Chlorination is a widely adopted disinfection method in water and wastewater treatment for the protection of public health, as it greatly reduces pathogen risks and associated incidence of waterborne diseases. Chlorination, however, also creates disinfection by-products (DBPs) such as trihalomethanes, which, epidemiologically, have been associated with a higher incidence of some forms of cancer. Therefore, developing sensors for monitoring the chlorine dosage and DBPs concentrations in real-time and in-line is of critical importance to public health. Carbon dots (CDs) are an emergent class of fluorescent nanomaterial offering highly-sensitive sensing functionalities towards a diverse range of chemical/biochemical contaminants, owing to their tuneable fluorescence, rich surface functionalities, low to non-toxicity and ease of synthesis. In this study, we demonstrate that 1) highly fluorescent CDs (quantum yield 38%) can be produced from simple thermal treatment from biowastes such as human hairs without employing any solvents; 2) the fluorescence spectra and intensity of the synthesized CDs responds to the presence and quantity of chloroform with high sensitivity, with a limit of detection of 3 ppb; and 3) through a pair-wise comparative study on autoclave-synthesized CDs (OCDs) and microwave-synthesized counterpart, we discovered that the pyridinic N oxide that is unique to OCDs imparts sensitive and selective sensing functionality towards chloroform; 4) the PL-based sensing functionality is not solely determined by the binding affinity between the analyte and the carbon dots, but also the electronic structures of the interacting entities. This study provides an in-depth study on how to utilize the diverse features of biowastes and impart unique functionalities to CDs for developing advanced functional materials.

中文翻译：

---

来自人发的碳点用于水中 ppb 级氯仿传感

氯化是水和废水处理中广泛采用的消毒方法，以保护公众健康，因为它大大降低了病原体风险和相关水传播疾病的发病率。然而，氯化也会产生消毒副产物 (DBP)，例如三卤甲烷，从流行病学上讲，它与某些形式的癌症的高发病率有关。因此，开发用于实时和在线监测氯剂量和 DBPs 浓度的传感器对公共卫生至关重要。碳点 (CD) 是一类新兴的荧光纳米材料，由于其可调节的荧光、丰富的表面功能、低至无毒且易于合成，因此对各种化学/生化污染物具有高灵敏度的传感功能。在这项研究中，我们证明了 1) 高荧光 CDs（量子产率 38%）可以通过简单的热处理从生物废物（如人类头发）中产生，而无需使用任何溶剂；2）合成的CDs的荧光光谱和强度对氯仿的存在和数量反应灵敏，检测限为3 ppb；3) 通过对高压釜合成 CDs (OCDs) 和微波合成对应物的成对比较研究，我们发现 OCDs 独有的吡啶氮氧化物赋予了对氯仿的敏感和选择性传感功能；4) 基于 PL 的传感功能不仅取决于分析物和碳点之间的结合亲和力，还取决于相互作用实体的电子结构。