/L. This label-free fluorescence probe possesses advantages of convenient synthetic process and low cost. Moreover, this ratiometric method has been applied to the detection of BLM in human serum samples, illustrating a promising tool for analysis of BLM in cancer therapy.
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A novel ratiometric strategy was designed for sensitive detection of BLM with proximity-dependent fluorescence transformation of DNA-AgNCs via DNA scission for the first time.