There has been growing interest in recent years in developing multifunctional materials for studying the structure interface in biological systems. In this regard, the multimodal systems, which possess activity in the near-infrared (NIR) region, become even more critical for the possibility of improving examined biotissue depth and, eventually, data analysis. Herein, we engineered bi-modal contrast agents by integrating carbon nanotubes (CNT) and gold nanoparticles (AuNP) around silica microspheres using the Layer-by-Layer self-assembly method. The experimental studies revealed that microspheres with CNT sandwiched between AuNP exhibit strong absorption in the visible and NIR regions and high optoacoustic contrast (OA, also called photoacoustics) and Raman scattering when illuminated with 532 nm and 785 nm lasers, respectively. The developed microspheres demonstrated amplification of the signal in the OA flow cytometry at the laser wavelength of 1064 nm. This finding was further validated with ex vivo brain tissue using a portable Raman spectrometer and imaging with the Raster-scanning OA mesoscopy technique. The obtained data suggest that the developed contrast agents can be promising in applications of localization OA tomography (LOT), OA flow cytometry, and multiplex SERS detection.

近年来，人们对开发用于研究生物系统结构界面的多功能材料越来越感兴趣。在这方面，在近红外 (NIR) 区域具有活性的多模式系统对于提高检查的生物组织深度和最终数据分析的可能性变得更加关键。在这里，我们通过使用逐层自组装方法在二氧化硅微球周围集成碳纳米管 (CNT) 和金纳米颗粒 (AuNP) 来设计双峰造影剂。实验研究表明，将 CNT 夹在 AuNP 之间的微球在分别用 532 nm 和 785 nm 激光照射时，在可见光和近红外区域表现出强烈的吸收，以及高光声对比度（OA，也称为光声学）和拉曼散射。开发的微球在 1064 nm 激光波长下显示了 OA 流式细胞仪中的信号放大。这一发现得到了进一步验证使用便携式拉曼光谱仪和光栅扫描 OA 介观技术成像的离体脑组织。获得的数据表明，开发的造影剂在定位 OA 断层扫描 (LOT)、OA 流式细胞术和多重 SERS 检测中的应用前景广阔。