Effect of GO/CS/PbS nanocomposite films on tetraethyoxysilane sensing

Abstract

In this work, a new method for generating highly fluorescent graphene oxide (GO)/chitosan (CS)/PbS nanocomposite films in a mild environment was developed via electrostatic interactions and in situ growth methods. The growth of PbS nanoparticles was initiated by ion complexation with –NH₂ in the CS chain, followed by the thioacetamide treatment of S²⁻ obtained from decomposed samples. Moreover, the distinct features of the nanocomposite films were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, UV–vis, and scanning electron microscopy. Polymer molecules could control nucleation and PbS growth on the surface of GO/CS films to stabilize nanoparticles. The fluorescence spectral measurements clearly showed that the fluorescence of the nanocomposite film was gradually enhanced with tetraethyoxysilane addition. This enhancement was ascribed to the gradual decrease in solvent polarity. Moreover, the CS conformation changed in an extension state, which increased the distance between PbS and GO and reduced their quenching effect. The fluorescence results revealed that the GO/CS/PbS nanocomposite films were sensitive to tetraethoxysilane and could easily be recovered and reused for sensing. Therefore, the nanocomposite films may be specific sensor materials for tetraethoxysilane. Such a simple and efficient strategy would provide an opportunity for the large-scale production of various heterostructures with wide potential applications in the sensing field.