论文标题
向上转换显微镜的发光二极管激发：定量评估
Light-emitting diode excitation for upconversion microscopy: a quantitative assessment
论文作者
论文摘要
基于灯笼的上转换纳米颗粒（UCNP）通常需要高功率激励激发。在这里，我们报告使用970 nm发光二极管（LED）的不连贯的激发在单纳米颗粒敏感性下的广阔场上上转换显微镜（LED）。我们表明，由于其广泛的发射光谱，LED激发对UCNP的有效性降低了3倍，并且与激光照明相比产生高背景。为此，我们使用时间门控发光检测来消除LED源的残留背景，以便在1.18 W CM-2的LED激发下清楚地鉴定出具有高敏化剂（YB3+）掺杂和惰性壳保护的单个UCNP，如由相关的电子显微镜图像所证实。亲水性UCNP通过多糖涂层通过易于的配体交换方案获得，以证明使用LED激发对细胞摄取的成像。这些结果表明，一种可行的方法，可以绕过将UCNP和上转换显微镜应用于生命科学研究时与高功率激光器相关的局限性。
Lanthanide-based upconversion nanoparticles (UCNPs) generally require high power laser excitation. Here we report wide-field upconversion microscopy at single-nanoparticle sensitivity using incoherent excitation of a 970-nm light-emitting diode (LED). We show that due to its broad emission spectrum, LED excitation is about 3 times less effective for UCNPs and generates high background compared to laser illumination. To counter this, we use time-gated luminescence detection to eliminate the residual background from the LED source, so that individual UCNPs with high sensitizer (Yb3+) doping and inert shell protection become clearly identified under LED excitation at 1.18 W cm-2, as confirmed by correlated electron microscopy images. Hydrophilic UCNPs are obtained by polysaccharide coating via a facile ligand exchange protocol to demonstrate imaging of cellular uptake using LED excitation. These results suggest a viable approach to bypassing the limitations associated with high-power lasers when applying UCNPs and upconversion microscopy to life science research.
