Functionalized Silver Nanoparticles Research Articles

Synthesis and Characterization of Thymol Carbon Nanodot Functionalized Silver Nanoparticles (ThCND-AgNPs) and Evaluation of Their Antiproliferative, Anti-Invasive, and Apoptotic Effects on OVCAR-3 Ovarian Cancer Cells.

Ovarian cancer belongs to the category of gynecological malignancies and unfortunately holds the distinction of being the most aggressive among them. It is ranked as the fifth highest cause of cancer-related deaths in women worldwide. The utilization of metal nanoparticles (NPs) linked with natural herbal molecules in biomedical applications has been on the rise. Thymol carbon nanodot functionalized silver nanoparticles (ThCND-AgNPs) were synthesized in an original manner and subjected to thorough characterization, including analysis of their size, morphology, and elemental composition. The aim of this study is to investigate the effects of the ThCND-AgNPs on cell proliferation, invasion, and apoptotic gene expressions in OVCAR-3 ovarian cancer cells. The effect of ThCND-AgNPs on cell viability in OVCAR cells was determined in a dose- and time-dependent manner using the XTT method. The effect on the expression changes of apoptotic-related genes was assessed through the Real-time PCR method, while the anti-invasive activity was measured using the matrigel invasion chamber assay. The ThCND-AgNP molecule exhibited a dose- and time-dependent reduction in cell proliferation in OVCAR-3 cells. The IC50 values were determined to be 388.53 μg/mL at 24 h and 145.683 μg/mL at 48 h. Furthermore, the molecule was found to reduce cell invasion by 51.12% compared with the control group in OVCAR-3 cells. In terms of apoptotic-related genes, Bcl-2 expression was downregulated, while BAX, CASPASE-3, -8, and -9 expressions were unregulated. In conclusion, the obtained data reveal the potential antiproliferative, apoptotic, and anti-invasive effects of our original ThCND-AgNP molecule in ovarian cancer. While these results need further confirmation through more detailed experiments, they will provide insights for future studies.

Smartphone-integrated inkjet-printed paper sensor and UV/Vis spectrophotometric method for on-site detection of As3+ and L-cysteine in food samples using novel AMTPP-functionalized silver nanoparticles

The increasing prevalence of arsenic (As3+) in water and its health impacts necessitate advanced detection methods. Similarly, monitoring L-Cysteine, a vital thiol-containing amino acid, is crucial for assessing physiological processes and disorders. This study presents a novel method for detecting As3+ and L-Cysteine in food samples using 4-amino-3-(D-galactopentitol-1-yl)-5-mercapto-1,2,4-triazole (AMTPP) functionalized silver nanoparticles (AMTPP-AgNPs) by UV/Vis spectrophotometric method and smartphone-assisted inkjet-printed paper-based sensors. AMTPP-AgNPs, synthesized through a detailed process, show exceptional selectivity and sensitivity to As3+ and L-Cysteine, undisturbed by other metal ions and amino acids. Characterization techniques like FTIR, DLS, Zeta Potential, AFM, and SEM detailed their morphological and interaction properties. Optimizing detection parameters, such as response time, pH, and temperature, improved sensitivity and achieved low detection limits. The limits of detection (LODs) were 0.0052 μM for L-cysteine and 0.0092 μM for As3+, as calculated using UV–Vis spectrophotometric methods. The method also demonstrated high recovery rates in spiked meat and corn samples. This research offers a cost-effective, rapid method for on-site food analysis, significantly aiding environmental and public health monitoring.

A rapid colorimetric sensor for the detection of mercury in environmental samples employing 2 aminobenzohydrazide schiff base functionalized silver nanoparticles

Mercury (Hg2+) is an extremely toxic and dangerous element for living organisms. Herein, a simple and selective sensor based on the Schiff base of 2-aminobenzohydrazide with triazole thiazole substituted vanillin (EAHT) functionalized silver nanoparticles (EAHT-AgNPs) is proposed for the detection of Hg2+ in environmental water samples. The chemical reduction method was employed to synthesize EAHT-AgNPs using sodium borohydride as the reducing agent. The synthesized nanoparticles were initially confirmed by UV-visible and FTIR spectroscopy, followed by analysis with a zeta sizer to determine their average size, surface charge and polydispersity index. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) were employed to determine the size and morphology of EAHT-AgNPs. Additionally, the functionalized particles exhibited stability at varying pH values, salinity concentrations and elevated temperature. The addition of Hg2+ altered the yellow color of EAHT-AgNPs to colorless, confirming the complex formation. The analytical response constructed as a decrease in absorbance versus concentration showed linearity (R2 = 0. 991) from 0.1 to 100 µM with a limit of detection of 0.04 µM (40 nM) and limit of quantification of 0.085 µM (85 nM). The sensor was successfully applied for the detection of Hg2+ ions in tap water. In conclusion, Schiff base of 2-aminobenzohydrozide with triazole thiazole substituted vanillin silver nanoparticle-based chemosensor is highly sensitive and selective for the detection of Hg2+ in water samples. The proposed sensor has been applied for mercury detection tap water, future research should explore its applications in more complex samples like industrial wastewater and marine environments. Further, studies may focus on the integrating of the approach into the portable devices such as smartphone for on-site detection of mercury.

Dispersion and self-assembly of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) functionalized silver QDs in 6 CHBT liquid crystal

ABSTRACT Silver nanoparticles were synthesised using silver nitrate and tri-sodium citrate and were functionalized with 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) linking molecules. Functionalized silver nanoparticles dispersed within 4-(trans-4-n hexylcyclohexyl) isothiocyanatobenzoate (6CHBT) liquid crystal (LC) matrices have attracted significant attention because of their potential for tailoring tuneable surface plasmonic, optical, and electronic properties by controlling the self-assembly of silver dots. The unique combination of functionalized nanoparticles and 6CHBT LCs offers a versatile platform for manipulating interactions at the nanoscale. The dispersion of functionalized Ag nanoparticles within the LCs appears to substantially modify the plasmonic and opto-electronic properties of the Ag QDs. The formation and morphology of the self-assembled structures of silver nanoparticles were confirmed by Optical and Scanning Electron Microscopy. Optical microscopy (OM) and Scanning Electron Microscopy (SEM) images of Ag-doped 6CHBT confirmed the formation of nano-micro spheres, as well as ring and rod-like structures in LC media. We have used High-Resolution X-ray diffraction (HR-XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Surface-Enhanced Raman Spectroscopy (SERS), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Ultraviolet-visible-near-infrared Spectroscopy (UV-Vis-NIR), and Fluorescence (FL) Spectroscopy. We calculated the electronic properties such as the bandgap of the synthesised Ag QDs and functionalized Ag QDs using UV-Vis-NIR and Tauc’s plot curves. Surface-enhanced Raman spectroscopy, Optical microscopy, SEM, and UV-Vis-NIR spectral data were used to correlate the properties of the LC and QDs hybrid systems.

The Impact of Silver Nanoparticles Functionalized with Spirulina Protein Extract on Rats.

Background/Objectives: This study investigates the biocompatibility and physiological impacts of silver nanoparticles (AgNPs) functionalized with Spirulina protein extract (SPE) on laboratory rats. The objective was to assess and compare the systemic distribution, organ accumulation, and changes in hematological and biochemical parameters between biofunctionalized and non-functionalized silver nanoparticles. Methods: AgNPs were functionalized with SPE. Adult Wistar rats were administered these nanoparticles to assess their distribution across various organs using ICP-MS analysis. Hematological and biochemical markers were measured to evaluate systemic effects. Results: Functionalized silver nanoparticles demonstrated preferential accumulation in the brain, liver, and testicles, with significant clearance observed post-administration. The persistence of AgNPs SPE in reproductive organs was established. Hematological analysis revealed moderate changes, suggesting mild immune activation. Biochemical tests indicated transient increases in liver enzymes, signaling reversible hepatic stress. Conclusions: The biofunctionalization of AgNPs with Spirulina protein extract modifies the nanoparticles' systemic behavior and organ distribution, enhancing their biocompatibility while inducing minimal physiological stress. These findings support the potential of Spirulina-based coatings to mitigate the toxicity and enhance the therapeutic efficacy of nanomedical agents.

A Minor Groove Binder with Significant Cytotoxicity on Human Lung Cancer Cells: The Potential of Hesperetin Functionalised Silver Nanoparticles.

Natural drug functionalised silver (Ag) nanoparticles (NPs) have gained significant interest in pharmacology related applications due to their therapeutic efficiency. We have synthesised silver nanoparticle using hesperetin as a reducing and capping agent. This work aims to discuss the relevance of the hesperetin functionalised silver nanoparticles (H-AgNPs) in the field of nano-medicine. The article primarily investigates the anticancer activity of H-AgNPs and then their interactions with calf thymus DNA (ctDNA) through spectroscopic and thermodynamic techniques. The green synthesised H-AgNPs are stable, spherical in shape and size of 10 ± 3nm average diameter. The complex formation of H-AgNPs with ctDNA was established by UV-Visible absorption, fluorescent dye displacement assay, isothermal calorimetry and viscosity measurements. The binding constants obtained from these experiments were consistently in the order of 104 Mol-1. The melting temperature analysis and FTIR measurements confirmed that the structural alterations of ctDNA by the presence of H-AgNPs are minimal. All the thermodynamic variables and the endothermic binding nature were acquired from ITC experiments. All these experimental outcomes reveal the formation of H-AgNPs-ctDNA complex, and the results consistently verify the minor groove binding mode of H-AgNPs. The binding constant and limit of detection of 1.8μM found from the interaction studies imply the DNA detection efficiency of H-AgNPs. The cytotoxicity of H-AgNPs against A549 and L929 cell lines were determined by in vitro MTT cell viability assay and lactate dehydrogenase (LDH) assay. The cell viability and LDH enzyme release are confirmed that the H-AgNPs has high anticancer activity. Moreover, the calculated LD50 value for H-AgNPs against lung cancer cells is 118.49µl/ml, which is a low value comparing with the value for fibroblast cells (269.35µl/ml). In short, the results of in vitro cytotoxicity assays revealed that the synthesised nanoparticles can be considered in applications related to cancer treatments. Also, we have found that, H-AgNPs is a minor groove binder, and having high DNA detection efficiency.

A fluorimetric and colorimetric dual-mode sensor based on N, S co-doped carbon dots functionalized silver nanoparticles for glucose detection

A fluorescent-colorimetric dual-signal platform, N, S co-doped carbon dots functionalized silver nanoparticles (NS-CDs-AgNPs), was designed in situ by reducing AgNO3 in the presence of N, S co-doped carbon dots (NS-CDs) under the assistance of microwave irradiation for glucose determination. With the formation of silver nanoparticles (AgNPs), the intrinsic fluorescence of NS-CDs was quenched, showing the fluorescence state was off. Whereas the fluorescence of NS-CDs can be switched on when a trace amount of H2O2 was added. Based on this novel phenomenon, the peroxidase-like activity of NS-CDs-AgNPs by using 3,3′,5,5′-tetramethylbenzidine (TMB) chromogen and H2O2 as substrates was evaluated. The Km values of the prepared probe for H2O2 and TMB were 0.84 mM and 0.01 mM with the Vm of 6.65 × 10−8 M S−1 and 3.01 × 10−8 M S−1, respectively. The results showed that NS-CDs-AgNPs had good peroxidase-like activity and strong affinity to TMB and H2O2. It confirmed that there is a redox interaction between AgNPs and H2O2, and H2O2 can oxidize Ag to produce Ag+, which is the main reason that the fluorescence of NS-CDs-AgNPs can be activated by H2O2. The hydroxyl radical (·OH) was formed in the process of reaction, which can further oxidize TMB for color reaction. Meanwhile, glucose can be oxidized to produce H2O2 in the presence of glucose oxidase (GOx). Based on the phenomenon, a fluorimetric and colorimetric dual-mode sensor for glucose detection was established. Satisfactory results were obtained with the linear range of 0.1–80 μM for fluorimetric mode and 0.5–5 μM for colorimetric mode, respectively. Additionally, the LOD was below 0.32 μM and 0.21 μM, respectively. The method was successfully applied to determine the glucose in human serum with satisfactory recovery and RSD.

Mentha longifolia assisted nanostructures: An approach to obliterate microbial biofilms.

Microbes maneuver strategies to become incessant and biofilms perfectly play a role in scaling up virulence to cause long-lasting infections. The present study was designed to assess the use of an eco-friendly formulation of functionalized silver nanoparticles generated from Mentha longifolia leaf extract (MℓE) for the treatment of biofilm-producing microbes. Nanoparticles synthesized using MℓE as a reducing agent were optimized at different strengths of AgNO3 (1 mM, 2 mM, 3 mM, and 4 mM). Synthesis of M. longifolia silver nanoparticles (MℓAgNPs) was observed spectrophotometrically (450 nm) showing that MℓAgNPs (4 mM) had the highest absorbance. Various techniques e.g., Fourier transforms Infrared spectroscopy (FTIR), Dynamic light scattering (DLS), zeta potential (ZP), X-ray Diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) were used to characterize MℓAgNPs. In the present study, the Kirby-Bauer method revealed 4mM was the most detrimental conc. of MℓAgNPs with MIC and MBC values of 0.62 μg/mL and 1.25 μg/mL, 0.03 μg/mL and 0.078 μg/mL, and 0.07 μg/mL and 0.15 μg/mL against previously isolated and identified clinical strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, respectively. Moreover, the MℓAgNP antibiofilm activity was examined via tissue culture plate (TCP) assay that revealed biofilm inhibition of up to 87.09%, 85.6%, 83.11%, and 75.09% against E. coli, P. aeruginosa, K. pneumonia, and S. aureus, respectively. Herbal synthesized silver nanoparticles (MℓAgNPs) tend to have excellent antibacterial and antibiofilm properties and are promising for other biomedical applications involving the extrication of irksome biofilms. For our best knowledge, it is the first study on the use of the green-synthesized silver nanoparticle MℓAgNP as an antibiofilm agent, suggesting that this material has antibiotic, therapeutic, and industrial applications.

Non-toxic, Printable Starch Hydrogel Composite with Surface Functionalized Silver Nanoparticles Having Wide-Spectrum Antimicrobial Property

Non-toxic, Printable Starch Hydrogel Composite with Surface Functionalized Silver Nanoparticles Having Wide-Spectrum Antimicrobial Property

Selective colorimetric detection of trace chromium (III) based on silver nanoparticles aggregation via a domino-like reaction

A simple method for measuring and tracking Cr3+, particularly in water, are crucial for environmental protection and avoiding serious health implications. Herein, we report the synthesis of mannose functionalized silver nanoparticles (Ag@mannose NPs) for naked eye detection of Cr3+ ions. The Cr3+-induced selective stimuli on the surface of Ag@mannose NPs promote aggregation, resulting in a colour change from yellow to purple, which can be assessed by absorption spectroscopy. Zeta potential investigation revealed that the surface charge of Ag@mannose NPs was altered in the presence of Cr3+, resulting in aggregation, as validated by dynamic light scattering and transmission electron microscopy. Cyclic voltammetry study shows that the NPs surface stabilized with mannose was oxidized in the presence of Cr3+, causing a domino-like effect that resulted in NPs aggregation and colour change. The interference study demonstrated the selectivity and sensitivity of Ag@mannose NPs to Cr3+ over other metal ions. Ag@mannose NPs can detect Cr3+ in a wide pH range of 3–9. The lowest Cr3+ concentration detected by the naked eye is 0.6 μM (39 μg/L), under the World Health Organization permissible limit of chromium (50 μg/L) in drinking water. Finally, the Ag@mannose NPs sensing ability was demonstrated by detecting Cr3+ in tap and sewage water with a good recovery percentage.

Extracellular Matrix Mimicking Wound Microenvironment Responsive Amyloid-Heparin@TAAgNP Co-Assembled Hydrogel: An Effective Conductive Antibacterial Wound Healing Material.

Bioengineered composite hydrogel platforms made of a supramolecular coassembly have recently garnered significant attention as promising biomaterial-based healthcare therapeutics. The mechanical durability of amyloids, in conjunction with the structured charged framework rendered by biologically abundant key ECM component glycosaminoglycan, enables us to design minimalistic customized biomaterial suited for stimuli responsive therapy. In this study, by harnessing the heparin sulfate-binding aptitude of amyloid fibrils, we have constructed a pH-responsive extracellular matrix (ECM) mimicking hydrogel matrix. This effective biocompatible platform comprising heparin sulfate-amyloid coassembled hydrogel embedded with polyphenol functionalized silver nanoparticles not only provide a native skin ECM-like conductive environment but also provide wound-microenvironment responsive on-demand superior antibacterial efficacy for effective diabetic wound healing. Interestingly, both the cytocompatibility and antibacterial properties of this bioinspired matrix can be fine-tuned by controlling the mutual ratio of heparin sulfate-amyloid and incubated silver nanoparticle components, respectively. The designed biomaterial platform exhibits notable effectiveness in the treatment of chronic hyperglycemic wounds infected with multidrug-resistant bacteria, because of the integration of pH-responsive release characteristics of the incubated functionalized AgNP and the antibacterial amyloid fibrils. In addition to this, the aforementioned assemblage shows exceptional hemocompatibility with significant antibiofilm and antioxidant characteristics. Histological evidence of the incised skin tissue sections indicates that the fabricated composite hydrogel is also effective in controlling pro-inflammatory cytokines such as IL6 and TNFα expressions at the wound vicinity with significant upregulation of angiogenesis markers like CD31 and α-SMA.

Enhancement in the therapeutic efficacy of thymoquinone by its delivery through polypropylene glycol-functionalized silver nanoparticles

Metal nanoparticles with polymer capping have been used in a variety of analytical and biological applications. In this study, highly stable silver nanoparticles (AgNPs) functionalized with polypropylene glycol (PPG) were prepared using a chemical reduction approach. The drug delivery potential of the prepared PPG functionalized silver nanoparticles (PPG-AgNPs) was investigated using thymoquinone (TQ) as a model hydrophobic drug. The size, shape, drug encapsulation efficiency, and in-vitro release of PPG-AgNPs were investigated using different techniques such as Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), UV–Visible (UV-Vis) spectroscopy, Thermogravimetric analysis (TGA), X-ray powder diffraction (PXRD), and zeta sizer. An in-vitro experiment and atomic force microscopy were used to evaluate the antibacterial activity of thymoquinone loaded in PPG-AgNPs. The antibacterial activity of TQ was significantly boosted by its delivery through PPG-AgNPs compared to the direct application of TQ. Moreover, the biofilm inhibiting potential of the PPG-AgNPs/TQ is remarkably enhanced as compared to TQ alone which is further endorsed by the microscopic analysis. Current work sheds light on the various parameters that can be tweaked to generate a variety of AgNP characteristics for enhancement in the therapeutic efficiency of drugs like thymoquinone.

Appraising the antibacterial/antioxidant activities of vancomycin as a novel nano-platfom: Characterization, in-vitro assessment and in-vivo radio-tracking in animal models

The antibacterial nano-platforms have recently been developed as a result of an increasing prevalence of the bacterial resistance to various standard antibiotics. The aim of this study is to improve the vancomycin antibacterial efficacy against various resistant-bacteria using a unique nano-platform. Vancomycin functionalized silver nanoparticles (Ag-VanNPs) were properly synthesized showing a significant UV–Vis absorbance at 426 nm, average particle size of 20 ± 4.3 nm, mean hydrodynamic size of 185 ± 8.5 nm and zeta potential of +19 mV. Ag-VanNPs were investigated for its in-vitro antibacterial activity against various (G + ve and G-ve) bacterial strains declaring a synergistic antibacterial action that outperformed pure vancomycin. Compared to free vancomycin, Ag-VanNPs had showed significant reduction in MIC/MBC concentrations with FIC/FBC indices ≤0.5, suggesting a synergistic action with fewer adverse effects. The in-vitro viability and hemolysis studies revealed that Ag-VanNPs were non-toxic and biocompatible. The in-vivo studies of [131I] I–Ag-VanNPs in normal mice model showed their in-vivo stability and elimination mainly via hepatobiliary and renal pathways. Moreover, significant accumulations of [131I] I–Ag-VanNPs in the inflammatory muscle were seen in the in-vivo distribution of the inflamed mice model, which was represented by the potential T/NT ratios ≥1 at all research time points. Therefore, [131I] I–Ag-VanNPs may have better antibacterial activities against both kinds of Gram bacteria in addition to being a promising anti-inflammatory nano-radiopharmaceutical.

Membrane Penetrating-Cationic Peptide BP100 Functionalized Silver Nanoparticles as Efficient Antibacterial Agents

Membrane Penetrating-Cationic Peptide BP100 Functionalized Silver Nanoparticles as Efficient Antibacterial Agents

Synthesis and Characterization of Silver Nanoparticles Conjugated with Triazole‐N‐acetamide Thiazole Derivatives for Selective Detection of Cymoxanil in Complex Samples

AbstractCymoxanil (CYM) is one of the most important fungicides for various vegetables and fruits. However, its routine detection is still expensive due to high‐cost equipment. In this context, the silver nanoparticle‐based colorimetric probe was synthesized using triazole‐N‐acetamide thiazole (TAT) derivative as a stabilizer. The triazole‐N‐ acetamide thiazole (TAT) derivative functionalized silver nanoparticles (TAT‐AgNPs) were used as a probe for selective, efficient, rapid and quantitative determination of CYM in tap and river water. The characterization of TAT‐AgNPs was accomplished through UV‐visible, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Zetasizer analysis. Highly sensitive surface plasmonic resonance band at 400 nm indicated complete reduction of Ag+ by using 1 : 15 (v/v) (TAT: AgNO3). The limit of detection (LOD), which corresponds to signal‐to‐noise ratio 3, is 0.013 μmol L−1, showed a linear response as a function of CYM concentration from 1 to 100 μM. Furthermore, the probe shows good selectivity when exposed to a series of interfering pesticides. TAT‐AgNPs were also spiked with blood plasma and the effects of relevant interfering studies were evaluated. The nanosensor detects the CYM tap water and river water samples. It confirmed that nanosensor can detect CYM in biological and environmental samples.

Secnidazole functionalized silver nanoparticles as trace level colorimetric sensor for the detection of cadmium ions

Cadmium (Cd2+) has been declared as possible cancer causing heavy metal ion in humans and animals. Here in this research work we used an economical, facile, simpler, and one pot method for the formation of secnidazole derived silver nanoparticles (SEC-AgNPs). SEC-AgNPs were characterized through advanced techniques like, ultraviolet-visible (UV-Vis) spectroscopy, Fourier Transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) technique, zeta potential (ZP) analysis, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). These prepared SEC-AgNPs were investigated and verified as extremely sensitive, highly stable, rapidly responding and cost-effective colorimetric sensor for the low level detection of Cd2+. As-developed colorimetric Cd2+ sensor proved to be extremely selective in the presence of eighteen monovalent, divalent, trivalent and tetravalent metal ions and associated anions showing negligible interference with even ten-fold greater concentration of these ions as compared to Cd2+. The SEC-AgNPs based colorimetric Cd2+ sensor was linearly responsive to Cd2+ in the range of 5–27 µM with limit of detection (LOD) equal to 0.021 µM and LOQ value of 0.07 µM with R2 of 0.9965. The newly developed SEC-AgNPs based colorimetric sensor was successfully applied for cadmium detection in real tap water sample and human blood plasma samples within acceptable recovery levels.

Functionalized Silver Nano Particle Coated e-FBG Sensor For Specific and Rapid Detection of Chromium In Drinking Water

Functionalized Silver Nano Particle Coated e-FBG Sensor For Specific and Rapid Detection of Chromium In Drinking Water

Formation of lipid corona on Ag nanoparticles and its impact on Ag+ ion dissolution and aggregation of Ag nanoparticles against external stimuli

The application of lipid coated nanoparticles has been expanding in nanoscience over the past few years. Lipid corona formation is one of the novel ways for the lipid conjugation around the nanoparticles. Although several properties of nanoparticles and lipids are well reported in literature in last few years, the dependency of lipid corona formation on metallic core and surface ligands is poorly understood. The aggregation, surface oxidation and metal ions dissolution of nanoparticles limit their usefulness in various applications. Besides all the reported methods to overcome all of these limitations, lipid corona could be an alternative, feasible, and more efficient method. In the current manuscript, we investigate the interaction of aromatic amino acids (tyrosine and tryptophan) functionalized silver nanoparticles (Ag-Tyr and Ag-Trp NPs) with different surface charged and phase states lipid vesicles and compare them with the reported amino acid functionalized gold nanoparticles (Au-AA NPs). The effectiveness of different zwitterionic and positively charged lipid coated Ag-Tyr and Ag-Trp NPs to prevent the aggregation and Ag+ ion dissolution of Ag NPs against different external stimuli (acidic pH, high NaCl concentration, and freeze-thaw cycles) are investigated. Our results reveal that surface ligands around the NPs play crucial role for lipid corona formation irrespective of the metallic core of NPs. Although all the lipid coated Ag NPs exhibit greater stability against external stimuli than native Ag NPs, zwitterionic lipid coated Ag NPs is better choice than positively charged lipid coated Ag NPs. This study on lipid corona and its stability will help the nanoresearcher to choose the suitable lipid for lipid corona formation.

A green-micro-synthesis of curcumin functionalized silver nanoparticles for bacteria inhibition and glucose sensor electrode modifier

A novel strategy for silver nanoparticles synthesis has been developed in a simple way. The method promotes green synthesis by using demineralized water as the primary solvent, sunlight as the energy source, and the small volume of the reaction. The silver nanoparticles were obtained by utilizing the autooxidation pathways of curcumin that was dissolved in ethanol. Interestingly, the volume of curcumin at the microliter level could produce AgNPs with good properties. The materials were characterized using UV–Visible spectrophotometer, Fourier Transform Infra-Red Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX), and Nano Particle Analyzer. The bacterial inhibition activity of silver nanoparticles (cAgNPs) was tested against Eschericia coli ATRCC6633 and Staphylococcus aureus ATRCC6633. This material showed good activity in inhibiting Gram-negative and Gram-positive bacteria compared to the control Ag + ion and curcumin. MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) test results exhibited a good performance of cAgNPs against E. coli ATRCC6633 and S. aureus ATRCC6633. Carbon paste electrode (CPE) modified with cAgNPs was used to detect glucose using Differential Pulse Voltammetry (DPV) technique. The cAgNPs were electrodeposited on CPE using cyclic voltammetry (CV) technique. The modified electrode showed promising results to be applied for glucose detection due to its good linearity and sensitivity. In addition, this work will give new insight into a sustainable method for producing silver nanomaterials that provide good bacteria inhibition and enhance the CPE performance to detect glucose.

Detection of Fe(III) ion based on bifunctionalized silver nanoparticles: Sensitivity, selectivity and environmental safety

Functionalized silver nanoparticles (AgNPs) are widely used as optical sensors for heavy metal ions in water, due to their versatile, easy and cheap preparations and due to their peculiar physico-chemical properties. Surface functionalization plays a key role in AgNPs chemical-physical behavior as capping agents can affect sensitivity, selectivity but alsoenvironmental safety. In this framework, AgNPs are synthetised and properly functionalized using two capping agents to induce hydrophilic behavior and selectivity, respectively citrate (cit) and glutathione (GSH). The opportune choice of these capping agents induces size control and stability for AgNPs-cit-GSH in water (Ø = 4 ± 0.2 nm; ζ-potential = - 60 ± 1 mV) and make available selectively detection of Fe (III) in the range 0.5–10.0 ppm. Environmental safety was also evaluated using standardized ecotoxicity assays (ecosafety) with freshwater and marine microalgae which show a low-to-negligible effects, with exception only at the highest tested concentration (10 mg/L) but only for the freshwater one.