Multifunctional plasmonic gold nanoisland films for enhanced cell theranostics through photothermal therapy and surface-enhanced Raman scattering detection

Plasmonic gold nanomaterials have numerous applications in biomedical therapy and sensing. In this work, plasmonic gold nanoisland films (AuNIFs) were demonstrated to have significant applications in photothermal therapy and surface-enhanced Raman scattering (SERS) detection.
A seed-mediated growth method was used to fabricate AuNIFs on glass substrates. Material Characterizations confirmed the successful preparation of AuNIFs.
Surface plasmon resonance produced a broad UV-Vis absorption spectrum (400–1000 nm). Under 808-nm near-infrared (NIR) laser irradiation (1.5 mW/cm2), AuNIFs reached 65°C, generating sufficient heat to kill Vero epithelial cells. The cell death rate of Vero cells under laser irradiation was estimated to be 1.38 times higher than that in the absence of laser irradiation. The AuNIFs exhibited stable photothermal performance under cyclic laser exposure for 10 min and outperformed conventional photothermal therapy in eradicating Vero cells. Compared to bare glass slides, AuNIFs promoted more-confluent Vero cell growth. Additionally, the AuNIF platform enhanced the Raman signal of Vero cells according to a SERS analysis. Fluorescence imaging confirmed laser-induced cell death, as indicated by green fluorescence.
By integrating photothermal therapy and SERS detection, AuNIFs demonstrated strong potential as multifunctional substrates for cell theranostics.

等离子体金纳米材料在生物医学治疗与传感领域拥有诸多应用。本研究中，等离子体金纳米岛薄膜（AuNIFs）被证实可有效应用于光热治疗与表面增强拉曼散射（SERS）检测领域。
研究采用晶种介导生长法在玻璃基底上制备AuNIFs，材料表征结果证实了AuNIFs的成功制备。
其表面等离子体共振效应可产生宽波段紫外-可见（UV-Vis）吸收光谱（400~1000 nm）。在808 nm近红外（NIR）激光辐照（功率密度1.5 mW/cm²）条件下，AuNIFs的温度可升至65℃，产生足以杀死Vero上皮细胞的热量。经估算，激光辐照下Vero细胞的死亡率较无激光辐照组高出1.38倍。AuNIFs在10分钟循环激光辐照下表现出稳定的光热性能，且在清除Vero细胞方面优于传统光热治疗手段。与裸玻片相比，AuNIFs可促进Vero细胞形成更致密的融合单层。此外，SERS分析结果显示，AuNIF平台可增强Vero细胞的拉曼信号；荧光成像结果证实了激光诱导的细胞死亡，绿色荧光即为该现象的表征。
通过整合光热治疗与SERS检测，AuNIFs展现出作为细胞治疗诊断多功能基底的巨大应用潜力。