摘要

The enzymatic cleavage of DNA by nucleases is the origin of many biological processes including genetic engineering, and monitoring sensitively the enzymatic cleavage of DNA is of great significance for life science. Herein, a new CL strategy has been developed for the sensitive, convenient and direct monitoring of the cleavage of ssDNA by specific S1 nuclease based on quite different CL response of (+)AuNPs to long ssDNA and fragmented DNA generated from the enzymatic cleavage reaction of DNA. Strong signal amplification of (+)AuNPs and the thorough and effective hydrolysis reaction of ssDNA render this method to exert remarkable assay performance for detection of S1 nuclease activity with high sensitivity (the detection limit was as low as 6.5 x 10(-9) U/mu L) and wide linear response range from 0.02 x 10(-6) U/mu L to 2 x 10(-6) U/mu L. Together with homogeneous analysis format of "incubate-and-monitor" in the strategy and the simple and easy preparation of signal indicator used for the assay, the present CL assay for probing the enzymatic cleavage process of ssDNA and detecting S1 nuclease activity has displayed convenient operability with low cost. Such excellent feature implied the potential application for monitoring DNA cleavage and facile and sensitive detection of nuclease activity. What is more, based on the inhibition of enzymatic cleavage of DNA, it also provides a promising candidate technique for drug screening and discovery in clinical diagnostics.