柠檬酸辅助可控制备花状银粒子及其表面增强拉曼散射性能

以抗坏血酸为还原剂,柠檬酸为结构导向剂,一步还原硝酸银,合成了尺寸和形状可调的花状银颗粒。纳米粒子的粒径可在600～1 200 nm范围内调整,表面突起可达到10～25 nm。柠檬酸的化学性质在银纳米粒子合成多级花状银结构的过程中起着至关重要的作用。通过改变柠檬酸或抗坏血酸溶液的用量,银结构的各向异性形貌可以很容易地调节。以制备的多级花状银颗粒作为表面增强拉曼散射(SERS)基底,对浓度为10~(-10)mol·L~(-1)的罗丹明6G(R6G)仍具有较高的检测灵敏度。

Controlled Fabrication and Surface Enhanced Raman Scattering Performance of Flower-like Silver with Assistance of Citric Acid

Flower-like silver particles with tunable size and shape had been synthesized in one-step by reducing silver nitrate (AgNO₃) with ascorbic acid as reducing agent and citric acid as structure directing agent. The size of nanoparticles could be adjusted from 600 to 1 200 nm, and the surface protrusion could reach 10~25 nm. The chemical nature of citric acid played a vital role in the process of assembling silver nanoparticles into flower-like hierarchical structure. The anisotropic morphologies of as-synthesized silver structures could be readily tuned by varying the dosage of citric acid or ascorbic acid solution. The textured flower-like Ag particles were tested as substrates for the surface enhanced Raman scattering (SERS) and showed high sensitivity for detecting rhodamine 6G (R6G) at a concentration as low as 10^-10 mol·L^-1.