Precisely Controllable Core-Shell Ag@Carbon Dots Nanoparticles: Application to in Situ Super-Sensitive Monitoring of Catalytic Reactions

Jing Jin; Shoujun Zhu; Yubin Song; Hongyue Zhao; Zhen Zhang; Yue Guo; Junbo Li; Wei Song; Bai Yang; Bing Zhao

doi:10.1021/acsami.6b07807

Precisely Controllable Core-Shell Ag@Carbon Dots Nanoparticles: Application to in Situ Super-Sensitive Monitoring of Catalytic Reactions

ACS Appl Mater Interfaces. 2016 Oct 19;8(41):27956-27965. doi: 10.1021/acsami.6b07807. Epub 2016 Oct 10.

Authors

Jing Jin¹, Shoujun Zhu¹, Yubin Song¹, Hongyue Zhao¹, Zhen Zhang², Yue Guo¹, Junbo Li¹, Wei Song¹, Bai Yang¹, Bing Zhao¹

Affiliations

¹ State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
² Alan G. MacDiarmid Institute, College of Chemistry, Jilin University , Changchun, 130012, P. R. China.

PMID: 27673572
DOI: 10.1021/acsami.6b07807

Abstract

Carbon dots (CDs) have attracted extensive interest owing to their unparalleled physical and chemical characteristics. CDs based nanocomposites have also drawn increasing attention because the combination of different characteristics could offer additional brilliant properties (such as photocatalysis and Raman scattering). In this work, we developed a fast, facile, and controllable method for fabricating core-shell Ag@CDs nanoparticles (NPs) based on the ability of CDs to directly reduce Ag⁺ to Ag NPs without an external photoirradiation process or additional reductants. The as-prepared Ag@CDs NPs caused efficient CDs fluorescence quenching, and the typical bands of carbon species were obtained in the Raman spectrum of CDs. In addition, we found that the Ag@CDs NPs could be utilized as an efficient surface-enhanced Raman scattering (SERS) substrate, showing a discernible detection concentration as low as 10^-8 M by using p-aminothiophenol (PATP) as the probe molecules. The as-prepared Ag@CDs NPs used as the SERS substrate also exhibited excellent peroxidase-like catalytic activity for in situ super-sensitive monitoring of the oxidation of 3,3',5,5'-tetramethylbenzidine by H₂O₂, a plasmon-enhanced driven photocatalytic reaction of p-nitrothiophenol (PNTP) dimerizing into 4,4'-dimercaptoazobenzene, and catalytic driven reduction of PNTP to PATP in the presence of NaBH₄ in real time. Moreover, the determination of H₂O₂ with a significantly lower discernible detection concentration was obtained. This work demonstrated that the hybrid nanostructures not only exhibited unique SERS properties but also showed excellent catalytic activities, especially as an ultrasensitive SERS substrate for monitoring heterogeneous catalytic reactions in real time. This would make it possible to not only obtain the information about catalytic molecular changes but also conduct quantitative and qualitative analysis, and widen the application of CDs in SERS and catalytic reactions.

Keywords: carbon dots; catalytic reactions; nanoparticles; silver; surface-enhanced Raman spectroscopy.