Zinc oxide nanoparticles: Biosynthesis, characterization, biological activity and photocatalytic degradation for tartrazine yellow dye

The present study aims to synthesize/characterize zinc oxide nanoparticles (ZnO-NPs) to evaluate the application of tartrazine yellow (TY) dye removal. ZnO-NPs were synthesized by the biosynthesis method from Eucalyptus grandis extract. X-ray diffraction (XRD), zeta potential (ZP), N-2 porosimetry, Field Emission Gun Scanning Electron Microscope (FEG-SEM), zero charge point (pHZCP) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) were used to the ZnO-NPs charac-terization. The antimicrobial activity was performed by the MIC (Minimum Inhibitory Concentration) method against gram-positive (S. aureus) and gram-negative (E. coli, K. pneumoniae and P. aeruginosa) strains. For cellular activity assays, MTT (3-(4,5-Dimethylthiazol-2-yl) and DCFH-DA (2'7' dichlorofluo-rescein diacetate) tests were performed with cell lines of the 293T, A549 and U87MG. FEG-SEM microg-raphy indicated a heterogeneous and porous morphology with rod-shaped zinc oxide nanoparticles (particle size ranged from 40 to 50 nm). ZnO-NPs showed a negative charge surface (-11.6 +/- 0.2 mV), pH(ZCP) approximate to 003; 7.16 with type III and H1 hysteresis (S-BET = 3.9 m(2)/g, and Dp = 16.2 nm) indicating a mesoporous material with pores open at both ends. The optimal condition was [ZnO-NPs] = 0.6 g/L, [TY] = 20 mg/L and pH approximate to 6.0 with 76.1 % (k = 0.0077 min(-1)) for the TY photodegradation under visible radiation, and after VI cycles of ZnO-NPs recycling, there was a decrease of only 6 %. ZnO-NPs showed antimicrobial activity of 0.625 mg mL(-1), as well as a decrease in cell viability in the three tested lines in 100 and 300 lg mL(-1). Therefore, ZnO-NPs showed potential application for TY photodegradation to be used in wastewater treatment and nanomedicine. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The present study aimed to synthesize/characterize zinc oxide nanoparticles (ZnO-NPs) for tartrazine yellow (TY) dye removal. ZnO-NPs were synthesized from Eucalyptus grandis extract. Various tests were conducted to characterize the ZnO-NPs. Results showed that ZnO-NPs had a rod-shaped structure and exhibited antimicrobial activity. The optimal conditions for TY photodegradation were determined, and ZnO-NPs demonstrated potential applications in wastewater treatment and nanomedicine.