NanoPhotonics Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, U.K.
ACS Sens. 2023 Jul 28;8(7):2879-2888. doi: 10.1021/acssensors.3c00967. Epub 2023 Jul 6.
We demonstrate the reliable creation of multiple layers of Au nanoparticles in random close-packed arrays with sub-nm gaps as a sensitive surface-enhanced Raman scattering substrate. Using oxygen plasma etching, all the original molecules creating the nanogaps can be removed and replaced with scaffolding ligands that deliver extremely consistent gap sizes below 1 nm. This allows precision tailoring of the chemical environment of the nanogaps which is crucial for practical Raman sensing applications. Because the resulting aggregate layers are easily accessible from opposite sides by fluids and by light, high-performance fluidic sensing cells are enabled. The ability to cyclically clean off analytes and reuse these films is shown, exemplified by sensing of toluene, volatile organic compounds, and paracetamol, among others.
我们展示了一种可靠的方法，可以在具有亚纳米间隙的随机密堆积阵列中创建多层金纳米粒子，作为敏感的表面增强拉曼散射基底。使用氧等离子体刻蚀，可以去除所有产生纳米间隙的原始分子，并替换为提供低于 1nm 极一致间隙尺寸的支架配体。这允许对纳米间隙的化学环境进行精确调整，这对于实际的拉曼传感应用至关重要。由于流体和光可以从相对的两侧轻松到达所得的聚集层，因此可以实现高性能的流体传感单元。可以通过循环清洗分析物并重复使用这些薄膜来证明这一点，例如对甲苯、挥发性有机化合物和扑热息痛等的传感。
