[Preparation and characterization of morin-modified self-assembled multilayer films of gold nanoparticles]

Quartz substrate was modified with self-assembled monolayer of gamma-aminopropyl-triethylsilane by aqueous phase silanization, giving an homogenous surface terminated with amino groups. Colloidal gold nanoparticles were further assembled on this functionalized monolayer substrate, forming a gold nanoparticles/APES/quartz nanocomposite structure. Flourescent reagent morin was assembled onto the self-assembled multilayer films of gold nanoparticles via DL-cystenine (Cys) intermediate. The morin-modified self-assembled multilayer films of gold nanoparticles could detect triphenyltin fluorimetrically with high sensitivity, and the detection limit was as low as 1.297 x 10(-8) mol x L(-1). The effects of various factors such as concentration of solution, pH, and assembling time were investigated. The response mechanism behind caused the enhancement of relative fluorescence intensity was also discussed.