Green synthesis of iron oxide nanorods using Withania coagulans extract improved photocatalytic degradation and antimicrobial activity

Highlights

• Synthesis of Iron Oxide NRs through chemical & Biological Method

• Characterizations of Iron Oxide NRs

• Degradation of Safranine dye under solar radiation

• Mechanistic investigation of Degradation

• Antimicrobial activities of Iron Oxide NRs by chemical & Biological Method

Abstract

Present work compares the green synthesis of iron oxide nanorodes (NRs) using Withania coagulans and reduction precipitation based chemical method. UV/Vis confirmed the sharp peak of Iron oxide NRs synthesized by biologically and chemically on 294 and 278 nm respectively. XRD and SEM showed highly crystalline nature of NRs with average size 16 ± 2 nm using Withania extract and less crystalline with amorphous Nanostructure of 18 ± 2 nm by chemical method. FTIR analysis revealed the involvement of active bioreducing and stabilizing biomolecules in Withania coagulans extract for synthesis of NRs. Moreover, EDX analysis indicates 34.91% of Iron oxide formation in biological synthesis whereas 25.8% of iron oxide synthesis in chemical method. The degradation of safranin dye in the presence of Withania coagulans based NRs showed 30% more effectively than chemically synthesized Nanorods which were verified by the gradual decrease in the peak intensity at 553 nm and 550 nm respectively under solar irradiation. Furthermore, Withania coagulans based NRs showed effective Antibacterial activity against S.aureus and P. aeuroginosa as compared to NRs by chemical method. Finally, we conclude that green synthesized NRs are more effective and functionally more efficient than chemically prepared NRs. Therefore, our work will help the researchers to boost the synthesis of nanoparticles via biological at commercial level.

Introduction

Synthesis of functional nanomaterials is flourishing as the most favourable domain of researchers due to their immense applications like in bimolecular imaging, therapeutics, drugs delivery, biomedicines, cancer treatment, cosmetic surgery and molecular based detection etc. [[1], [2], [3], [4], [5], [6]]. By considering these remarkable applications, scientists are attempting to synthesize functional nanomaterials by a variety of physical, chemical and biological methods [[7], [8], [9], [10], [11], [12], [13]]. Physical and Chemical method used for the production of Nanoparticles (NPs), with narrow range of size and morphology [[14], [15], [16]] but it is relatively expensive and involve the use of different chemicals which are potentially hazardous to environment and also responsible for various biological risks while green synthesis of NPs, which utilized different biological resources like plants, fungi and microorganism for production of NPs that are eco-friendly, prevent pollution and wastes production, efficient synthesis, time and energy saving and the most importantly its economical production of NPs. Recently there have been some reports of biological synthesis of Iron oxide nanoparticles by using extract of different plants like, Lagenaria siceraria, Camellia sinensis, Glycosmi mauritiana, Eichhornia crassipes, Fagonia cretica, Dracinea cochenchinesis and Artemisia vulgaris [[17], [18], [19], [20], [21]]. But it is revealed that the nanoparticles synthesized by chemical method are different in properties regarding practical application such as antimicrobial activity and photodegradation properties as compared to biologically synthesized nanoparticles. Multiple approaches are used to synthesized nanoparticles where they can make changes in the structure, shape, composition and surface chemistry to optimized the synthesis for further advance and vast application. The nanoparticles are modified by different methods so that effectiveness and effiecny is increased in the particular treated environment. There are many reports on synthesis of iron oxide nanoparticles However, there have been fewer studies on fabricating iron nanorods via green synthesis and their application for biological materials [[22], [23], [24]]. There is an urgent need to search out biological approach such as Wathiana coagulans extract for FeO-NRs synthesis that proved to be a good, efficient, and promising antibacterial candidate due to its cost-effectiveness, non-toxicity, and facile synthesis procedures in therapeutic biomedical fields. Keeping in view the effectiveness of iron oxide NRs on commercial scale including the photodegradation of dye such as Safranin which is very important for biological stain in histology and cytology. It is used as a counter-stain in some staining protocols, coloring cell nuclei red. This is the classic counterstain in both Gram stains and endospore staining. Safranin can also be used for the detection of cartilage, mucin and mast cell granules[25]. Furthermore, iron oxide NRs contribute toward antibacterial activity toward common infections bacterial strains.

In present work we have explored the efficiency of green synthesis and chemical precipitation method. In biological synthesis we have utilized a new plant named Withania coagulans as a reducing and capping agent for the synthesis of Iron oxide nanorodes that is not reported yet. Due to its high production rate, cost effectiveness as well as no interference of hazardous chemicals and any bacterial or fungal species which eradicate all associated clinical issues, hence, make Withania coagulans extract distinct bio reducing source to discover the new horizons of bio nanomaterials [[26], [27], [28]]. Where as in in chemical method we have employed FeCl₃ as a precursor for the synthesis of Iron oxide nanorodes. Next the wide applicated phenomena as photocatalytic degradation of important dye and antibacterial activities against most common infectious strains had been tested to make this less pensive, abundantly found Waithania at commercial scale. The biological approach was compared with chemical method to demonstrate and evaluate the difference among both possible outcomes and the reliabilities should be preferably used in various biomedical applications such as bio-nanotechnology, biomedicines and pharmaceuticals [[29], [30], [31], [32]].