Precisely Controllable Core-Shell Ag@Carbon Dots Nanoparticles: Application to in Situ Super-Sensitive Monitoring of Catalytic Reactions.
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 10-8M 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 NaBH4in real time. Moreover, the determination of H2O2with 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.
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Jing
J
Jin
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Shoujun
S
Zhu
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Yubin
Y
Song
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Hongyue
H
Zhao
Alan G. MacDiarmid Institute, College of Chemistry, Jilin University , Changchun, 130012, P. R. China.
Zhen
Z
Zhang
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Yue
Y
Guo
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Junbo
J
Li
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Wei
W
Song
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Bai
B
Yang
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun, 130012, P. R. China.
Bing
B
Zhao
carbon dots; catalytic reactions; nanoparticles; silver; surface-enhanced Raman spectroscopy