载金纳米棒温度刺激响应性杂化微凝胶的制备及在SERS基底中的应用

Preparation of Au Nanorod Loading Temperature Stimulus Responsiveness Hybrid Microgel and Its Application as SERS Substrate

首先采用种子生长法合成了形状规整的金纳米棒(AuNRs),再采用3-丁烯酸对AuNRs表面进行改性,最后通过种子沉淀聚合法将聚(N-异丙基丙烯酰胺)(PNIPAM)包覆在AuNRs表面,制备了以AuNR为核、交联的PNIPAM为壳层的核壳结构型温度刺激响应性杂化微凝胶。以此杂化微凝胶作为表面增强拉曼光谱(SERS)的基底,升高温度使杂化微凝胶发生体积相转变,能检测到以常规纳米金属材料为基底难以检测的1-萘酚(1-NOH)水溶液的SERS信号。并且,随着温度从5℃升高到55℃,1-NOH的SERS信号逐渐增强。这是由于杂化微凝胶发生温度变化刺激的体积相转变过程中,可捕捉水溶液中溶解的微量1-NOH,使其富集在杂化微凝胶内部。

The gold nanorods(AuNRs) were firstly synthesized by seed growth method,and monodisperse temperature responsive hybrid nanogels with well-defined core-shell structure based on AuNRs as core and crosslinked poly(Nisopropylacrylamide)(PNIPAM) as shell were fabricated by seed-precipitation polymerization secondly. Using AuNR@ PNIPAM microgels as substrates,the surface enhanced Raman spectroscopy(SERS) signal of the aqueous solution of 1-naphthol can be detected by raising temperature to make the hybrid microgels undergo volume phase transition,which cannot be detected by SERS using conventional metal nanomaterials as substrates. This is due to the fact that the hybrid microgels can catch trace 1-naphthol in the aqueous solution during their temperature change triggered volume phase transition.