State Key Laboratory of Oncogenes and Related Genes, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
Shenzhen Research Institute of Xiamen University, Shenzhen 518000, China.
J Phys Chem Lett. 2022 Jul 21;13(28):6496-6502. doi: 10.1021/acs.jpclett.2c01741. Epub 2022 Jul 12.
Self-assembled monolayers (SAMs) of thiols on plasmonic nanoparticles constitute one of the most common methods for fabricating surface-enhanced Raman scattering (SERS) nanoprobes with wide applications. However, this method greatly limits the sufficient utilization of electromagnetic fields derived from plasmon excitation of the nanoparticles, because the thickness of SAMs (<1 nm) is usually much smaller than the attenuation length (>10 nm) of the fields. To overcome this, we propose a three-dimensional (3D) volume-active SERS (VASERS) technique to break the SAM limit, which integrates large amounts of thiol reporters into polydopamine shells on silver nanoparticles via Michael addition and allows sufficient utilization of 3D electromagnetic fields, leading to a dramatic increase in the intensity of the signal of the nanoprobes by about one order of magnitude. We demonstrate the universality of this strategy on various thiol reporters and plasmonic substrates. We also show that orthogonal VASERS nanoprobes with alkyne readout allow for high-precision tumor targeting and margin delineation.
自组装单分子层（SAMs）的硫醇在等离子体纳米粒子上构成了制造表面增强拉曼散射（SERS）纳米探针的最常见方法之一，具有广泛的应用。然而，这种方法极大地限制了从纳米粒子的等离子体激发中获得的电磁场的充分利用，因为 SAMs 的厚度（<1nm）通常比场的衰减长度（>10nm）小得多。为了克服这一问题，我们提出了一种三维（3D）体积活性 SERS（VASERS）技术来打破 SAM 限制，该技术通过迈克尔加成将大量硫醇报告分子整合到银纳米粒子的聚多巴胺壳中，并允许充分利用 3D 电磁场，从而使纳米探针信号的强度显著增加约一个数量级。我们在各种硫醇报告分子和等离子体基底上证明了这种策略的通用性。我们还表明，带有炔烃读出功能的正交 VASERS 纳米探针可以实现高精度的肿瘤靶向和边缘描绘。
