Wang Libing, Li Chongning, Luo Yanghe, Jiang Zhiliang
School of Food and Bioengineering, Hezhou University, Hezhou 542899, China.
Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin 541004, China.
Materials (Basel). 2018 Sep 7;11(9):1655. doi: 10.3390/ma11091655.
Carbon dots (CD) have excellent stability and fluorescence activity, and have been widely used in fluorescence methods. However, there are no reports about using CD as catalysts to amplify SERS signals to detect trace sulfate. Thus, preparing CD catalysts and their application in SERS sulfate-sensing are significant. In this article, highly catalytic N-doped carbon dots (CD) were prepared by a hydrothermal procedure. CD exhibited strong catalysis of the gold nanoparticle (AuNP) reaction between HAuCl₄ and H₂O₂. Vitoria blue 4R (VB4R) has a strong SERS peak at 1614 cm in the formed AuNP sol substrate. When Ba ions were added, they were adsorbed on a CD surface to inhibit the CD catalytic activity that caused the SERS peak decreasing. Upon addition of analyte SO₄, a reaction with Ba produced stable BaSO₄ precipitate and CD, and its catalysis recovered to cause SERS intensity increasing linearly. Thus, an SERS method was developed for the detection of 0.02⁻1.7 μmol/L SO₄, with a detection limit of 0.007 μmol/L.
碳点（CD）具有出色的稳定性和荧光活性，已广泛应用于荧光方法中。然而，尚无关于使用碳点作为催化剂来放大表面增强拉曼散射（SERS）信号以检测痕量硫酸盐的报道。因此，制备碳点催化剂及其在SERS硫酸盐传感中的应用具有重要意义。在本文中，通过水热法制备了具有高催化活性的氮掺杂碳点（CD）。碳点对氯金酸（HAuCl₄）与过氧化氢（H₂O₂）之间的金纳米颗粒（AuNP）反应表现出强烈的催化作用。维多利亚蓝4R（VB4R）在形成的金纳米颗粒溶胶底物中于1614 cm处有一个很强的SERS峰。当加入钡离子时，它们吸附在碳点表面，抑制了碳点的催化活性，导致SERS峰降低。加入分析物硫酸根（SO₄）后，它与钡反应生成稳定的硫酸钡沉淀和碳点，其催化作用恢复，导致SERS强度线性增加。因此，开发了一种用于检测0.02⁻1.7 μmol/L硫酸根的SERS方法，检测限为0.007 μmol/L。
