▎ 摘　　要

In the present study, a sensitive platform was constructed to detect gastric cancer marker miR-185 based on graphene oxide (GO) and nuclease DSN. GO can adsorb single-stranded DNA probes and quench its fluorescence. DSN was employed to enhance the sensitivity of the detecting system considering its prominent ability of fluorescence signal amplification effect. Moreover, the method enables to capture miR-185 sensitively in aqueous solution with a detection limit of 476 pM in the range 0-100 nM and R-2 = 0.989. Since miR-185 has been identified as a prognostic biomarker to forecast the course of survival and relapse in gastric cancer (GC), quantitative detection of miR-185 features in developing personalized strategies for GC treatment. In this study, a highly sensitive method for miR-185 detection was rationally designed with the characteristic of fluorescent signal amplification and it was based on constructing graphene oxide sensor and utilizing duplex specific nuclease (DSN). In detail, the cleavage of many DNA signal probes was successfully triggered by the miR-185 target which contributed to the target-recycling mechanism. The protocol exhibited a prominent ability to analyze miR-185 in solution, and it can detect miR-185 at different concentrations as low as 476 pM with a linear range of 0-50 nM. Moreover, this method has gained its prominence in distinguishing the target miRNA from various sequences with one to three base mismatches or other miRNAs. Taken together, it presented the prominent potential to be a candidate tool in the field of clinical diagnosis considering its precise and efficient ability to detect miR-185.