One-Step Controlled Synthesis of Size-Tunable Toroidal Gold Particles for Biochemical Sensing
One-Step Controlled Synthesis of Size-Tunable Toroidal Gold Particles for Biochemical Sensing
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DOI：
10.1021/acsanm.9b01856
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发表时间：
2019-12-01
影响因子：
5.9
通讯作者：
Su, Judith
中科院分区：
文献类型：
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作者：
Phuong-Diem Nguyen;Zhang, Xuanru;Su, Judith
控制纳米粒子的大小和形状是材料科学的主要目标。在这里，我们展示了用十二烷基硫酸钠(SDS)和十六烷基三甲基溴化铵(CTAB)组成的表面活性支架，快速、30分钟、可控地一步合成尺寸从350 nm到1.7微米的金粒子(TAUP)。合成的tAUP具有从环腔向内或向外突出的纳米棒。纳米棒的数量可以通过两步温度变化过程来调节，以产生所谓的粗略tAUP。这种环形金颗粒结构在近红外区显示出表面等离子体消光峰，对4-巯基苯甲酸(4-MBA)分子的检测具有很高的表面增强拉曼散射(SERS)灵敏度。突出的纳米棒显著增强了环形腔内的电磁场振荡。通过对4-MBA分子的灵敏检测以及模拟证实了这一点。粗糙的TAUP结构产生了最高的灵敏度，估计的总增强因子(TE)为3.33×10(6)，比金纳米星的报道大了两个数量级。通过改变十二烷基硫酸钠和十六烷基三甲基溴化铵的浓度比，可以得到各种不同的金结构，如金纳米树枝晶、纳米线和纳米链。TAUPs独特的结构和等离子体性质为超灵敏生化传感提供了可能。
Controlling the size and shape of nanoparticles is a major goal in materials science. Here we show the fast, 30 min, controlled one-step synthesis of gold particles (tAUPs) with sizes tunable from 350 nm to 1.7 mu m by using a mixture of surfactant scaffolds made from sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB). The as-synthesized tAUPs have nanospikes that protrude either inward or outward from the ring cavity. The number of nanospikes can be tuned by a two-step temperature change process to create so-called rough tAUPs. The toroidal gold particle structures exhibit surface plasmon extinction peaks in the near-infrared region and demonstrate a high surface-enhanced Raman scattering (SERS) sensitivity for the detection of 4-mercaptobenzoic acid (4-MBA) molecules. The protruding nanospikes significantly enhance the electromagnetic field oscillating inside the ring cavity. This is confirmed through sensitive detection of 4-MBA molecules as well as by simulation. Rough tAUP structures generate the highest sensitivity with an estimated total enhancement (TE) factor of 3.33 x 10(6), which is 2 orders of magnitude greater than reported by gold nanostars. A variety of different gold structures such as gold nanodendrites, nanowires, and nanochains can be obtained by changing the SDS to CTAB concentration ratios. The unique structures and plasmonic properties of tAUPs hold promise for ultrasensitive biochemical sensing.