Rhodiola rosea Rhizome Extract-Mediated Green Synthesis of Silver Nanoparticles and Evaluation of Their Potential Antioxidant and Catalytic Reduction Activities

Daihua Hu; Xu Yang; Wang Chen; Zili Feng; Chingyuan Hu; Fei Yan; Xiaohua Chen; Dong Qu; Zhiyuan Chen

doi:10.1021/acsomega.1c02843

Rhodiola rosea Rhizome Extract-Mediated Green Synthesis of Silver Nanoparticles and Evaluation of Their Potential Antioxidant and Catalytic Reduction Activities

ACS Omega. 2021 Sep 14;6(38):24450-24461. doi: 10.1021/acsomega.1c02843. eCollection 2021 Sep 28.

Authors

Daihua Hu^{1

2

3}, Xu Yang¹, Wang Chen¹, Zili Feng¹, Chingyuan Hu³, Fei Yan³, Xiaohua Chen³, Dong Qu³, Zhiyuan Chen³

Affiliations

¹ Vitamin D Research Institute, College of Bioscience and Bioengineering, Shaanxi University of Technology, Hanzhong, Shaanxi 723000, China.
² College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
³ Shaanxi Key Laboratory of Bioresource, College of Bioscience and Bioengineering, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, China.

Abstract

The silver nanoparticles (AgNPs) using the rhizome extract of Rhodiola rosea have been reported. However, their antioxidant activity and whether the biogenic AgNPs could be used to catalyze the reduction of hazardous dye or used as fluorescence enhancers are unknown. This study focused on the facile green synthesis of silver nanoparticles using the rhizome aqueous extract of R. rosea (G-AgNPs). We then studied their antioxidant activity and catalytic degradation of hazardous dye Direct Orange 26 (DO26) and Direct Blue 15 (DB15). Their effects on fluorescein's fluorescent properties were also evaluated. The chemical AgNPs (C-AgNPs) were synthesized by reducing solid sodium borohydride (NaBH₄), and its above activities were compared with those of G-AgNPs. The formation of G-AgNPs was confirmed by the appearance of brownish-gray color and the surface plasmon resonance (SPR) peak at 437 nm. The biogenic AgNPs were approximately 10 nm in size with a regular spherical shape identified from transmission electron microscopy (TEM) analysis. G-AgNPs exhibited significantly improved 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity than butylated hydroxytoluene (BHT) and C-AgNPs (p < 0.05). The biogenic G-AgNPs were also found to function as an effective green catalyst in reducing DO26 and DB15 by NaBH₄, which is superior to C-AgNPs. Furthermore, G-AgNPs showed better fluorescence enhancement activity than C-AgNPs, and the concentration required was lower. When the concentration of the G-AgNP solution was 64 nmol/L, the fluorescence intensity reached the maximum of 5460, with the fluorescence enhancement efficiency of 3.39, and the fluorescence activity was stable within 48 h. This study shows the efficacy of biogenic AgNPs in catalyzing the reduction of hazardous dye DO26 and DB15. Biogenic AgNPs could also be used as fluorescence enhancers in low concentrations.