Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, International Joint Research Center for Photoresponsive Molecules and Materials, School of Chemical & Material Engineering, Jiangnan University, Wuxi, 214122, P. R. China.
Nanoscale. 2018 Nov 29;10(46):21809-21817. doi: 10.1039/c8nr07445c.
Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ∼15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15-85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
基于荧光的纳米温度计具有通过非接触式方法提供温度测量准确性的潜力。在此，通过两种带有相反电荷的荧光 CD 的静电自组装，制备了基于 C 点/C 点的双发射温度传感平台。该双发射平台由几个具有两个发射中心的近球形 CD 组成，分别位于蓝色（440nm）和橙色（590nm）区域。橙色荧光在约 15 至 85°C 的范围内对外界温度表现出明显的响应；另一方面，蓝色荧光几乎保持不变。通过肉眼可以清楚地观察到，由于温度的变化，荧光颜色从橙色到蓝色发生连续变化。因此，所制备的基于 C 点的双发射纳米球可用于具有高重现性和灵敏度（0.93%/°C）的光学测温。详细的特性研究表明，温度（在 15-85°C 窗口内）会影响橙色发射 CD 的表面状态，而蓝色发射 CD 不受影响。提出了一个模型来解释这些观察结果。最后，利用其出色的生物相容性和稳定性，成功地将基于 CD 的荧光纳米温度计用于细胞内温度变化的可视化测量。
