▎ 摘　　要

A convenient to prepare GO/CS/Ag2S nanocomposite film was successfully developed by in situ grown methods. The resultant heterostructures were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy and differential scanning calorimetry. A hybrid probe of GO/CS/Ag2S nanocomposite film for detecting toluene using FRET technique is demonstrated through the fluorescence. The conformation of chitosan changes from the state of the extension to the state of the contraction by adding toluene to change the polarity of solvent, which decreases the distance between Ag2S and GO, enhancing the quenching effect between them. The fluorescence results reveal that the GO/CS/Ag2S nanocomposite film is sensitive to toluene. Notably, the fluorescence intensity of the composite film is quantitatively and reversibly controlled by toluene from 0 to 1.6 x 10(-2) mol/L.