Synthesis and anisotropic self-assembly of Ag nanoparticles immobilized by the Pluronic F127 triblock copolymer for colorimetric detection of H2O2

With dopamine as a reducing and sticking agent, triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), Pluronic F127, was employed to immobilize and stabilize silver nanoparticles (Ag NPs) by the chemical reduction of silver nitrate, AgNO3. Thus, a ternary system comprising Ag NPs, dopamine and F127, i.e. a Ag@DA@F127 system was constructed. In this ternary system, Ag NPs were anisotropically self-assembled and uniformly dispersed in network-like F127 micelles. As evidenced the dispersion stability of Ag NPs in this system was significantly enhanced compared to the Ag@DA and Ag@NaBH4@F127 system, which in turn resulted in a more sensitive and quantitative detection of H2O2. Further investigation demonstrated that the Ag@DA@F127 system exhibited a UV-vis absorption band at similar to 405 nm and the intensity of this absorption band dramatically decreased linearly over the concentration range of 0.1-100 mu M H2O2 (r(2) = 0.99056), deriving a detection limit of 33 nM, which was superior to recent reports. Apart from its excellent performance in H2O2 detection, this Ag@DA@F127 system has other benefits including facile and simple, being environmentally friendly, and especially the formation of a specific network-like structure to fully disperse Ag NPs, which makes it practical in H2O2 detection.