Highly sensitive non-contact mode temperature sensing is substantial for studying fundamental chemical reactions, biological processes, and applications in medical diagnostics. Nanoscale-based thermometers are guaranteeing non-invasive probes for sensitive and precise temperature sensing with subcellular resolution. Fluorescence-based temperature sensors have shown great capacity since they operate as “non-contact” mode and offer the dual functions of cellular imaging and sensing the temperature at the molecular level. Advancements in nanomaterials and nanotechnology have led to the development of novel sensors, such as nanothermometers (novel temperature-sensing materials with a high spatial resolution at the nanoscale). Such nanothermometers have been developed using different platforms such as fluorescent proteins, organic compounds, metal nanoparticles, rare-earth-doped nanoparticles, and semiconductor quantum dots. Carbon dots (CDs) have attracted interest in many research fields because of outstanding properties such as strong fluorescence, photobleaching resistance, chemical stability, low-cost precursors, low toxicity, and biocompatibility. Recent reports showed the thermal-sensing behavior of some CDs that make them an alternative to other nanomaterials-based thermometers. This kind of luminescent-based thermometer is promising for nanocavity temperature sensing and thermal mapping to grasp a better understanding of biological processes. With CDs still in its early stages as nanoscale-based material for thermal sensing, in this review, we provide a comprehensive understanding of this novel nanothermometer, methods of functionalization to enhance thermal sensitivity and resolution, and mechanism of the thermal sensing behavior.

高灵敏度非接触式温度传感对于研究基本化学反应、生物过程和医学诊断应用具有重要意义。基于纳米级的温度计保证了非侵入式探针能够以亚细胞分辨率实现灵敏、精确的温度传感。基于荧光的温度传感器显示出巨大的能力，因为它们以“非接触”模式运行，并提供细胞成像和分子水平温度传感的双重功能。纳米材料和纳米技术的进步促进了新型传感器的发展，例如纳米温度计（在纳米尺度上具有高空间分辨率的新型温度传感材料）。这种纳米温度计是使用不同的平台开发的，例如荧光蛋白、有机化合物、金属纳米颗粒、稀土掺杂纳米颗粒和半导体量子点。碳点（CD）因其强荧光、抗光漂白、化学稳定性、低成本前体、低毒性和生物相容性等突出特性而引起了许多研究领域的兴趣。最近的报告显示了一些 CD 的热传感行为，使其成为其他基于纳米材料的温度计的替代品。这种基于发光的温度计有望用于纳米腔温度传感和热图绘制，以更好地理解生物过程。由于 CD 作为用于热传感的纳米级材料仍处于早期阶段，在这篇综述中，我们全面了解了这种新型纳米温度计、增强热灵敏度和分辨率的功能化方法以及热传感行为的机制。