Biogenic ZnO Nanoparticles Research Articles

Phytoassisted synthesis of biogenic ZnO nanoparticles using Annona squamosa L. bark extract: characterization and its application studies

ABSTRACT The current research aspires to explore the novel utilization of Annona squamosa bark extract consisting of various phytochemical components as a capping agent with zinc acetate as a precursor to form zinc oxide particles. The origination of ZnO NPs is implied by the UV-Visible absorption band at 357 nm and the distinctive XRD peaks at the appropriate positions. The occurrence of highly crystalline, hexagonal phase, and impurity-free As-ZnO NPs was made apparent by the XRD pattern. Employing XRD, the average particle size from the crystallites has been identified to be 56.23 nm. The FTIR spectral analysis verified the existence of biomolecules on the ZnO NP surface. These ZnO NPs have hexagonal structures and flake-like morphology as revealed by FESEM analysis, respectively. EDS study proved the existence of Zn (51.77 weight%) and O (20.56 weight%). The fabricated As-ZnO NPs demonstrated outstanding efficacy in various biological applications, spanning in vitro antimicrobial, antioxidant, antihemolytic, antiinflammatory, antidiabetic, and anticancer properties. On top of that, As-ZnO NPs had a high degree of photocatalytic activity against methylene blue dye, with a degradation efficiency of 93.37% within 150 min exposure to sunlight.

Biogenic ZnO Nanoparticles Effectively Alleviate Cadmium-Induced Stress in Durum Wheat (Triticum durum Desf.) Plants

Biogenic ZnO Nanoparticles Effectively Alleviate Cadmium-Induced Stress in Durum Wheat (Triticum durum Desf.) Plants

Physical and thermal improvement of bioplastics based on potato starch/agar composite functionalized with biogenic ZnO nanoparticles

This study investigated potato starch/agar-based bioplastics' structure, properties, and biodegradability by adding ZnO nanoparticles (NPs) biogenically synthesized using Coriandrum sativum extract. ZnO NPs presented crystalline structure, good optical properties, and a size of 6.75 ± 1.4 nm, which were added at various concentrations (419.66–104.23 ppm) in bioplastics and their presence was confirmed via EDS elemental analysis and X-ray fluorescence. The highest NPs concentration contributed to a smoother surface, while FTIR and Raman analyses suggested interactions between the NPs and functional groups of the biopolymeric matrix. ZnO NPs addition slightly reduced bioplastic transparency but significantly improved UV-A and UV-B blocking capacities. It also increased hydrophobicity, evidenced by a 22 % reduction in water absorption and a 55 % increase in contact angle. Thermogravimetric analysis (TGA) indicated that NPs raised the bioplastic's thermal stability. Mechanical property tests showed that ZnO NPs concentrations had negligible or negative effects probably due to the heterogeneous distribution of NPs, or the non-isotropic characteristic of the bioplastic. Finally, biodegradability assays in seawater and soil revealed over 43.5 % and 66 % degradation after 15 and 28 days, respectively. Therefore, biosynthesized ZnO NPs mainly enhanced the bioplastic's UV-blocking capacity, hydrophobicity, and thermal properties, offering an eco-friendly option for future studies/applications.

Biogenic ZnO nanoparticles synthesized using Halimeda opuntia seaweed extract: A sustainable approach for promoting horse gram seed germination

Biogenic ZnO nanoparticles synthesized using Halimeda opuntia seaweed extract: A sustainable approach for promoting horse gram seed germination

Green marvel: Harnessing spinach leaves' power for enhanced photodegradation of various effluents with biogenic ZnO nanoparticles

This study investigates the use of ZnO NPs (Zinc oxide nanoparticles) derived from spinach leaf extracts in a sustainable photocatalytic technology to enhance the decomposition of hazardous effluents from refineries and paper mills. The biosynthesized ZnO NPs were characterized through X-ray diffraction (XRD), UV-Vis spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD analysis reveals that ZnO NPs possess a hexagonal wurtzite structure, exhibiting a preferred arrangement of (101) planes. The synthesized ZnO NPs have a spherical shape, as seen in the SEM images. TEM analysis detected the size of the ZnO NPs to be between 35 and 40 nm. The results indicate that ZnO NPs produced via biosynthesis have photocatalytic activity in efficiently decomposing the organic chemicals found in gasoline refining effluent when exposed to light. At a pH of 8, the ZnO NPs exhibited the highest rate of degradation for toluene (84.26 %) and xylene (90.36 %) after being exposed to simulated sunlight for 240 min. In the context of the photocatalytic treatment of paper mill effluents, it has been shown that the subsequent cycles resulted in a reduction in chemical oxygen demand (COD) levels of 81.24 %, 74.14 %, 68.92 %, 60.24 %, and 53.82 %, respectively.

Biogenic ZnO Nanoparticles Derived from Garcinia gummi-gutta Leaves: Synthesis, Characterization and its Multifaceted Applications

The current study focused on the bioreduction synthesis of ZnO nanoparticles using Garcinia gummi-gutta leaf extracts. The UV-vis analysis of the nanoparticles has reported the formation of an SPR peak at 379 nm. The functional groups taking part in the reduction reaction were analyzed using the FTIR technique and the average crystalline size of ZnO nanoparticles were found to be 22.27 nm from XRD measurements. The SEM and TEM images revealed the hexagonal shape of the nanoparticles with an average size 72.78 nm and 71.91 nm, respectively. Further, the synthesized nanoparticles were reported to be efficient degradation reactive textile dyes. The photodegradation results reported 92-100% degradation of the reactive dyes within 80-320 min. The antibacterial efficacy of the nanoparticles was investigated and the MIC of the nanoparticles was found to be 100 µg/mL. The synthesized ZnO nanoparticles have exhibited significant cytotoxic effects on the MCF and HEP-G2 cell lines.

Enhanced antimicrobial efficacy of biogenic ZnO nanoparticles through UV-B activation: A novel approach for textile garment

Zinc oxide nanoparticles (ZnO NP) are characterized by novel properties which have been attracting the attention of different lines of research due to their wide applicability. Obtaining this nanomaterial is strongly linked to biogenic synthesis methods, which have also been developed in this research, using Coriandrum sativum extract as a reducing agent. ZnO NPs have been properly characterized by techniques to evaluate their morphology by transmission electron microscopy (TEM) and elemental analysis by EDX. The evaluation of the antimicrobial and antifungal effects is linked to the use of a system provided by "locker sanitizer" equipment, which has been designed and built as part of this research, and is intended to treat textile garments by nebulizing the ZnO NP colloid (99.08 μg/mL) + UV-B, water + UV-B, and UV-B only, and also to evaluate the influence of the treatment time for 1, 2 and 3 min. In this sense, it is known that the nanomaterial used shows a better response to UV light because more hydroxyl radicals are produced, leading to a higher reaction rate, which results in greater efficiency in inhibitory processes. The results show that the use of the locker sanitizer is more efficient when using ZnO NP + UV-B light since it achieved 100 % growth inhibition against E. coli, C. albicans, and A. brasiliensis, and >99 % against S. aureus, after 3 min of treatment.

Comparative analysis of the insecticidal activity against Sitophilus oryzae (L.) and agro-morphological characteristics of maize using non-biogenic and biogenic ZnO nanoparticles

Utilizing environmentally friendly nanomaterials to address insect pests and promote plant growth is imperative.

Synergistic Anticandidal Effectiveness of Greenly Synthesized Zinc Oxide Nanoparticles with Antifungal Agents against Nosocomial Candidal Pathogens.

The high prevalence of fungal resistance to antifungal drugs necessitates finding new antifungal combinations to boost the antifungal bioactivity of these agents. Hence, the aim of the present investigation was to greenly synthesize zinc oxide nanoparticles (ZnO-NPs) using an aqueous leaf extract of Salvia officinalis and investigate their antifungal activity and synergistic efficiency with common antifungal agents. The biofabricated ZnO-NPs were characterized to detect their physicochemical properties. A disk diffusion assay was employed to investigate the antifungal effectiveness of the greenly synthesized ZnO-NPs and evaluate their synergistic patterns with common antifungal agents. The Candida tropicalis strain was detected to be the most susceptible strain to ZnO-NPs at both tested concentrations of 50 and 100 µg/disk, demonstrating relative suppressive zones of 19.68 ± 0.32 and 23.17 ± 0.45 mm, respectively. The minimum inhibitory concentration (MIC) of ZnO-NPs against the C. tropicalis strain was 40 µg/mL, whereas the minimum fungicidal concentration (MFC) was found to be 80 µg/mL. The highest synergistic efficiency of the biogenic ZnO-NPs with terbinafine antifungal agent was detected against the C. glabrata strain, whereas the highest synergistic efficiency was detected with fluconazole against the C. albicans strain, demonstrating relative increases in fold of inhibition area (IFA) values of 6.82 and 1.63, respectively. Moreover, potential synergistic efficiency was detected with the nystatin antifungal agent against the C. tropicalis strain with a relative IFA value of 1.06. The scanning electron microscopy (SEM) analysis affirmed the morphological deformations of candidal cells treated with the biosynthesized ZnO-NPs as the formation of abnormal infoldings of the cell wall and membranes and also the formation of pores in the cell wall and membranes, which might lead to the leakage of intracellular constituents. In conclusion, the potential synergistic efficiency of the biogenic ZnO-NPs with terbinafine, nystatin, and fluconazole against the tested candidal strains highlights the potential application of these combinations in formulating novel antifungal agents of high antimicrobial efficiency. The biogenic ZnO nanoparticles and antifungal drugs exhibit powerful synergistic efficiency, which highlights their prospective use in the formulation of efficient antimicrobial medications, including mouthwash, ointments, lotions, and creams for effective candidiasis treatment.

Biosynthesis and Antimicrobial Evaluation of Zinc Oxide Nanoparticles Using Chlorella vulgaris Biomass against Multidrug-Resistant Pathogens.

The rampant increase in antibiotic resistance has created a global barrier to the treatment of multidrug-resistant infections. Biogenic synthesis of nanomaterials is a novel approach to producing nanostructures with biological resources. Algae are known to be clean, nontoxic, cost-beneficial, and environmentally acceptable. Chlorella vulgaris is a popular microalga for its broad applications in food, supplements, pharmaceuticals, and cosmetics. In this study, we used Chlorella vulgaris biomass lyophilized powder as our green resource for the biosynthesis ZnONPs. Chlorella vulgaris culture was harvested at the end of the logarithmic phase, and the biomass was lyophilized. ZnONPs were synthesized using lyophilized biomass and 20 mM zinc acetate dihydrate at a temperature of 70 °C and continuous stirring in a water bath overnight. At the end of the reaction, UV-Vis absorption of colloidal suspension proved the synthesis of ZnONPs. The physicochemical characteristics of nanoparticles were analyzed using FTIR, DLS, TEM, and XRD. Based on FTIR spectra. The antibacterial activity of green synthesized nanostructures was evaluated against methicillin-resistant staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The synthesized ZnONPs have oxygen-containing groups on the surface that show the synthesized nanoparticles' stabilization. The Zeta potential was -27.4 mV, and the mean particle size was measured as 33.4 nanometers. Biogenic ZnONPs produced in this method have a notable size distribution and excellent surface energy, which can have vast applications like antimicrobial potential in pharmaceuticals as topical forms. Additionally, in order to evaluate the antimicrobial activity of ZnO nanoparticles, we used MRSA and VRE strains and the results showed the anti-MRSA activity at 400 and 625 μg mL-1, respectively. Thus, these biogenic ZnO nanoparticles revealed a substantial antibacterial effect against multidrug-resistant pathogens, associated with several serious systemic infections, and have the potential as an antimicrobial agent for further study.

Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview

Zinc oxide is a safe material for humans, with high biocompatibility and negligible cytotoxicity. Interestingly, it shows exceptional antimicrobial activity against bacteria, viruses, fungi, etc., especially when reduced to the nanometer size. As it is easily understandable, thanks to its properties, it is at the forefront of safe antimicrobials in this pandemic era. Besides, in the view of the 2022 European Green Deal announced by the European Commission, even science and nanotechnology are moving towards “greener” approaches to the synthesis of nanoparticles. Among them, biogenic ZnO nanoparticles have been extensively studied for their biological applications and environmental remediation. Plants, algae, fungi, yeast, etc., (which are composed of naturally occurring biomolecules) play, in biogenic processes, an active role in the formation of nanoparticles with distinct shapes and sizes. The present review targets the biogenic synthesis of ZnO nanoparticles, with a specific focus on their bioactive properties and antimicrobial application.

Novel synthesis of 3-(Phenyl) (ethylamino) methyl)-4-hydroxy-2H-chromen-2-one derivatives using biogenic ZnO nanoparticles and their applications

The present work describes the novel synthesis of 3, 3'-((phenyl) (ethylamino) methyl)-4-hydroxy-2H-chromen-2-one derivatives catalyzed by biogenic ZnO nanoparticles. The synthesized heterocyclic compounds were characterized by fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) andmass spectrometric techniques. Absorption, distribution, metabolism and excretion properties and various toxicities (ADMET) studies and in silico molecular docking studies were carried out for the synthesized compounds. The synthesized compounds were screened for their efficacy towards the antioxidant activity and were subjected to corrosion inhibition study towards the mild steel in acidic medium by weight loss method. Additionally, the recyclability of the employed catalyst was studied.

Biogenic ZnO Nanoparticles Synthesized from Origanum vulgare Abrogates Quorum Sensing and Biofilm Formation in Opportunistic Pathogen Chromobacterium violaceum.

This study presents an inexpensive, eco-friendly, and simple green synthesis of ZnO nanoparticles using Origanum vulgare extract. These nanoparticles are non-hazardous, environmentally friendly, and cheaper than other methods of biosynthesis. Ongoing research determines the role of phytochemicals in the fabrication and biosynthesis of ZnO NPs and their role in antibacterial activity and biomedical applications. Characterizations by fourier transform infrared spectroscopy (FTIR), diffuse reflectance UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) determine the successful biosynthesis of ZnO NPs. Meanwhile, TEM and X-ray diffraction studies approximated the spherical morphology and crystalline nature of biosynthesized ZnO NPs of nano size in the range of 20–30 nm. The global increase in drug resistance necessitates the search for new drugs with different mechanisms of action. Quorum sensing (QS), a cell-to-cell communication, has gained attention as an emerging drug target. It controls numerous biochemical processes in bacteria, which are essential for their survival and pathogenicity. The potential of nanomedicines has also been tested to synthesize new antibiotics to tackle drug resistance. ZnO NPs were explored for their antibacterial, antiquorum sensing, and antibiofilm activities with a bioreporter strain of Chromobacterium violaceum. Susceptibility testing results indicated the potential antibacterial activity of ZnO NPs with a minimum inhibitory concentration (MIC) of 4 µg/mL and minimum bactericidal concentration (MBC) of 16 µg/mL. Antiquorum-sensing assays revealed that these nanoparticles inhibit quorum sensing with minimum antiquorum sensing activity (MQSIC) of 1 µg/mL, without causing any bacterial growth inhibition. In addition, ZnO NPs inhibit biofilm formation at inhibitory and higher concentrations. RT-qPCR results supported the downregulation of the quorum sensing genes when C. violaceum was treated with ZnO NPs. The outcomes of this study are promising with regard to the biofilm and quorum sensing, emphasizing the potential applications of ZnO NPs against bacterial communication and biofilm formation.

Biogenic ZnO Nanoparticles Synthesized Using a Novel Plant Extract: Application to Enhance Physiological and Biochemical Traits in Maize.

The need to increase crop productivity and resistance directs interest in nanotechnology. Indeed, biogenic metal oxide nanoparticles can promote beneficial effects in plants, while their synthesis avoids the environmental impacts of conventional synthetic procedures. In this context, this research aimed to synthesize biogenic zinc oxide nanoparticles (ZnO-NPs) using, for the first time, an extract of a wild and spontaneous aquatic species, Lemna minor (duckweed). The effectiveness of this biogenic synthesis was evidenced for comparison with non-biogenic ZnO-NPs (obtained without using the plant extract), which have been synthesized in this research. XRD (X-ray diffraction), FE-SEM (field emission gun electron scanning microscopy), EDX (energy dispersive x-ray spectroscopy), TEM (transmission electron microscope) and UV-vis (ultraviolet-visible spectrophotometry) showed the biogenic approach effectiveness. The duckweed extract was subjected to UHPLC-ESI/QTOF-MS (ultra high-pressure liquid chromatography quadrupole time of flight mass spectrometry) phenolic profiling. This untargeted characterization highlighted a high and chemically diverse content in the duckweed extract of compounds potentially implicated in nanoparticulation. From an application standpoint, the effect of biogenic nanoparticles was investigated on some traits of maize subjected to seed priming with a wide range of biogenic ZnO-NPs concentrations. Inductive effects on the shoot and root biomass development were ascertained concerning the applied dosage. Furthermore, the biogenic ZnO-NPs stimulated the content of chlorophylls, carotenoids, and anthocyanin. Finally, the study of malondialdehyde content (MDA) as a marker of the oxidative status further highlighted the beneficial and positive action of the biogenic ZnO-NPs on maize.

Comparative efficacy of biogenic zinc oxide nanoparticles synthesized by Pseudochrobactrum sp. C5 and chemically synthesized zinc oxide nanoparticles for catalytic degradation of dyes and wastewater treatment.

Discharge of untreated textile wastewaters loaded with dyes is not only contaminating the soil and water resources but also posing a threat to the health and socioeconomic life of the people. Hence, there is a need to devise the strategies for effective treatment of such wastewaters. The present study reports the catalytic potential of biogenic ZnO nanoparticles (ZnO NPs) synthesized by using a bacterial strain Pseudochrobactrum sp. C5 for degradation of dyes and wastewater treatment. The catalytic potential of the biogenic ZnO NPs for degradation of dyes and wastewater treatment was also compared with that of the chemically synthesized ones. The characterization of the biogenic ZnO NPs through FT-IR, XRD, and field emission scanning electron microscopy (FESEM) indicated that these are granular agglomerated particles having a size range of 90-110nm and zeta potential of -27.41mV. These catalytic NPs had resulted into almost complete (> 90%) decolorization of various dyes including the methanol blue and reactive black 5. These NPs also resulted into a significant reduction in COD, TDS, EC, pH, and color of two real wastewaters spiked with reactive black 5 and reactive red 120. The findings of this study suggest that the biosynthesized ZnO NPs might serve as a potential green solution for treatment of dye-loaded textile wastewaters.

Biosynthesis of zinc oxide nanoparticles using leaf extracts of Alchornea laxiflora and its tyrosinase inhibition and catalytic studies

Zinc oxide nanoparticles (ZnO-NPs) were synthesized using a simple, low cost and safe method involving aqueous leaf extracts of Alchornea laxiflora and a zinc precursor salt. The nanoparticles were characterized by ultraviolet-visible (UV–vis), Fourier transform (FT-IR) spectroscopy, Energy dispersive X-ray (EDX), X-ray diffraction (XRD) and Scanning electron microscope (SEM). They were evaluated for their potentials as tyrosinase inhibitors and as catalysts in the degradation of Congo red dye. The UV–vis spectra gave characteristic surface Plasmon bands within the range 276−456 nm. The band gap energies of the ZnO-NPs were of the range, 2.50–3.67 ev. The SEM results showed average sizes of 29 nm and 38 nm for particles obtained using 1 mL and 2 mL of the plant extracts respectively. EDX plot showed the elemental compositions of the nanoparticles with zinc and oxygen being pronounced. The ZnO nanoparticles exhibited good photocatalytic efficiency of 87 % degradation of Congo red (CR) dye molecules in 60 min, They also showed good anti-tyrosinase ability with an IC50 of 66.28 μg/mL. Overall the biogenic ZnO nanoparticles are promising materials for dual applications as photocatalysts in the degradation of Congo red dye and as tyrosinase inhibitors.

Biomedical Applications of Biogenic Zinc Oxide Nanoparticles Manufactured from Leaf Extracts of Calotropis gigantea (L.) Dryand.

Green synthesis has made us an exciting approach in the field of nanotechnology. Biogenic zinc oxide nanoparticles (ZnONPs) were synthesized using leaf extracts of Calotropis gigantea (L.) Dryand. in the presence of zinc nitrate hexahydrate as a precursor molecule. ZnONPs were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD) patterns, and Fourier transform infrared spectroscopy (FT-IR) analysis and further in understanding the biomedical applications of antimicrobial (minimum inhibitory concentration method) and anticancer (apoptosis assay) activities, cytology (flow cytometry) and cytotoxicity (% cell viability), deoxyribonucleic acid (DNA) fragmentation (reverse transcriptase polymerase chain reaction (RT-PCR)), and caspase assay (polymerase chain reactions (PCR)) studies. The morphology of nanoparticles was determined by SEM analysis. XRD pattern showed the value of highest peak of 36.15° with 101 plane region among the ten recorded peaks. FTIR spectrum indicated stretching vibration of O-H at 3441.77 cm−1. The antibacterial activity of biogenic ZnO nanoparticles was studied against human pathogenic bacteria—Campylobacter jejuni ATCC 29428 and Neisseria gonorrhoeae ATCC 49226—and showed 50% zone of inhibition. A cytotoxic study against the breast cancer cell lines of MDAMB-231 revealed that the ZnONPs as a good anticancer agent could be sliced by all existing and metabolically active cells. Biosynthesized ZnONPs potentially alter the apoptotic protein expression and trigger apoptosis in the MDAMB-231 cells. Therefore, the biogenic ZnO nanoparticles would be useful and have the great potential in the field of biomedical applications.

Synthesis of biogenic ZnO nanoparticles and its impact on seed germination and root growth of Oryza sativa L. and Vigna unguiculata L

Zinc oxide nanoparticles (ZnO NPs) were synthesised using a typical green route employing bioderived structure directing agents in aqueous medium over circum neutral pH conditions. The microstructure and morphology of the nanoparticles were characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM). Hybrid nature of the citric acid-ZnO NPs were characterized by FT-IR spectroscopy and Uv-vis spectroscopy. The growth impact of millimolar concentrations of these colloidal nanoparticle dispersions on Oryza sativa L. (rice) and Vigna unguiculata L. (pea) plants were also analysed with regard to parameters such as germination index and root growth.

Seaweed-Based Biogenic ZnO Nanoparticles for Improving Agro-morphological Characteristics of Rice (Oryza sativa L.)

To develop sustainable nano-agriculture, biogenic ZnO nanoparticles have been prepared using brown seaweed Turbinaria ornata (T. ornata) extract as a priming agent to promote rice seed quality and crop yield attributing to rice seeds. The results of various physico-chemical characterization analysis indicate the formation of ZnO nanoparticles. Rice seeds primed with seaweed-based biogenic ZnO nanoparticles at 10 mg/L showed that there has been enhancement in the seed germination (100%), shoot length (100 mm), shoot width (1.0 mm), root length (185.0 mm) root width (0.5 mm), seedling length (216 mm), leaf length 33.0 mm), leaf width (2.0 mm), seedling vigor (28,500 vigor index) and dry matter production (DMP) compared to the conventional hydropriming. Consequently, a micro-plot experiment has been conducted with foliar application of biogenic ZnO nanoparticles and the results revealed that at 10 mg/L recorded improvement in grain weight (653 g/m2), seed length (8.0 mm), seed thickness (1.71 mm) and seed width (3.23 mm) compared to hydroprimed seeds under. HR-SEM micrograph confirms the presence and assimilation of biogenic ZnO nanoparticles in treated seed/foliar applied leaf of rice plant. Further, ICP-MS analysis also confirmed the increase in Zn content in the nanoprimed rice seedlings and foliar applied rice crop in a dose-dependent manner. The experimental results thus demonstrate that the application of seaweed biogenic ZnO nanoparticles improving agronomical characteristics of rice.

Biogenic ZnO nanoparticles: a study of blueshift of optical band gap and photocatalytic degradation of reactive yellow 186 dye under direct sunlight

Abstract Synthesis of nanoparticles (NPs) using plant extracts has been suggested as an environmentally friendly alternative to chemical synthesis of semiconductor NPs. In the present study, ZnO NPs were synthesized by a simple and cost-effective method using Coriandrum sativum leaf extract and zinc acetate as precursors. The as-synthesized ZnO NPs were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analysis. The results confirmed the formation of ZnO NPs with a wurtzite structure, spherical shape and average particle size of 24 nm. The photocatalytic degradation of reactive yellow 186 (RY 186) dye was carried out under direct sunlight irradiation and its degradation efficiency and apparent rate constant (K’app) of reaction were calculated to be 93.38%, and 0.0019 min−1, respectively. The optical band gap value of the as-synthesized ZnO NPs was found to be 3.4 eV, which indicates the presence of blueshift. Owing to the presence of blueshift and a wide band gap of synthesized biogenic ZnO NPs, the overall absorption of sunlight irradiation will be enhanced, which leads to higher degradation efficiency of the dye. The current study thus highlights the optical band gap properties of biogenic ZnO NPs and their significance as a heterogeneous catalyst for the purification of polluted water.