Ultrasmall signal-amplified Ag 2 Se–imide hybrid fluorescence nanodots for the detection of trace DNA in mitochondria

摘要

Abstract(#br)DNA levels in mitochondria are closely related to serious genetic diseases, but their inherently low levels and high dynamic changes, present great obstacles to the precise detection of trace changes of DNA content in mitochondria, especially for living cells. This work aims to precisely detect DNA in mitochondria of living cells, by using ultrasmall fluorescent hybrid Ag 2 Se-imide nanodots (NDs) (< 3.0 nm, negative surface charge ζ= −29.2 mV) with signal amplification. The hybrid NDs are constructed by integrating naphthalene fluorophore in the Ag 2 Se core with a modified layer of chitooligosaccharide and bovine serum albumin (ACBH). The lowest detection for DNA is as low as 107.5 ng mL −1 . On the basis of multiple synergistic interactions, ACBH can specifically bind to mitochondrial DNA of living cells. ACBH can also emit an amplified signal (163-fold), which is beneficial for sensitivity analysis. Given its high sensitivity and selectivity, as well as signal amplification, ACBH can be used to in situ image trace DNA in the mitochondria of living cells. In particular, ACBH has been successfully used to sort different cell cycle stages under high-throughput. We expect the proposed ACBH probe to provide comprehensive information for the analysis of trace DNA in mitochondria and guide the early diagnosis of mitochondria-related genetic diseases.

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