OICC Press Journal of Nanostructure in Chemistry 2193-8865 12 1 (February 2022) 2021 04 26 Functionalization of selenium nanoparticles using the methanolic extract of Cirsium setidens and its antibacterial, antioxidant, and cytotoxicity activities 10.1007/s40097-021-00397-7 EN Sukjin Shin Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Kandasamy Saravanakumar Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Arokia Vijaya Anand Mariadoss Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Xiaowen Hu Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Anbazhagan Sathiyaseelan Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Myeong-Hyeon Wang Department of Bio-Health Convergence, Kangwon National University, Chuncheon, 200-701, KR Journal Article 2021 04 26 Abstract Selenium (Se) is a noble mineral that prevents oxidative stress and regulates metabolism by balancing the level of antioxidants in human body. The present work was the first time report of the comparative analysis of bioactivities of selenium nanoparticles (CS-SeNPs and AA-SeNPs) synthesized by Cirsium setidens extracts (CSE) and ascorbic acid (AA), respectively. The CS-SeNPs exhibited an average particle size of 117.8 nm with PDI of 0.162 and zeta potential of − 27.4 mV while average particle size of 108.9 nm with PDI 0.062 and zeta potential of − 32.4 mV for AA-SeNPs. FTIR analysis indicated the surface capping of phyto-compounds of CSE on CS-SeNPs while AA-SeNPs exhibited the functional groups corresponding to AA. The CS-SeNPs exhibited higher DPPH, ABTS, and antibacterial activities than CSE but less than AA-SeNPs. Moreover, both nanoparticles were nontoxic to normal fibroblast cell line (NIH3T3), but cytotoxic to human lung cancer cell line (A549). This work concluded that CS-SeNPs is promising in inhibition of A549 cell line proliferation through damaging the nucleus and mitochondrial membrane.