Optimization of physicochemical parameters in the biofabrication of gold nanoparticles using marine macroalgae Padina tetrastromatica and its catalytic efficacy in the degradation of organic dyes

Abstract

Green synthesis of metallic nanoparticles by means of renewable bioresources has emerged as a new trend in current nanotechnology research with improved environmental safety. In the current study, monodispersed gold nanoparticles (AuNPs) with excellent stability were prepared in a completely green and cost effective manner using aqueous extract of marine macroalgae-Padina tetrastromatica. The influence of reaction conditions such as the quantity of seaweed extract, temperature, precursor metal ion concentration, reaction time and pH on the biosynthesis of nanoparticle was evaluated spectroscopically and also with the help of high resolution transmission electron microscopy (HR-TEM). These physicochemical parameters not only affected the rate of formation but also the size and morphology of resultant nanoparticles. Optimum conditions resulted in the generation of nearly spherical AuNPs having an average particle size of 11.4 nm. The high crystallinity of the biogenic AuNPs was confirmed from characteristic diffraction peaks in XRD profile, clear lattice fringes in the HR-TEM image and bright circular spots in the SAED pattern. The presence of metallic gold was evidenced from EDAX profile. FTIR study revealed the role of secondary metabolites in the bioreduction as well as stabilization of AuNPs. The study also highlights the spectroscopic investigation on the catalytic efficacy of the biosynthesized AuNPs in the reduction reactions of hazardous organic dyes, eosin yellow and Congo red using sodium borohydride, which have a pseudo-first order kinetics. Thus, the biosynthesized metal nanoparticles using renewable marine resources like seaweeds act as promising materials for the application in environmental protection.

Gold nanoparticles induced apoptosis via oxidative stress and mitochondrial dysfunctions in MCF‐7 breast cancer cells

“…A further rise in the HAuCl 4 concentration resulted in a shift to a longer wavelength owing to the rise in particle size. Such findings were consistent with prior investigations conducted by Bankar et al [ 16 ] and Princy et al [ 34 ] where it was confirmed that 1.0 mM HAuCl 4 was found to be the best for the synthesis of AuNPs. Similarly, among the different volumes of P. alata extract tested, synthesis using 1.0 ml of the extract showed increased production of AuNPs with an intensity absorbance peak at 530 nm.…”

“…The UV-Vis spectra ( Figure 2) depicted strong intense SPR peaks for Ah-AuNPs (534.4 nm), Li-AuNPs (537.6 nm), Mc-AuNPs (538.4 nm), Cl-AuNPs (548.3 nm), Pa-AuNPs (529.6 nm), and Vi-AuNPs (531.5 nm). Similar observations of apparent color change from pale yellow to pink, [34] ruby red, [23] and violet [35] with the peak absorptions between 525 and 550 nm have been recorded, suggesting the formation of AuNPs. Therefore, the six synthesized AuNPs alone chosen for further screening study of antioxidant activity.…”

<p>Synthesis of Silver Nanoparticles Using a Novel Cyanobacteria <em>Desertifilum</em> sp. extract: Their Antibacterial and Cytotoxicity Effects</p>

“…6 Advances in NP synthesis and increased use of these particles in many fields have led researchers to evaluate mechanisms to improve the biocompatibility of NPs. 7,8 In addition, increased use of NPs has resulted in interest in the development of green approaches for the fabrication of NPs. Biological synthesis has several advantages including reduced production of toxic by-products, improved stability, and reduced toxicity against healthy cells.…”

Two fold increase in synthesis of gold nanoparticles assisted by proteins and phenolic compounds in Pongamia seed cake extract: response surface methodology approach

“…The experiments were performed by varying one factor at a time by keeping other factors at a fixed value. Surface plasmon resonance (SPR) Peak was recorded at 530 nm as it is evident from literature reports that blue shift is seen due to decrease in particle size owing to monodispersed nature of nanoparticles [17]. Similarly, experiments were performed by varying other factors and keeping previously varied factors at the optimized values.…”