Self-assembled deposition of Ag nano-particles on PPy@PEDOT:PSS films to detect melamine molecules

We studied a Surface-enhanced Raman scattering (SERs) film by self-assembled deposition of Ag nanoparticles on the surface of PPy@PEDOT:PSS films to detect melamine molecules. The PPy@PEDOT:PSS film was prepared using an electrochemical polymerization method in a mixture solution of PPy and PEDOT:PSS. Then, Ag nanoparticles were directly deposited on the surface of PPy@PEDOT:PSS films by a chemical self-assembly method as an active SERs substrate to detect melamine molecules. The results showed that the density of Ag nanoparticles on the surface of PPy@PEDOT:PSS film was gradually increased due to the increase of depositional time of Ag nanoparticles. Accordingly, The SERs effect was also substantially enhanced. The signal of melamine was increased up to 440 times. The melamine molecules at 6.4 ng/ml concentration could be clearly identified. This preparing method of SERs film and detecting method of melamine molecules provide a new strategy for the design and application of chemical sensors and bio-sensors.