Solvothermal synthesis and formation mechanism of chain-like triangular silver nanoplate assemblies: Application to metal-enhanced fluorescence (MEF)

Novel silver chain-like triangular nanoplate assemblies (CTNAs) were synthesized via a solvothermal approach. The shape of CTNAs was determined by some dominant parameters, including the concentration of poly (vinyl pyrrolidone), reactive time and temperature. Each CTNA is a single crystal with continuous lattice fringes in the inner, and could be considered as the combination of one-dimensional nanobelt and two-dimensional nanoplates. The formation of the CTNAs could be ascribed to the secondary growth of the nanocrystals. The edges of the nanoplates in the assembly were parallel to each other in order to maintain the lower surface energy. Interestingly, this novel nanostructure is a significant improvement for application in metal-enhanced fluorescence. Typical 88- and 13-fold enhancement in the emission intensity of dye Rhodamine B could be respectively achieved on the surface of silver colloids and silver coated-glass. The CTNAs have wide potential applications in the improvement of the sensitivity for medical or biological assays.