A world wide easily available, economical, and sustainable carbonaceous source based on kitchen derived waste tea residue (containing sugar and milk) was used for the synthesis of carbon dots (CDs). Pyrolysis of waste tea residue in controlled condition was employed to synthesis water soluble carbon dots (WTR-CDs). The as-synthesised WTR-CDs exhibited emission at 415 nm, excitation dependent behavior, stability towards the pH and ionic strength. The emission intensity of WTR-CDs dwindled with an addition of hypochlorite ion (ClO⁻) and designed sensor achieved sensitive detection of free chlorine rapidly with higher selectivity over twenty-one (21) common interfering ion tested. WTR-CDs showed good response over a range of 0.02–2.0 µg mL⁻¹ of ClO⁻. Furthermore, the Stern-Volmer equation was used to obtain calibration curve displayed a very good linear response for the analyte within the range 0.02–0.30 µg/mL with the lowest limit of detection (LOD) is 0.038 µg/mL. Moreover, potential applications of this developed method were explored in various water bodies by standard addition method which finds a new avenue for the quantification of free chlorine and water quality monitoring.

基于厨余废茶残渣（含糖和牛奶）的世界范围内易于获得，经济且可持续的碳源被用于碳点（CD）的合成。将废茶渣在受控条件下进行热解，以合成水溶性碳点（WTR-CD）。合成后的WTR-CD表现出在415 nm处的发射，激发相关的行为，对pH值和离子强度的稳定性。WTR-CD的发光强度逐渐减少，并加次氯酸根离子的（CLO ^- ）和设计的传感器在21测试（21）共同的干扰离子实现游离氯的灵敏检测快速具有较高的选择性。WTR-CD的显示在一定范围的0.02-2.0微克毫升良好响应^-1 CLO的^-。此外，使用Stern-Volmer方程获得的校准曲线显示出在0.02–0.30 µg / mL范围内分析物具有很好的线性响应，最低检测限（LOD）为0.038 µg / mL。此外，通过标准添加方法探索了该开发方法在各种水体中的潜在应用，这为定量分析游离氯和监测水质提供了新途径。