Heteroatom-doped carbon dots (CDs) with a high photoluminescent quantum yield (PLQY) have recently attracted attention due to their applications in chemical sensors, photocatalysis, bioimaging, and drug delivery. Nitrogen and phosphorus are in close proximity to carbon in the periodic table and are key tracking elements in the field of biomedical imaging. These two elements alter the optical and electronic properties of CDs and help improve the fundamental understanding of their PLQY. This can also lead to multifunctional usage in photoimaging and photothermal therapy. However, most PLQYs resulting from the synthesis of P-doped CDs are currently below 50%. These CDs have limited usefulness in the fields of bioimaging and drug delivery. In this study, a single-step, high-efficiency hydrothermal method was applied to synthesize nitrogen and phosphorous-doped carbon dots ((N,P)-CDs) with a PLQY of up to 53.8% with independent emission behavior. Moreover, the CDs presented high monodispersity, robust excitation-independent luminescence, and stability over a large pH range. Spectroscopic investigations indicated that the PLQY of the (N,P)-CDs was primarily due to the addition of P and the passivation effect of the oxidized surface. The excellent fluorescence properties of (N,P)-CDs can be effectively and selectively quenched by Hg²⁺ ions. Such systems show a linear response in the 0–900 nM concentration range with a short response time, indicating their potential for applications in the fields of chemistry and biology.

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具有高光致发光量子产率（PLQY）的杂原子掺杂碳点（CDs）由于其在化学传感器，光催化，生物成像和药物输送中的应用而引起了人们的关注。氮和磷在元素周期表中与碳非常接近，是生物医学成像领域中的关键跟踪元素。这两个元素改变了CD的光学和电子特性，有助于提高对PLQY的基本了解。这也可以导致在光成像和光热疗法中的多功能使用。但是，目前大多数由P掺杂CD合成产生的PLQY都低于50％。这些CD在生物成像和药物输送领域的用途有限。在这项研究中，只需一步，采用高效水热法合成了具有独立发射行为的PLQY高达53.8％的氮和磷掺杂碳点（（N，P）-CDs）。此外，CD表现出高的单分散性，鲁棒的激发独立发光以及在较大pH范围内的稳定性。光谱研究表明，（N，P）-CDs的PLQY主要归因于P的添加和氧化表面的钝化作用。（N，P）-CDs的优异荧光性质可以通过Hg有效和选择性地猝灭 光谱研究表明，（N，P）-CDs的PLQY主要归因于P的添加和氧化表面的钝化作用。（N，P）-CDs的优异荧光性质可以通过Hg有效和选择性地猝灭 光谱研究表明，（N，P）-CD的PLQY主要是由于P的添加和氧化表面的钝化作用所致。（N，P）-CDs的优异荧光性质可以通过Hg有效和选择性地猝灭²⁺离子。这样的系统在0-900 nM浓度范围内显示线性响应，响应时间短，表明它们在化学和生物学领域的应用潜力。

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