CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China , Hefei 230026, China.
Environ Sci Technol. 2017 Dec 19;51(24):14092-14099. doi: 10.1021/acs.est.7b04430. Epub 2017 Dec 1.
Dissolved organic matter (DOM) is ubiquitous in aqueous environments and plays a significant role in pollutant mitigation, transformation and organic geochemical circulation. DOM is also capable of forming carcinogenic byproducts in the disinfection treatment processes of drinking water. Thus, efficient methods for DOM quantification are highly desired. In this work, a novel sensor for rapid and selective detection of humic substances (HS), a key component of DOM, based on fluorescence quenching of nitrogen-doped carbon quantum dots was developed. The experimental results show that the HS detection range could be broadened to 100 mg/L with a detection limit of 0.2 mg/L. Moreover, the detection was effective within a wide pH range of 3.0 to 12.0, and the interferences of ions on the HS measurement were negligible. A good detection result for real surface water samples further validated the feasibility of the developed detection method. Furthermore, a nonradiation electron transfer mechanism for quenching the nitrogen-doped carbon-dots fluorescence by HS was elucidated. In addition, we prepared a test paper and proved its effectiveness. This work provides a new efficient method for the HS quantification than the frequently used modified Lowry method in terms of sensitivity and detection range.
溶解有机质（DOM）在水环境中普遍存在，在污染物的缓解、转化和有机地球化学循环中起着重要作用。DOM 还能够在饮用水的消毒处理过程中形成致癌副产物。因此，人们非常希望开发出高效的 DOM 定量方法。在这项工作中，我们基于氮掺杂碳量子点的荧光猝灭，开发了一种用于快速、选择性检测富里酸（HS）的新型传感器，HS 是 DOM 的关键组成部分。实验结果表明，HS 的检测范围可以扩展到 100mg/L，检测限为 0.2mg/L。此外，检测在 3.0 到 12.0 的宽 pH 范围内有效，离子对 HS 测量的干扰可以忽略不计。对实际地表水样品的良好检测结果进一步验证了所开发检测方法的可行性。此外，还阐明了 HS 通过猝灭氮掺杂碳量子点荧光的非辐射电子转移机制。此外，我们还制备了一种试纸，并证明了其有效性。与常用的改良 Lowry 法相比，该方法在灵敏度和检测范围方面为 HS 的定量提供了一种新的有效方法。
