Surface Physics Laboratory (National key laboratory), Department of Physics, Fudan University, Shanghai, China.
J Microsc. 2010 Feb;237(2):200-7. doi: 10.1111/j.1365-2818.2009.03324.x.
Two-photon fluorescence microscopy and confocal reflectance microscopy were compared to detect intracellular gold nanorods in rat basophilic leukaemia cells. The two-photon photoluminescence images of gold nanorods were acquired by an 800 nm fs laser with the power of milliwatts. The advantages of the obtained two-photon photoluminescence images are high spatial resolution and reduced background. However, a remarkable photothermal effect on cells was seen after 30 times continuous scanning of the femto-second laser, potentially affecting the subcellular localization pattern of the nanorods. In the case of confocal reflectance microscopy the images of gold nanorods can be obtained with the power of light source as low as microwatts, thus avoiding the photothermal effect, but the resolution of such images is reduced. We have noted that confocal reflectance images of cellular gold nanorods achieved with 50 microW 800 nm fs have a relatively poor resolution, whereas the 50 microW 488 nm CW laser can acquire reasonably satisfactory 3D reflectance images with improved resolution because of its shorter wavelength. Therefore, confocal reflectance microscopy may also be a suitable means to image intracellular gold nanorods with the advantage of reduced photothermal effect.
对比了双光子荧光显微镜和共聚焦反射显微镜，以检测大鼠嗜碱性白血病细胞内的金纳米棒。使用功率为毫瓦特的 800nmfs 激光获得金纳米棒的双光子荧光图像。获得的双光子荧光图像的优点是具有高空间分辨率和减少背景。然而，在飞秒激光连续扫描 30 次后，观察到细胞出现明显的光热效应，可能会影响纳米棒的亚细胞定位模式。在共聚焦反射显微镜的情况下，可以使用低至微瓦特的光源获得金纳米棒的图像，从而避免光热效应，但此类图像的分辨率降低。我们注意到，使用 50μW800nmfs 的共聚焦反射显微镜获得的细胞内金纳米棒的图像分辨率相对较差，而 50μW488nmCW 激光由于其较短的波长，可以获得分辨率提高的合理满意的 3D 反射图像。因此，共聚焦反射显微镜也可能是一种合适的方法，可以通过减少光热效应来成像细胞内的金纳米棒。
