A molecular beacons (MBs) loaded on molybdenum disulfide (MoS2) nanosheets as fluorescence probes for sensitive and versatile detection of microRNAs (miRNAs) through hybridization chain reaction (HCR) has been designed. MoS2 was used as a adsorbent to capture the MBs and a selective fluorescence quencher to reduce the background signal. In the absence of miRNAs, HCR could not be triggered due to the stability of MB probes. The probes attached to the MoS2 surface, efficiently quenching fluorescence of the G-quadruplex/Thioflavin T. However, the presence of target miRNAs triggers the HCR process...