Synthesis Of Gold Nanoparticles Research Articles

Structural and antimicrobial properties of synthesized gold nanoparticles using biological and chemical approaches

This study explores the synthesis and characterization of gold nanoparticles (AuNPs) using green and chemical methods, employing ginger extract and curcumin as reducing agents, in comparison to sodium citrate reduction. The biosynthesized AuNPs synthesized with ginger extract exhibited an average hydrodynamic diameter of 15 and 10 nm for curcumin-conjugated AuNPs, while chemically synthesized AuNPs with sodium citrate displayed an average size of 10 nm. Assessments via Zeta potential measurements revealed negative surface charges across all samples, with the curcumin-conjugated AuNPs showing −36.3 mV, ginger extract-synthesized AuNPs showing −31.7 mV, and chemically produced gold nanoparticles having a surface charge of −40.4 mV. Transmission Electron Microscopy (TEM) confirmed spherical morphologies for the synthesized nanoparticles,and it revealed the presence of biomolecules embedded within the nanoparticles synthesized using biological materials, whereas chemically synthesized AuNPs lacked such features. The FTIR spectra of the biosynthesized AuNPs highlighted the presence of phenolic and aromatic compounds from the ginger extract and curcumin, indicating their role in coating the nanoparticles. Gas chromatography-mass spectrometry (GC-MS) analysis identified gingerol as a key component in the ginger extract, contributing to nanoparticle capping. The antimicrobial efficacy of the AuNPs was evaluated against P. aeruginosa, E. coli, and S. aureus, revealing superior activity for curcumin-AuNPs, with ginger-AuNPs also outperforming chemically synthesized counterparts. These findings confirm the advantages of biological approaches, using a plant extract like ginger and pure curcumin suspension, for better size distribution when used as reducing agents, along with improved antimicrobial efficacy compared to chemically produced gold nanoparticles synthesized with sodium citrate. This study also highlight the potential of green-synthesized AuNPs in biomedical applications, due to their enhanced stability from higher surface charge and the repeatability of biological methods.

Biosynthesis of gold and silver nanoparticle using water hyacinth (Eichhornia crassipes) extract for photocatalytic degradation of organophosphate and organochlorine pesticide

The study aimed to assess the efficiency of synthesized gold (Au) and silver (Ag) nanoparticles in the degradation of organochlorine and organophosphate pesticides through photocatalysis. The synthesis of gold and silver nanoparticles was achieved using Eichhornia crassipes (water hyacinth extract). Photocatalytic degradation tests were conducted on organochlorine and organophosphate pesticides using gold and silver nanoparticles, with the absorbance of the samples measured by a UV spectrophotometer. The photocatalytic degradation rates of organochlorine and organophosphate were determined, with varied concentrations of the synthesized nanoparticles. The results showed high degradation rates at lower concentrations (10–20 ppm), with degradations of 51.789%, 47.954%, 47.983%, 44.088%, 41.565%, and 36.749% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. The results also revealed that higher degradation rates were observed at longer reaction times (70–80 minutes), with percentage degradations of 44.344% and 49.987%, 41.754% and 45.937%, 36.773% and 40.458% for 25/75, 50/50, and 75/25 Au nanoparticle ratios, respectively. Lower degradation efficiencies were observed at shorter reaction times (10–20 minutes), with percentage degradations of 15.356% and 19.982%, 13.746% and 17.082%, and 10.976% and 15.167% for 25/75, 50/50, and 75/25 ratios, respectively. Additionally, the results showed high degradation rates at lower concentrations (10–20 ppm) for Ag nanoparticles, with percentage degradations ranging from 40.814% to 44.822% across AgNP ratios (25/75, 50/50, 75/25), indicating efficient degradation at lower concentrations. Conversely, at higher concentrations (60–80 ppm), the degradation efficiency was notably lower, with percentage degradations ranging from 7.004% to 13.539% across different AgNP ratios. In conclusion, Au nanoparticles exhibited higher photocatalytic efficiency than Ag nanoparticles, particularly in degrading organophosphate (Sniper) pesticides. It is recommended that these synthesized nanoparticles be considered as environmentally friendly and cost-effective options for pesticide degradation.

Expanding Chemical Space in the Synthesis of Gold Bipyramids.

Gold bipyramids (AuBPs), despite having superior properties compared to their spectroscopically similar counterparts, gold nanorods, have found comparatively limited applications. This discrepancy is primarily due to the lack of protocols to tailor their dimensions. Typically, the concentration of Au seeds is virtually the sole factor that determines the aspect ratio and thus, the optical properties of AuBPs. As a result, varying the volumes of AuBPs while incurring minimal changes to their optical spectra remains a synthetically non-trivial task. Here, the chemical space in the seeded growth of AuBPs, is expanded by exploiting the interplay between bromide, silver ions, and seed concentration for tuning the final dimensions and optical properties of AuBPs. Specifically, a 6 fold change in volumes of AuBPs is achieved while maintaining the fixed plasmon band position. Further overgrowth of as-prepared bipyramids broadens the realizable dimensions without compromising quality and initial morphology. Overall, the results expand the chemical toolbox in the wet-chemistry synthesis of anisotropic gold nanoparticles, which is relevant for health, colorimetric sensors, and energy applications.

Difference in the Catalytic Activity of Atoms in the Corners and at the Edges of Gold Nanoparticles: Hydrogen Isotope Exchange Reaction

The goal of this work is to investigate the catalytic activities of low-coordination atoms located in gold nanoparticles. Gold nanoparticles with sizes from 0.7 to 40 nm deposited on γ-Al2O3 were used as a catalyst. Synthesized gold nanoparticles and prepared catalysts were characterized by HRTEM, SEM, XRD, DLS, and UV-Vis spectroscopy. The specific activity of gold nanoparticles towards the isotope exchange reaction at 77 K was studied as a function of nanoparticle size. The catalytic activity increases significantly when the particle size is less than 3 nm. The activities of low-coordination gold atoms located at the edges and in the corners are markedly different. Corner atoms (CN = 6) are more than 40 times more active in the reaction of hydrogen isotope exchange than edge atoms (CN = 7). TOF for atoms with coordination numbers CN = 6 and CN = 7 are 0.258 ± 0.020 and 0.006 ± 0.001 molecules site−1 s−1, respectively. An equation was proposed for the dependence of the catalytic activity of the reaction on the particle size, the number of atoms on the surface, and their activity.

Lights on the Synthesis of Surfactant-Free Colloidal Gold Nanoparticles in Alkaline Mixtures of Alcohols and Water.

Surfactant-free colloidal syntheses in aqueous media are attractive to develop nanomaterials relevant for various applications, e. g. catalysis or medicine. However, controlled green syntheses without surfactants of metal nanoparticles in aqueous media remain scarce. Here, room temperature syntheses of gold (Au) nanoparticles (NPs) that require only HAuCl4, alkaline water and an alcohol, i. e. relatively benign chemicals and mild reaction conditions, are developed. The findings of a comprehensive multi-parameters screening performed in small volumes (<3 mL) over 1000+ experiments pave the way to greener high throughput screenings of large parametric spaces and lead to scalable (100 mL) synthetic strategies. A rational selection of the alcohol is proposed. The influence of lights with defined wavelengths (222-690 nm) is investigated. It is found that lights with lower wavelengths favor the formation of smaller 5 nm NPs. Different kinetics and formation pathways are observed for different alcohols and for lights with different wavelengths. The sensitivity to various experimental parameters increases with the alcohol used in the order glycerol<ethylene glycol<ethanol<methanol. New strategies for a rational fine size control, and to some extend shape control, are identified. The results lead to more sustainable and reproducible surfactant-free colloidal syntheses of NPs.

Gold Nanoparticles Stabilized by δ‐Cyclodextrin in Aqueous Media: Characterization and Evaluation of their Catalytic Properties in the Reduction of 4‐Nitrophenol

AbstractThe synthesis of gold nanoparticles stabilized by cyclomaltononaose (δ‐CD) in aqueous phase was performed. Protection of the gold nanoparticles by standard native cyclodextrins such as α‐CD, β‐CD and γ‐CD has also been considered for comparison. All of these colloidal suspensions were fully characterized by FT‐IR, DLS, UV‐Vis spectroscopy, TEM, XPS and also NMR experiments. Finally, their catalytic activity was evaluated in the reduction of 4‐nitrophenol to 4‐aminophenol in the presence of an excess of sodium borohydride. Gold nanoparticles stabilized by δ‐CD presented good activity and exhibited better long‐term stability. This study highlighted the fact that the obtention of the best catalytic activity corresponds to not only a compromise between the size of the nanoparticles and the interaction of the substrate with the metal nanoparticles surface, but also the supramolecular interactions between the substrate and the cyclodextrin.

A highly sensitive and selective label-free impedimetric immunosensor for the detection of interleukin-6 based on AuNPs@pDA@NiCo2S4@MoS2 nanocomposite.

A highly sensitive and selective label-free impedimetric immunosensor based on AuNPs@pDA@NiCo2S4@MoS2 nanocomposite modified on the surface of a screen-printed electrode (SPE) was designed for the detection of interleukin-6 (IL-6). The distribution of NiCo2S4 nanoparticles on MoS2 nanosheets was able to prevent them from agglomerating. The polydopamine (pDA) layer was coated on the surface of NiCo2S4@MoS2 nanosheets by self-polymerization, which improved the stability and biocompatibility of the nanomaterial. The excellent reduction ability of pDA promoted the synthesis of gold nanoparticles (AuNPs), which increased the amount of antibody adsorption and the conductivity of the material. Finally, the antibody (Ab) of IL-6 was immobilized on the surface of AuNPs@pDA@NiCo2S4@MoS2 nanocomposite. Electrochemical impedance spectroscopy (EIS) was used to detect the change of impedance before and after the immune response between Ab and IL-6 antigen (IL-6). Under the optimal experimental conditions, the relative change in impedance and the logarithmic concentration of IL-6 showed a good linear relationship in the range 1.00 to 1.00 × 106pg/mL, with a low detection limit of 0.97pg/mL. In addition, the proposed immunosensor performed with good reproducibility, stability, and specificity. It was successfully applied to the determination of IL-6 in patient's serum samples of head and neck carcinoma with recoveries of 98.40% to 106.5%. To sum up, the proposed label-free impedimetric immunosensor was successfully constructed for IL-6 detection in real samples.

Green synthesis of Gold Nanoparticles by using Nymphaea stellata: in-vitro Evaluation against Hepatic Cancer Cells

Green synthesis of Gold Nanoparticles by using Nymphaea stellata: in-vitro Evaluation against Hepatic Cancer Cells

A New Tropical Wild Fern for the Green Synthesis of Gold Nanoparticles: Comprehensive Characterization and Application in Water Treatment

Utilizing natural plant extracts to synthesize of gold nanoparticles (AuNPs) has emerged as a sustainable and eco-friendly alternative to conventional methods. Nephrolepis biserrata (NB), a tropical perennial fern, is rich in bioactive phytochemicals such as alkaloids, tannins, and flavonoids, which can effectively serve as reducing and stabilizing agents in the green synthesis of AuNPs. UV-visual spectrophotometry was employed to optimize synthesis parameters, including the reactant ratio of chloroauric acid (HAuCl₄) to NB, HAuCl₄ concentration, and reaction temperature. Optimal AuNP synthesis was achieved at a 1:0.25 HAuCl₄ ratio, a concentration of 0.25 mM HAuCl₄, and a reaction temperature of 70 °C, yielding nanoparticles with an absorbance of 1.449 ± 0.039 at a λmax of 531 nm. The synthesized AuNPs were characterized using FTIR, Zeta potential, FESEM/EDX, and XRD analyses. FTIR results indicated that the hydroxyl (O–H) and carbonyl (C=O) groups in NB facilitated the reduction of Au³⁺ ions. Zeta potential measurements confirmed AuNPs’ stability at -15.1 mV. The FE-SEM images and EDX analysis verified that the AuNPs were predominantly spherical, with minimal variation in shape. The average particle size was measured to be 28.184 ± 7.87 nm. The EDX spectrum showed strong signals for atomic gold at 2.12 and 2.14 keV, indicating that gold constituted approximately 48.49% of the sample by weight, which can be attributed to the bio-reductants in the plant extracts.The peaks in the X-ray diffractogram that correspond to Bragg’s reflection values of 38°, 44°, 64°, and 77° at 2θ indicate the formation of the face-centered cubic crystalline structure of AuNPs. These nanoparticles demonstrated high catalytic efficiency in the degradation of methylene blue (MB) dye, following a pseudo-first-order reaction in the presence of NaBH₄. These findings suggest that NB-mediated AuNPs offer a promising and eco-friendly approach for catalytic applications in wastewater treatment.

Eco-Friendly Synthesis of Gold Nanoparticles via Tangerine Peel Extract: Unveiling Their Multifaceted Biological and Catalytic Potentials

Eco-Friendly Synthesis of Gold Nanoparticles via Tangerine Peel Extract: Unveiling Their Multifaceted Biological and Catalytic Potentials

Capping agent-free aqueous gold nanoparticles generated by an environmentally friendly plasma-liquid method

This study investigates a simple approach for synthesizing gold nanoparticles (Au NPs) using atmospheric pressure plasma without the need for reducing agents, additives, or capping agents. The size, morphology, optical properties, and aggregation stability of the synthesized Au NPs were characterized using scanning electron microscopy, UV-vis spectroscopy, and zeta potential analysis. The UV-vis absorption spectra of the gold nanoparticles, obtained at various Au3+ concentrations and treatment durations with anode plasma discharge, were analyzed. The UV-vis spectra revealed a surface plasmon resonance absorption band between 530–600 nm, indicative of Au NP formation. Results demonstrated that the size of Au NPs can be tuned within the range of 30–75 nm by adjusting the gold salt precursor concentration from 0.3 to 2.5 mmol/L. It was found that plasma treatment for 3–10 minutes, at different Au3+ concentrations, resulted in the formation of Au NPs with varying sizes and morphologies. The study showed that particles with different shapes – spherical, hexagonal, and triangular – were formed depending on the initial concentration of Au3+. The plasma-chemically synthesized nanoparticles at an Au3+ concentration of 0.06 mmol/L were predominantly spherical and exhibited the highest stability (lasting 12–24 hours), with a zeta potential of –20 to –22 mV, compared to samples with Au3+ concentrations ranging from 0.3 to 2.5 mmol/L.

Biogenically synthesized gold nanocarrier ameliorated antiproliferative and apoptotic efficacy of doxorubicin against lung cancer.

Conventional chemotherapy treatment is commonly linked to significant side effects due to high therapeutic doses. In this regard, nanoformulations with chemotherapeutic medications hold promise in enhancing drug effectiveness through the reduction of therapeutic dosages, thereby mitigating the potential for adverse side effects. Because of numerous applications in the biomedical arena, there has been a rising interest in developing an environmentally acceptable, long-lasting, and affordable technique for the production of gold nanoparticles. In this particular context, the incorporation of plant extracts in the production of metallic nanoparticles has garnered the interest of numerous scholars. Here, we report the synthesis of gold particles by the green method using Cannabis sativa L. leaf extract and their conjugation with doxorubicin. The gold nanoparticles were synthesized by using Cannabis sativa extract and were characterized with various biophysical techniques. Subsequently, gold nanoparticles were conjugated with doxorubicin and their efficacy was tested on A549 cells. The biogenic synthesis of gold nanoparticles was ascertained through an absorption peak at a wavelength of 524nm, and it was shifted to 527nm when conjugated with doxorubicin. Nanoparticles were found to be stable exhibiting a zeta potential value of -20.1mV, and it changed to -12.7mV when loaded with doxorubicin. The hydrodynamic diameter of nanoparticles was determined to be 45.64nm and it was increased to 58.95nm when conjugated with the drug. The average size of nanoparticles analyzed by TEM was found to be approximately 17.2nm, while it was 23.5nm in the case of drug-nanoconjugate. Moreover, there was a significant amelioration in the antiproliferative potential of doxorubicin against lung cancer A549 cells when delivered with gold nanocarrier, which was evident by the lower IC50 and IC75 values of drug-nanoconjugates in comparison to drug alone. Furthermore, the inhibitory effect of drug-nanoconjugates and drug alone was characterized by alteration in the cell morphology, nuclear condensation, increased production of reactive oxygen species, abrogation of mitochondrial membrane potential, and enhanced caspase activities in A549 cells. In sum, our results suggested enhanced efficacy of doxorubicin-gold nanoconjugates, indicating effective delivery of doxorubicin inside the cell by gold nanoparticles.

One-pot synthesis of chiral cysteine-capped gold nanoparticles for use as vaccine adjuvants in mice

The influence of chirality on the biological activity of nanoparticles, including their interaction with the immune system, is a growing area of interest. This study presents a one-pot synthesis method for 15 nm L-cysteine or D-cysteine capped gold nanoparticles (L/D-Cys-GNPs) and evaluates their immunological potential as adjuvants in mice. The synthesized GNPs were comprehensively characterized using UV–visible absorption spectroscopy, FTIR, CD spectra, and TEM, revealing enhanced stability and effective internalization by human umbilical vein endothelial cells (HUVEC), with L-Cys-GNPs exhibiting a higher uptake rate. In vivo immunization studies demonstrated that L-Cys-GNPs significantly boosted the production of anti-ovalbumin(OVA) IgG antibodies compared to D-Cys-GNPs (>66 folds), underscoring the importance of chiral surface properties in modulating immune responses. However, the encapsulation of GNPs in liposomes negated the chiral effect, suggesting that delivery methods may influence the interaction of GNPs with the immune system. The findings highlight the role of chirality in vaccine development and provide insights into targeted antigen delivery systems. This work contributes to the understanding of chirality in vaccine development and paves the way for the design of more effective vaccines against challenging diseases.

SERS Sensor for Acetylcholine Detection Based on Covalent Organic Framework Hybridized Gold Nanoparticles As Nanozymes.

An innovative and potent nanozyme with reductase-like activity was developed by integrating the in situ synthesis of gold nanoparticles (Au NPs) onto the surface of a covalent organic framework (COF). Based on the reductase-like activity of the COF-hybridized Au NPs, this nanozyme could efficiently catalyze the reduction of 4-nitrophenol (4-NPH). Moreover, the prepared nanohybrid was utilized as an excellent surface-enhanced Raman scattering (SERS) substrate for highly sensitive SERS detection by combining the excellent adsorption properties of COFs and the large number of Raman hotspots between the high-density Au NPs. For the first time, 4-NPH was used as an SERS marker to detect the electron receptor acetylcholine (Ach), with high sensitivity; Ach acted as an inhibitor in this catalytic reaction. The linear range of Ach was 1.0 pM to 10 nM, the correlation coefficient was 0.993, the detection limit was approximately 0.3 pM with a signal-to-noise ratio (s/n) of 3, and the acceptable recovery in the serum was 97.2% to 104.5%. The results from this study show that the nanozyme-SERS system has great potential for chemical and bioassay applications.

Microwave-Based Rapid Green Synthesis of Gold Nanoparticles Utilizing a Notorious Weed (Mikania micrantha) Extract and Evaluation of their Biomedical Properties

Microwave-Based Rapid Green Synthesis of Gold Nanoparticles Utilizing a Notorious Weed (Mikania micrantha) Extract and Evaluation of their Biomedical Properties

Exploring the anticancer and antioxidant potential of gold nanoparticles synthesized from Pterocarpus marsupium bark extract against oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a disease of significant concern with higher mortality rates. Conventional treatment approaches have several drawbacks, leading to the opening of new research avenues in the field of nanoparticle-based cancer therapeutics. The study aimed at the synthesis of gold nanoparticles (Pm-AuNPs) from the aqueous bark extract of Pterocarpus marsupium, followed by its characterization and in vitro anticancer evaluation against OSCC. The synthesized Pm-AuNPs were characterized using UV–visible spectroscopy, particle size analyser, zeta potential, FTIR and SEM techniques. The anticancer potential of the Pm-AuNPs was evaluated against OSCC cell lines (SCC29b, SSC154 and OECM-1) through in vitro assays. The IC50 value was found to be 25 ± 1.2, 45 ± 1.5 and 75 ± 2.1 µg/mL for the three OSCC cell lines, elucidating Pm-AuNPs cytotoxic effects and mechanism of action. Intracellular ROS and SOX detection, mitochondrial transmembrane potential analysis and apoptosis detection were used to confirm the activity of Pm-AuNPs against OSCC. Acute toxicity studies on Wistar rats confirmed the non-toxic nature of the Pm-AuNPs at a higher dose concentration up to 2000 mg/kg body weight. The findings underscore Pm-AuNPs as promising candidates for future anticancer therapeutics, providing insights into their mechanism of action and therapeutic efficacy against OSCC.

Processable Circularly Polarized Luminescence for the Synthesis of Chiral Plasmonic Nanoparticles

AbstractCircularly polarized light is previously shown as a chiral bias to enable the synthesis of chiral plasmonic nanomaterials through light‐matter interactions. The traditional approach for circularly polarized light generation relies on a “top‐down” approach by removing undesired light polarization through optics, which suffers from energy loss and compatibility issues. An alternative approach is to develop chiral phosphors that emit efficient circularly polarized luminescence (CPL). However, most materials fail to produce processable CPL with both high quantum yield and dissymmetry factors, let alone the synthesis of chiral nanomaterials. Herein, a liquid‐crystal‐templated framework is developed to assemble halide perovskite nanocrystals, CsPbX3 (X = Cl, Br, I), and achieved efficient CPL with the record‐high figure of merit (FM) for three primary colors (Red, Green, Blue). The fidelity of the CPL is further demonstrated in the synthesis of chiral gold nanoparticles, where a five‐fold increase in optical activity is achieved.

Particle size and band gap evaluation of green gold nanoparticles (AuNPs) with potential applications

Abstract The present study was aimed towards green synthesis of gold nanoparticles (AuNPs) using fungal strain (SGSK-7) with assessment of their size using different techniques viz., X-ray diffractormeter, Dynamic light scattering, Atomic force microscopy, FE-Scanning Electron Microscopy and Fourier transform Infrared Spectroscopy. The intense characteristic diffraction peaks at angle 2Ѳ (38.13˚) presented the crystalline nature of the reduced gold solution and calculation of crystalline size (12 nm) using Scherer’s equation further confirmed synthesis of gold nanoparticles while dynamic light scattering analysis indicated the particle size range of gold nanoparticles between 2 nm to 50 nm. Field Emission Scanning Electron Microscopic (FESEM) and Atomic Force Microscopy (AFM) analysis of extracellular gold nanoparticles depicts spherical shape of AuNPs of approximately 40 nm. Fourier transform Infrared (FTIR) Spectroscopy depicted the presence of the gold nanoparticles along with the other biomolecules secreted by fungus which plays vital role in reduction, capping and stabilization of gold nanoparticles. Energy dispersive X-ray, mapping analysis, Zeta potential and UV-Vis spectrophotometery analysis further confirmed the presence and stability of gold nanoparticles, respectively. Zeta potential of gold nanoparticles leads to conclude the neutral nature (-10 mV to 10mV) of the particles. The UV-Visible spectrophotometeric analysis also confirmed the formation of gold nanoparticles with an absorption peak at 547 nm. On the basis of UV-Visible spectra the optical band gap of 2.44 eV is examined. The phylogenetic relatedness of SGSK-7 revealed 99% homology with Aspergillus tamari after sequencing of the ITS region followed by BLAST.

Synthesis of gold nanoparticles using soybean byproducts: applications in catalysis

AbstractThis study demonstrates the feasibility of extracting lecithin from oil industry byproducts in an eco‐friendly manner, with minimal use of water and without harmful chemicals. Liposomes can be generated directly from this extracted lecithin, enhancing the value of these byproducts and enabling the production of catalytic gold nanoparticles (AuNPs). Thin‐layer chromatography of the extracted lecithin revealed a phospholipid composition primarily consisting of phosphatidylethanolamine and phosphatidylcholine, and surface tension studies demonstrated similar behavior between the extracted and commercial lecithin. Liposome formation using sustainable lecithin (LPn) resulted in structures that were stable for at least 10 days, exhibiting a low polydispersity index (0.395) and uniform size (approximately 214 ± 7 nm). Gold nanoparticles were synthesized successfully in LPn loaded with [HAuCl4] by using different photoreduction methods: ultraviolet (UV) lamp, pulsed laser 355 nm, and sunlight irradiation. The AuNPs exhibited characteristic sizes (ranging from 5.03 to 6.78 nm) and optical properties typical of nanoparticles, including a distinct surface plasmon resonance. As a proof of concept, we also demonstrated that the synthesized AuNPs exhibited catalytic activity in UV‐induced cis‐trans isomerization reactions. Overall, the study highlights the potential of sustainable soy lecithin extraction for diverse applications, including nanoparticle synthesis and catalysis.

Eco-friendly Synthesis of Gold Nanoparticles of Methanolic Extract of Bauhinia vahlii Leaves and Evaluation of Tyrosinase Inhibitory Activity

Background: The green synthesis of gold nanoparticles (AuNPs) using natural materials has gained significant attention in recent years due to their eco-friendliness and potential applications in various fields. Methods: The present study aimed at the green synthesis and anti-hyperpigmentation potential of gold nanoparticles (AuNPs) using a methanolic extract of Bauhinia vahlii. Furthermore, the green synthesis of the AuNPs was confirmed by UV-visible, FT-IR, XRD, and EMDEX analysis. The size and surface topological significance of green synthesized AuNPs were evaluated through Scanning Electron Microscope and Field Emission Scanning Electron Microscopy. Results: The size of the synthesized AuNPs was found to be in the range of 100-1000 nm. The tyrosinase inhibitory activity of AuNPs was evaluated through the mushroom tyrosinase inhibitory assay method. The tyrosinase inhibitory activities of crude extract, AuNPs, and Kojic acid were found to be 98.7 ±0.7, 75±1.3 and 41±1.1 μg/ml, respectively. Conclusion: Hence, green synthesized AuNPs of B. vahlii leaf extract may be used as a potent antihyperpigmentation agent in the market of nano cosmeceuticals.