Synthesis of spinel ferrites nanoparticles and investigating their effect on the growth of microalgae Picochlorum sp.

Abstract

Spinel ferrites nanoparticles (SNPs) have been extensively studied, synthesized and used in many applications including wastewater treatment, biosensors and as photocatalysts. The studies of the effect of these SNPs at cellular and molecular levels and their influence in the environment are scarce. Thus, in the current study, different metal ferrite SNPs were synthesized via sol-gel-combustion route and were characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) with Energy Dispersive X-ray (EDX) and Vibrating Sample Magnetometry (VSM) analysis techniques. The effect of these SNPs on the growth of the microalgae Picochlorum sp. was then investigated. The results showed that the synthetic method used to prepare the metal ferrite SNPs leads to highly crystalline SNPs with average crystallites size between 33–36 nm except for ZnFe2O4 NPs which have crystallite size of 52 nm. The results of XRD and EDS confirmed the formation of SNPs. VSM analysis of CoFe2O4 showed the highest magnetic energy (U) and saturation magnetization (Ms) of 30870 erg/g and 60 emu/g, respectively. Although, the microalgae culture of Picochlorum sp. treated with different SNPs showed significant difference in viable cells concentration at 48 h and 72 h of incubation compared to control samples, the growth pattern of both treated and untreated samples were seen similar. This could indicate that SNPs may reduce the growth of the microalgae but will not cause severe inhibition when used at the proper concentration. This promotes their potential use for many applications.

Keywords

• growth inhibition test
• picochlorum sp.
• sol-gel-combustion method
• spinel ferrite nanoparticles (snps)
• toxicity of spinel ferrite nanoparticles
• viable cells