Preparation of Highly Catalytic N-Doped Carbon Dots and Their Application in SERS Sulfate Sensing

• Published in: Materials Vol. 11; no. 9; p. 1655
• Main Authors: Wang, Libing, Li, Chongning, Luo, Yanghe, Jiang, Zhiliang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.09.2018; MDPI
• Subjects: Barite; Barium sulfate; Carbon; Carbon dots; Catalysis; Catalysts; Catalytic activity; Fluorescence; gold nanoreaction; Graphene; Hydrogen peroxide; N-doped carbon dots; Nanoparticles; Quantitative analysis; Quantum dots; Reagents; Scanning electron microscopy; SERS; Silicon wafers; Substrates; United Kingdom > UK; China; Japan; catalysis; gold nanoreaction; N-doped carbon dots; SERS
• ISSN: 1996-1944; 1996-1944
• 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.