二元混合表面活性剂用于窄吸收金纳米棒的无种子合成

Seedless Synthesis of Gold Nanorods with Narrow Absorption Using Binary Surfactant Mixture

利用十六烷基三甲基溴化铵(CTAB)和油酸钠(NaOL)二元混合表面活性剂体系,开发了一种高质量金纳米棒(AuNRs)的无种子合成方法.通过透射电子显微镜(TEM)、紫外-可见-近红外吸收光谱(UV-Vis-NIR)和热成像仪对金纳米棒的形貌、光学性质及光热性能进行了表征.实验结果表明,当NaOL浓度为8.21~11.5 mmol/L时,能够获得形貌均匀的AuNRs,其纵向表面等离子体共振吸收(LSPR)在650~1150 nm范围内可调.该方法制得的样品具有较窄的LSPR半峰宽,特别是在制备LSPR在近红外二区(NIR-II,大于1000 nm)的AuNRs方面具有明显优势.在1064 nm激光的辐照下,金纳米棒溶液能够快速升温至67℃,光热转换效率可达31.5%,同时表现出优秀的光热稳定性,在近红外二区光声成像和光热治疗方面具有良好的应用价值.

A seedless synthetic method was developed for the preparation of high-quality gold nanorods(AuNRs)using binary surfactant mixture containing hexadecyltrimethylammonium bromide(CTAB)and sodium oleate(NaOL).The morphologies,optical properties and photothermal performances were characterized by means of transmission electron microscopy(TEM),UV-Vis-NIR spectroscopy and infrared thermal imaging system.The results indicate that uniform AuNRs can be obtained with a NaOL concentration between 8.21—11.5 mmol/L,and their longitudinal surface plasmon resonance(LSPR)wavelength can be tuned from 650 nm to 1150 nm.The AuNRs prepared with this method exhibited narrow LSPR peak,especially in the second near infrared-Ⅱregion(NIR-Ⅱ,λ>1000 nm).Under the irradiation of 1064 nm laser,the temperature of AuNRs solution can increase to 67℃,with a photothermal conversion efficiency of 31.5%.The AuNRs also exhibited excellent photothermal stability under laser irradiation,which can be useful for photoacoustic imaging and photothermal therapy in the second near-infrared region.