AgNPs uniformly doped onto Polyvinyl alcohol microspheres for optical recognition application

Via surface aldolisation or semi-aldolisation, the surface of poly(vinyl alcohol) (PVA) microspheres was uniformly doped with sliver nanoparticles (AgNPs). Scanning electron microscope (SEM) revealed the spherical shape of the AgNPs@PVA microspheres. Fourier transform infrared spectra and X-ray photoelectron spectra (XPS) provided information on the surface interactions between AgNPs and PVA microspheres. The AgNPs@PVA microspheres offered simple and rapid qualitative detection of Hg2+ ions and pH values through a colour change in aqueous solution. The AgNPs@PVA microspheres also showed off–on behaviour.