Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China; School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, PR China.
Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400044, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Jan 15;225:117470. doi: 10.1016/j.saa.2019.117470. Epub 2019 Aug 26.
In this work, we presented a sensitive and selective colorimetric and fluorescent dual-readout sensor based on Griess assay for nitrite (NO) detection under acidic condition. The sensor system was constituted of acid-resistant carbon quantum dots (CQDs) and 3-aminophenol (3-Aph) with acidic condition regulated using HCl. During the sensing procedure, reaction of 3-Aph and NO under acidic condition can yield a yellow-colored azoic compound (AZO), which gives the colorimetric readout; meanwhile, the fluorescence of CQDs (fluorescence reporter) quenched due to the strong absorption of AZO, leading to fluorescent readout. Wherein, CQDs were synthesized via hydrothermal method through using polyacrylamide as precursor and characterized by AFM, XRD and XPS. Under the optimized condition, the sensor exhibit broad linear relationships towards NO in the range of 10 to 100 nM and 2.5 to 100 μM, with practical detection limits of 10 nM and 2.5 μM for the fluorescent and colorimetric readout, respectively. And the sensor displayed excellent capability of selectivity according to interferences study. Furthermore, testing of sprouts, bacon and ham sausage real samples demonstrated good recoveries and reproducibility of the sensor system. All these results suggested the presented colorimetric and fluorescent dual-readout sensor can be a promising candidate for the NO detection in real applications.
在这项工作中，我们提出了一种基于格里斯测定法的灵敏、选择性的比色和荧光双读传感器，用于在酸性条件下检测亚硝酸盐（NO）。该传感器系统由耐酸碳量子点（CQDs）和 3-氨基酚（3-Aph）组成，通过使用 HCl 调节酸性条件。在传感过程中，3-Aph 和 NO 在酸性条件下的反应可以生成黄色偶氮化合物（AZO），从而实现比色读数；同时，由于 AZO 的强吸收，CQDs 的荧光（荧光报告）被猝灭，导致荧光读数。其中，CQDs 通过水热法合成，使用聚丙烯酰胺作为前体，并通过 AFM、XRD 和 XPS 进行了表征。在优化条件下，该传感器对 NO 的荧光和比色读数的线性范围分别为 10 至 100 nM 和 2.5 至 100 μM，荧光和比色读数的实际检测限分别为 10 nM 和 2.5 μM。并且根据干扰研究，该传感器显示出优异的选择性能力。此外，对豆芽、培根和火腿香肠实际样品的测试表明，该传感器系统具有良好的回收率和重现性。所有这些结果表明，所提出的比色和荧光双读传感器可以成为实际应用中检测 NO 的有前途的候选者。
