Green biosynthesis of zinc and selenium oxide nanoparticles using callus extract of Ziziphus spina-christi: characterization, antimicrobial, and antioxidant activity

In this present work, the plant tissue culture biotechnology was used as good approach for green biosynthesis of nanoparticles (NPs) because it is safe, clean method, and ecofriendly. Zinc and selenium oxide nanoparticles were biosynthesized using callus extract of Ziziphus spina-christi for the first time. Callus culture from young leaf of Ziziphus spina-christi on medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) produced the highest significant callus fresh weight (12 g), color, and development. The characterization of ZnONPs and SeONPs was carried out using UV–vis, FTIR, XRD, SEM, TEM, and thermal analysis; results revealed that prepared ZnONPs and SeONPs are crystalline in nanoscale with particle size between 20 and 45 nm. Antimicrobial activity of ZnONPs and SeONPs was evaluated, and results illustrated that both ZnONPs and SeONPs have potential antimicrobial activity against common human pathogens such as Gram-negative bacteria, Gram-positive bacteria, and unicellular and multicellular fungi, where SeO-NPs had antimicrobial activity higher than ZnONPs. Moreover, ZnONPs and SeONPs have a promising antioxidant activity as well as low toxicity on 1- BJ1 normal cells. Finally, a promising green biosynthesized ZnONPs and SeONPs have potential antimicrobial activity as well as antioxidant activity which will be applied for controlling of resistant microorganism.