10.1021/acs.est.7b04430.s001 Yan-Fang Guan Yan-Fang Guan Bao-Cheng Huang Bao-Cheng Huang Chen Qian Chen Qian Han-Qing Yu Han-Qing Yu Quantification of Humic Substances in Natural Water Using Nitrogen-Doped Carbon Dots American Chemical Society 2017 pollutant mitigation results show DOM quantification test paper detection limit pH range nonradiation electron transfer mechanism detection method Nitrogen-Doped Carbon Dots Dissolved Natural Water disinfection treatment processes HS detection range fluorescence quenching humic substances drinking water novel sensor surface water samples detection range Lowry method detection result HS measurement Humic Substances geochemical circulation nitrogen-doped carbon quantum dots nitrogen-doped carbon-dots fluorescence HS quantification 2017-11-17 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Quantification_of_Humic_Substances_in_Natural_Water_Using_Nitrogen-Doped_Carbon_Dots/5659006 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.