Biogenic Synthesis and Catalytic Efficacy of Silver Nanoparticles Based on Peel Extracts of Citrus macroptera Fruit

Abstract

Biogenically synthesized silver nanoparticles (AgNP) increase the fascination over chemical ones due to their facile and green synthetic process. This study reports the development of an eco-friendly and cost-effective synthesis of AgNPs using an aqueous extract of Citrus macroptera fruit peel, an agricultural waste, as a sole agent with both reducing and capping abilities. The formation of AgNPs was verified by the surface plasmon resonance peak at 426 nm in the UV−vis spectrum, X-ray diffraction pattern, and transmission electron micrography images. The AgNPs obtained under the optimized conditions consist of face-centered cubic crystals and spherical morphology with an average size of 11 nm. The AgNPs are coated with phytochemicals in the C. macroptera fruit peel extract and are stably dispersible due to their negatively charged nature. The AgNPs effectively catalyzed the reduction of 4-nitrophenol to 4-aminophenol and the degradation of methyl orange and methylene blue in the presence of sodium borohydride. This method employing a fruit peel extract is facile, efficient, eco-friendly, and cost-effective and has potential for industrial green fabrication of AgNPs.

Biogenic Silver Nanoparticles: What We Know and What Do We Need to Know?

“…The authors concluded that bio-AgNPs can be used as powerful tools for reducing environmental pollution from organic dyes [221]. The reduction of 4-NP to 4-AP and the degradation of methyl orange (MO) and MB in the presence of sodium borohydride and catalyzed by bio-AgNPs synthesized using aqueous extract of fruit peel (Citrus macroptera) and bacteria (Bacillus cereus) were also reported recently [190,222]. Considering the above facts, it can be inferred that bio-AgNPs can be used as catalysts for the degradation of dyes.…”

“…Biogenic AgNPs act as catalysts for the degradation of organic dyes (methylene blue, methyl orange, congo red tartrazine, carmoisine, and brilliant blue FCF) and other toxic compounds such as 4-nitrophenol to non-toxic compounds [220][221][222], which reduces environmental pollution [221]. Bio-AgNPs synthesized from aqueous Prosopis juliflora leaves extract were evaluated for catalytic activity against azo dyes such a methylene blue (MB) and congo red (CR) that resulted in its effective degradation of toxic compounds in a short span of time.…”

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

“…The other signals can be attributed to the organic capping layer. The significant intensity of the peaks indicates the presence of a sufficient coating layer on the biosynthesized AgNPs [ 27 , 61 , 76 ].…”

“…The dense peak corresponding with silver strongly confirmed the reduction of AgNO 3 and the formation of AgNPs. An EDX analysis also proved that the required phase of silver was present in the biosynthesized AgNPs [ 27 , 61 , 63 , 76 , 91 ]. The crystalline nature of the biosynthesized AgNPs was confirmed in the form of XRD diffraction peaks at 2θ = 37°, 49°, 63°, and 76° (corresponding to the planes of silver 111, 200, 220, 311), respectively ( Figure 4 ), which are typical XRD values of biosynthesized AgNPs [ 65 , 76 , 92 , 93 , 94 ].…”

“…Biological synthetic pathways based on microorganisms or plant extracts have been widely explored for the production of AgNPs in several applications as they are environmentally friendly and often inexpensive. Moreover, plant-based extract-mediated AgNPs synthesis is more advantageous than other biological processes because it does not require stringent aseptic environments and strict monitoring of cell culture conditions [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. The genus Bauhinia is a member of the Leguminosae family (subfamily Caesalpiniaceae) and consists of about 300 species.…”