Abstract：
Noncontact optical nanothermometers operating within the biological transparency windows are required to study temperature-sensitive biological phenomena at the nanoscale. Nanoparticles containing rare-earth ions such as Nd3+ have been reported to be efficient luminescence-based ratiometric thermometers, however often limited by poor water solubility and concentration-related quenching effects. Herein, we introduce a new type of nanothermometer, obtained by employing low-dimensional carbon nanodots (CNDs) as matrices to host Nd3+ ions (NdCNDs). By means of a one-pot procedure, small (∼7-12 nm), water-soluble nanoparticles were obtained, with high (15 wt %) Nd3+ loading. This stable metal-CND system features temperature-dependent photoluminescence in the second biological window (BW II) upon irradiation at 808 nm, thereby allowing accurate and reversible (heating/cooling) temperature measurements with good sensitivity and thermal resolution. The system possesses remarkable biocompatibility in vitro and promising performance at a high penetration depth in tissue models.
摘要：
需要在生物透明窗口内操作的非接触式光学纳米温度计来研究纳米级的温度敏感生物学现象。据报道，含有Nd3等稀土离子的纳米颗粒是有效的基于发光的比率温度计，然而，通常受到水溶性差和浓度相关的猝灭效应的限制。在这里，我们推出了一种新型的纳米温度计，通过使用低维碳纳米点（CND）作为基质来承载Nd3离子（NdCND）而获得。通过一锅法，小（〜7-12nm），获得水溶性纳米颗粒，具有高(15重量%)Nd3+负载。这种稳定的金属-CND系统在808nm照射时，在第二个生物窗口（BWII）中具有温度依赖性光致发光，从而允许准确和可逆的（加热/冷却）温度测量具有良好的灵敏度和热分辨率。该系统在体外具有显着的生物相容性，并且在组织模型中具有高穿透深度的良好性能。
