摘要： A new ratiometric ?uorescence probe is constructed for the detection of rifampin (RIF). Amino-modi?ed silicon nanoparticles (SiNPs) and mercaptoundecanoic acid capped gold nanoclusters (MUA-AuNCs) are self-assembled into nanocomposites, showing dual ?uorescence emissions, respectively, at 440 and 615 nm under a single excitation of 300 nm. The morphology, surface chemistry and optical properties of the nanocomposites are ?nely investigated through transmission electron microscopy (TEM), Fourier transforms infrared spectroscopy (FT-IR), UV–vis absorbance, dynamic and steady state ?uorescence spectroscopy. Owning to rich hydroxyl groups, RIF can bind with MUA-AuNCs though hydrogen bonds resulting in the red ?uorescence quenching. But the SiNPs keep their own blue ?uorescence stable, which can act as an internal reference for ratiometric detection. By means of the ratio I615/I440, the linear relationship is established in the range from 0.1 to 5 μM with the detection limit of 0.04 μM. In addition, the synchronous and asynchronous ?uorescence 2D correlation maps have been created to in-depth study the relative detecting mechanism.