Monascus pigment‐mediated green synthesis of silver nanoparticles: Catalytic, antioxidant, and antibacterial activity

Abstract

In order to explore green and efficient methods for the synthesis of nanoparticles, silver nanoparticles (AgNPs) were rapidly synthesized assisted by the Monascus pigments under simulated sunlight. Prepared AgNPs were characterized using various analytical tools such as ultraviolet‐visible (UV–Vis) spectroscopy, Zeta, X‐ray diffraction (XRD), scanning electron microscopy (SEM)–energy dispersive X‐ray (EDX), and Fourier‐transform infrared spectroscopy (FT‐IR). There is an absorption peak at 410 nm in the UV–Vis absorption spectrum, which confirms the formation of AgNPs. XRD results affirmed that the synthesized AgNPs were crystalline in nature and preferentially oriented in (111) plane. The morphology of the nanoparticles was found to be spherical by SEM and particle size analysis study revealed the average particle size to be 18.10 ± 0.30 nm. Zeta potential measurement showed excellent stability of AgNPs with negative values of −9.2 ± 0.66 mV. The FT‐IR study represented involvement of functional groups in AgNPs synthesis. The biosynthesized AgNPs exhibited significant antibacterial activity with zones of inhibition of 9.1, 14.5, and 18.0 mm against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, respectively. Through the determination of hydroxyl radical scavenging capacity, ABTS radical scavenging capacity, total reducing power, and total antioxidant capacity, it is proved that the AgNPs have certain antioxidant capacity. In addition, AgNPs could catalyze the degradation of methylene blue, methyl orange, and congo red with a pseudo first‐order rate constants of 0.07998, 0.24666, and 0.11805 min−1, respectively. Overall studies indicated that the Monascus pigments could be used to prepare AgNPs with potential antibacterial, antioxidant, and extraordinary catalytic activity. It can be used in biomedical applications, commercial food packaging, pathogen mitigation, and industrial waste water management.

Eco-Friendly Green Synthesis of Rubropunctatin Functionalized Silver Nanoparticles and Evaluation of Antibacterial Activity

“…The formation of R-AgNPs was further monitored and confirmed by UV-Vis spectroscopy. Due to the surface plasmon resonance (SPR) phenomenon of R-AgNPs, R-AgNPs exhibits a visible UV absorption peak at 410 nm which is consistent with the SPR absorption peak of AgNPs in the range of 400-420 nm [33]. On the other hand, no SPR peak was shown in the silver nitrate solution at 300-800 nm, whereas the characteristic peak of rubropunctatin appeared at 467 nm in the rubropunctatin and silver nitrate mixture.…”

“…GL-AgNPs have good antibacterial activity against E. coli (Gramnegative) and S. aureus (Gram-positive bacteria) [37]. Rui Z et al rapidly synthesized MP-AgNPs with an average particle size of 18.10 ± 0.30 nm by monascus pigment (MP) under simulated sunlight, and demonstrated that the biosynthesized MP-AgNPs showed excellent inhibitory effects against E. coli, P. aeruginosa and S. aureus [33]. Di Filippo et al synthesized bioactive AgNPs by using snail mucus extracted from spiral snail as a bioreducing agent and bio-stabilizer.…”

Strategies on improvement of pigment formation and reduction of citrinin in Monascus fermentation

“…also reported that a more efficient and environmentally friendly silver nanoparticle synthesis process was obtained with the assistance of MPs. Based on this, the utilization of pigments can be expanded to the nanomaterials application field, like commercial food packaging, pathogen mitigation and even industrial waste water management 75 . Prospectively, since antibiotics have been banned in fodder, MPs with several beneficial bioactivities may have deeper applications in livestock breeding.…”

Comparative transcriptomics discloses the regulatory impact of carbon/nitrogen fermentation on the biosynthesis of Monascus kaoliang pigments

“…MPs can effectively lower blood pressure, reduce plasma cholesterol levels, prevent obesity, and improve anti-inflammatory activity. Moreover, they can be used to prevent cancer, reduce blood sugar levels, and possess anti-inflammatory and anti-tumor properties ( Yasukawa et al, 1996 , Nam et al, 2014 , Zhang et al, 2021 ).…”