Hollow selenium nanoparticles from potato extract and investigation of its biological properties and developmental toxicity in zebrafish embryos

A facile synthesis of hollow selenium nanoparticles (hSeNPs) was prepared using potato starch as a reducing and capping agent. The morphological and structural characters of the hSeNPs were characterised by ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) and zeta potential analyser. The optical characteristics of hSeNPs were confirmed by UV. The presence of various functional groups in the hSeNPs suspension was confirmed by FTIR. The SEM results suggested that the synthesised hSeNPs were uniformly distributed and circular in shape with a hollow. The average size of the hSeNPs was found to be around 115 nm. The EDX analysis also confirmed the presence of hSeNPs in the sample. The zebrafish embryos were treated with hSeNPs of various concentrations ranging from 10 to 50 µg/ml. Abnormalities such as improper heartbeat, embryo sac oedema, ocular oedema and head oedema were noted at higher concentrations (30-50 µg/ml). A concentration-dependent antioxidant activity of hSeNPs was observed. The hSeNPs showed good antibacterial activity against gram-positive Bacillus subtilis and gram-negative Escherichia coli. The results of this study indicate that potato extract reduces the toxicity of hSeNPs and lower concentrations of hSeNPs could be used for various biomedical applications in near future.

Size dependent effects of antifungal phytogenic silver nanoparticles on germination, growth and biochemical parameters of rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L)

Advancement in materials synthesis largely depends up on their diverse applications and commercialisation. Antifungal effects of phytogenic silver nanoparticles (AgNPs) were evident, but the reports on the effects of the same on agricultural crops are scant. Herein, we report for the first time, size dependent effects of phytogenic AgNPs (synthesised using Stevia rebaudiana leaf extract) on the germination, growth and biochemical parameters of three important agricultural crops viz., rice (Oryza sativa L), maize (Zea mays L) and peanut (Arachis hypogaea L). AgNPs with varied sizes were prepared by changing the concentration and quantity of the Stevia rebaudiana leaf extract. As prepared AgNPs were characterized using the techniques, such as high-resolution transmission electron microscopy, particle size and zeta potential analyser. The measured (dynamic light scattering technique) average sizes of particles are ranging from 68.5 to 116 nm. Fourier transform infrared studies confirmed the participation of alcohols, aldehydes and amides in the reduction and stabilisation of the AgNPs. Application of these AgNPs to three agricultural crop seeds (rice, maize and peanut) resulted in size dependent effects on their germination, growth and biochemical parameters such as, chlorophyll content, carotenoid and protein content. Further, antifungal activity of AgNPs also evaluated against fungi, Aspergillus niger.