Qin Chengbing, Zhang Xiaorong, He Wenjun, Zhang Guofeng, Chen Ruiyun, Gao Yan, Xiao Liantuan, Jia Suotang
Opt Express. 2019 Feb 4;27(3):2886-2898. doi: 10.1364/OE.27.002886.
Photoluminescence (PL) of Au nanoparticles is appealing for various biological applications, owing to their unique advantages. However, widespread applications are still limited by their extremely low quantum yield. Here, we report on the giant PL enhancement of aggregated Au nanospheres by continuous-wave (CW) laser irradiation. Our studies show that the laser-induced PL enhancement is influenced by the wavelength and power density of irradiation laser, as well as the size of Au nanospheres. The averaged intensity of Au nanospheres after irradiation by 405 nm CW laser at power density of 6 MW/cm is 75 times that of the as-prepared sample, where the highest enhancement of 150 folds is obtained. The giant PL enhancement is attributed to laser-induced photothermal welding and reshaping of adjacent Au nanospheres, which will dramatically enhance the incidence light field in the crevices around the welding areas by surface plasmon resonance. These studies not only declare that Au nanospheres are expected to find many new applications in PL-based biosensing and bioiamging, but also suggest that CW laser can be used as a versatile tool to weld and reshape the Au nanospheres in order to build up functionalized electronic and optoelectronic devices.
由于其独特优势，金纳米颗粒的光致发光（PL）在各种生物应用中颇具吸引力。然而，其广泛应用仍受限于极低的量子产率。在此，我们报道了连续波（CW）激光辐照使聚集的金纳米球的PL大幅增强。我们的研究表明，激光诱导的PL增强受辐照激光的波长和功率密度以及金纳米球尺寸的影响。在功率密度为6 MW/cm的405 nm连续波激光辐照后，金纳米球的平均强度是制备样品的75倍，其中获得了高达150倍的最高增强。这种巨大的PL增强归因于激光诱导的相邻金纳米球的光热焊接和重塑，这将通过表面等离子体共振显著增强焊接区域周围缝隙中的入射光场。这些研究不仅表明金纳米球有望在基于PL的生物传感和生物成像中找到许多新应用，还表明连续波激光可作为一种通用工具来焊接和重塑金纳米球，以构建功能化的电子和光电器件。
