Structural and optical properties of chitosan–poly(amidoamine) dendrimer composite thin film for potential sensing Pb2+ using an optical spectroscopy

Poly(amidoamine) and chitosan have received attention due to their potential for sensing application. Chitosan–poly(amidoamine) dendrimer composite (Cs–PAMAM) thin film have been prepared using a spin coating technique. The functional group of Cs–PAMAM has been investigated using Fourier transform infrared spectroscopy (FTIR). The UV–vis absorption of Cs–PAMAM thin film was high with the optical band gap of 4.09 eV. The studies of potential sensing of the Cs–PAMAM thin film gave positive responses towards Pb2+ ion by using surface plasmon resonance spectroscopy. The surface morphology of the Cs–PAMAM composite thin film was observed using atomic force microscopy (AFM) and confirmed the interaction of Pb2+.