A nanocomposite optosensor of lead ions in water

Spectral dependences of complexation in the system of the xylenol orange dye that was immobilized on the surface of ZnO nanoparticles introduced into the volume of hydrogel and lead ions Pb$^{2+}$ have been investigated. It has been shown that the deposition of the dye on the ZnO nanoparticles leads to its binding on the surface and absence of its washing out from the hydrogel, but this process does not prevent the formation of the complexes of the dye with lead ions, which is characterized by increased absorption in the region of 580 nm. The film nanocomposite can be used as a sensor due to its high sensitivity to the presence of low lead concentrations.