Conjugated Silver Nanoparticles Research Articles

Acute Toxicity, Anti-diabetic, and Anti-cancerous Potential of Trillium Govanianum-conjugated Silver Nanoparticles in Balb/c Mice.

The current study aimed to develop an economic plant-based therapeutic agent to improve the treatment strategies for diseases at the nano-scale because Cancer and Diabetes mellitus are major concerns in developing countries. Therefore, in vitro and in vivo antidiabetic and anti-cancerous activities of Trillium govanianum conjugated silver nanoparticles were assessed. In the current study synthesis of silver nanoparticles using Trillium govanianum and characterization were done using a scanning electron microscope, UV-visible spectrophotometer, and FTIR analysis. The in vitro and in vivo anti-diabetic and anti-cancerous potential (200 mg/kg and 400 mg/kg) were carried out. It was discovered that Balb/c mice did not show any major alterations during observation of acute oral toxicity when administered orally both TGaqu (1000 mg/kg) and TGAgNPs (1000 mg/kg), and results revealed that 1000 mg/kg is not lethal dose as did not find any abnormalities in epidermal and dermal layers when exposed to TGAgNPs. In vitro studies showed that TGAgNPs could not only inhibit alpha-glucosidase and protein kinases but were also potent against the brine shrimp. Though, a significant reduction in blood glucose levels and significant anti-cancerous effects was recorded when alloxan-treated and CCl4-induced mice were treated with TGAgNPs and TGaqu. Both in vivo and in vitro studies revealed that TGaqu and TGAgNPs are not toxic at 200 mg/kg, 400 mg/kg, and 1000 mg/kg doses and possess strong anti-diabetic and anti-cancerous effects due to the presence of phyto-constituents. Further, suggesting that green synthesized silver nanoparticles could be used in pharmaceutical industries to develop potent therapeutic agents.

Photodynamic antibacterial chemotherapy activities of P(V) and Ga(III) triarylcorroles and their silver nanoparticle conjugates

Photodynamic antibacterial chemotherapy activities of P(V) and Ga(III) triarylcorroles and their silver nanoparticle conjugates

Synthesis, Characterization, Phytochemistry, and Therapeutic Potential of Azadirachta indica Conjugated Silver Nanoparticles: A Comprehensive Study on Antidiabetic and Antioxidant Properties.

Nanotechnology has become a major topic of study, particularly in the medical and health domains. Because nanomedicine has a higher recovery rate than other conventional drugs, it has attracted more attention. Green synthesis is the most efficient and sustainable method of creating nanoparticles. The current work used ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction to thoroughly characterize the synthesized silver nanoparticles (AgNPs) from Azadirachta indica leaf extract. Characterization confirmed the synthesis of the AgNPs along with the possible linkage of the phytochemicals with the silver as well as the quantitative analysis and nature of NPs. The antioxidant activity of AgNPs and neem extract was measured by the 2,2-diphenyl-1-picrylhydrazyl assay using various concentrations (20, 40, 60, 80, and 100µg/ml). Additionally, using diabetic mice that had been given alloxan, the in vivo antidiabetic potential of biosynthesized AgNPs was assessed. Eight groups of mice were used to assess the antidiabetic activity: one control group and seven experimental groups (untreated, extract-treated, AgNPs at low and high doses, standard drug, low dose of AgNPs + drug, and high dose of AgNPs + drug). At days 0, 7, 14, 21, and 28, blood glucose levels and body weight were measured. After 28days, the mice were dissected, and the liver, kidney, and pancreas were examined histologically. The results depicted that the AgNPs showed higher (significant) radical scavenging activity (IC50 = 35.2µg/ml) than extract (IC50 = 93.0µg/ml) and ascorbic acid (IC50 = 64.6µg/ml). The outcomes demonstrated that biosynthesized AgNPs had a great deal of promise as an antidiabetic agent and exhibited remarkable effects in diabetic mice given AgNPs, extract, and drug. Remarkable improvement in the body weight and blood glucose level of mice treated with high doses of AgNPs and drug was observed. The body weight and blood glucose level of diabetic mice treated with a high dose of AgNPs + standard drug showed significant improvement, going from 28.7 ± 0.2 to 35.6 ± 0.3g and 248 ± 0.3 to 109 ± 0.1mg/dl, respectively. Significant regeneration was also observed in the histomorphology of the kidney, liver's central vein, and islets of Langerhans after treatment with biosynthesized AgNPs. Diabetic mice given a high dose of AgNPs and drug displayed architecture of the kidney, liver, and pancreas that was nearly identical to that of the control group. According to the current research, biosynthesized AgNPs have strong antioxidant and antidiabetic potential and may eventually provide a less expensive option for the treatment of diabetes.

The Photodynamic Antibacterial Activity Properties of a Series of Indium(III) Porphyrins and their Gold and Silver Nanoparticle Conjugates

AbstractIn(III) tetraarylporphyrin complexes with 4‐thiomethylphenyl (1‐InPor), thien‐3‐yl (2‐InPor), thien‐2‐yl (3‐InPor) and 5‐bromothien‐2‐yl (4‐InPor) meso‐aryl rings have been synthesized and characterized. The complexes have been conjugated to gold and silver nanoparticles (AuNPs and AgNPs). The photodynamic antimicrobial chemotherapy (PACT) activities of 1–4‐InPor and their AuNP and AgNP conjugates have been investigated against both planktonic bacteria and biofilms of Gram‐(+) S. aureus and Gram‐(−) E. coli. 2.5 μg.mL−1 solutions of 1–4‐InPor exhibited favorable PACT activities against planktonic S. aureus with high Log10 reduction values in the 4.28–7.69 range upon 75 min photoirradiation with a Thorlabs M625L3 LED (240 mW.cm−2) mounted onto the illumination chamber of a Modulight 7710 medical laser system to provide a dose at the well‐plate of 86 mJ.cm−2.min−1. In contrast, low values in the 1.4–1.9 range were obtained against E. coli with 10 μg.mL−1 solutions. 1–4‐InPor exhibited relatively low PACT activity against the biofilm cells of S. aureus and E. coli. Conjugation of 1–4‐InPor to AgNPs and AuNPs significantly enhanced the PACT activities. This is demonstrated by the complete eradication of planktonic S. aureus at shorter irradiation times with high Log10 values>7.69 and moderate Log10 values>2 against planktonic E. coli for the meso‐thienylporphyrin conjugates.

Synthesis, characterisation and in vitro anticancer activity of conjugated protease inhibitor-silver nanoparticles (AgNPs-PI) against human breast MCF-7 and prostate PC-3 cancer cell lines.

The conjugated silver nanoparticles using biomolecules have attracted great attention of researchers because physical dimensions and surface chemistry play important roles in toxicity and biocompatibility of AgNPs. Hence, in the current study, synthesis of bio-conjugated AgNPs with protein protease inhibitor (PI) isolated from Streptomyces spp. is reported. UV-visible spectra of PI and AgNPs showed stronger peaks at 280 and 405nm, confirming the synthesis of conjugated AgNPs-PI. TEM and SEM images of AgNPs-PI showed spherical-shaped nanoparticles with a slight increase in particle size and thin amorphous layer around the surface of silver nanomaterial. Circular dichroism, FT-IR and fluorescence spectral studies confirmed AgNPs-PI conjugation. Conjugated AgNPs-PI showed excellent anticancer potential than AgNPs and protease inhibitor separately on human breast MCF-7 and prostate PC-3 cell lines. The findings revealed that surface modification of AgNPs with protein protease inhibitor stabilised the nanomaterial and increased its anticancer activity.

Green Synthesis and Characterization of Biologically Synthesized and Antibiotic-Conjugated Silver Nanoparticles followed by Post-Synthesis Assessment for Antibacterial and Antioxidant Applications.

The paper presents the antibacterial and antioxidant activities of silver nanoparticles (AgNPs) when conjugated with two antibiotics levofloxacin and ciprofloxacin as well as biologically synthesized nanoparticles from Moringa oleifera and Curcuma longa. Leaves of Moringa and powder of Curcuma were used in the green synthesis of silver nanoparticles. Ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used for the characterization of the synthesized silver nanoparticles. Comparison of levofloxacin and ciprofloxacin and their conjugated AgNPs was also studied for antibacterial and antioxidant activity. The synthesis of Moringa-AgNPs, turmeric-AgNPs, levofloxacin-AgNPs, and ciprofloxacin-AgNPs was confirmed by UV spectroscopy. An absorption peak value of 400-450 nm was observed, and light to dark brown color indicated the synthesis of AgNPs. Moringa-AgNPs revealed high antioxidant activity (80.3 ± 3.14) among all of the synthesized AgNPs. Lev-AgNPs displayed the highest zone of inhibition for Staphylococcus aureus, while in Escherichia coli, Cip-AgNPs showed high antibacterial activity. Furthermore, AgNPs synthesized using green methods exhibit high and efficient antimicrobial activities against two food-borne pathogens. Biologically synthesized nanoparticles exhibited antibacterial activity against E. coli (13.73 ± 0.46 with Tur-AgNPs and 13.53 ± 0.32 with Mor-AgNPs) and S. aureus (14.16 ± 0.24 with Tur-AgNPs and 13.36 ± 0.77 with Mor-AgNPs) by using a well diffusion method with significant shrinkage and damage of the bacterial cell wall, whereas antibiotic-conjugated nanoparticles showed high antibacterial activity compared to biologically synthesized nanoparticles with 14.4 ± 0.37 for Cip-AgNPs and 13.93 ± 0.2 for Lev-AgNPs for E. coli and 13.3 ± 0.43 for Cip-AgNPs and 14.33 ± 0.12 for Lev-AgNPs for S. aureus. The enhanced efficiency of conjugated silver nanoparticles is attributed to their increased surface area compared to larger particles. Conjugation of different functional groups contributes to improved reactivity, creating active sites for catalytic reactions. Additionally, the precise control over the size and shape of green-synthesized nanoparticles further augments their catalytic and antibiotic activities.

Therapeutic Potential of Aloe vera and Aloe vera-Conjugated Silver Nanoparticles on Mice Exposed to Hexavalent Chromium.

Hexavalent chromium (Cr (VI)) is a hazardous heavy metal that induces hepatotoxicity and nephrotoxicity. Thus, this study was planned to explore the ameliorating capacity of Aloe vera leaf gel extract (AV) and their conjugated silver nanoparticles (AVNP) against Cr (VI) induced hepatotoxicity and renal toxicity. The organ indices, level of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, malondialdehyde, total protein, and creatinine in blood serum were measured. The histopathological and micrometric analysis of the hepatic and renal tissue sections were studied. The hepatosomatic index was raised significantly (0.098 ± 0.13g) in Cr treated group. The blood serum level of AST (484 ± 10.7 U/L), ALT (163 ± 5.5 U/L), ALP (336.7 ± 9.5 U/L), MDA (642.3 ± 28.3 U/L), and creatinine (4.0 ± 0.1mg/dL) were increased significantly, whereas total protein level was declined (2.8 ± 0.3g/dL) significantly in Cr exposed group. In the histopathological study, necrosis, disturbed hepatic cords, impaired glomeruli, and Bowman's capsule were noted. Micrometric data from the liver and kidney revealed a significant surge in the size of hepatocytes and their nuclei (1188.2 ± 467.7µ2 and 456.5 ± 205.6µ2) and CSA of glomeruli and Bowman's capsule (9051.8 ± 249.8µ2 and 11,835.5 ± 336.7µ2) in Cr (VI) exposed group, whereas the brush border (10.2 ± 4.0µ) size declined significantly. The administration of AV and AVNP reduced the oxidative stress induced by Cr (VI).

Simple method for optical characterization of surface agents on conjugated silver nanoparticles

In this study, a simple formula has been proposed to calculate the refractive index of surface agents of silver nanoparticles (Ag NPs) by using the plasmonic peak of the absorption spectra of dispersed Ag nano-colloids. The basis of the study is the shift in the localized surface plasmon resonance (LSPR) of Ag NPs upon alteration of surface agents. The color changes in a typical metal nano-colloid are mainly due to the shift in the LSPR, which is caused because of electrical interactions of surface agents on the particles. There are some theoretical models to simulate the absorption spectrum, but using these methods to evaluate the plasmonic peak is not facile for a wide range of users. Here, the required simulations were performed for different values of the refractive index of surface agents and particle sizes, and the absorption spectrum and dispersive curves were accordingly plotted. A simple formula was obtained between the wavelength of the plasmonic peak, the refractive index of the shell of surface agents, and the ratio of the hydrodynamic diameter to Feret size of the particles (R0). The refractive index of the surface agents can be calculated by n2=λmax−(202.3R02−748.6R0+947.4)−152.2R02+561.3R0−405.1, where λmax (in nanometer) is the wavelength of the absorption peak due to LSPR. This method can pave the way for experimenters to obtain the refractive index and consequently the type of surface agents around Ag NPs without the need for numerical or mathematical operations. It can also be useful in analyzing the spectral diagnosis of biological agents such as viral antibodies and antigens.

Optimizing the Synthesis of Folic Acid Conjugated Silver Nanoparticles by Box-Behnken Design to Target Breast Cancer Cells

In this study, the synthesis of folic acid conjugated silver nanoparticles (FA&AgNPs) was optimized. FA&AgNPs were synthesized by reduction of silver nitrate with folic acid, which is widely used to target folate receptors in cancer cells. Five independent variables (stirring speed, AgNO3 concentration, folic acid concentration, AgNO3 volume/folic acid volume, and temperature) that were effective on silver nanoparticle synthesis were determined. Based on the independent variables, an experimental plan consisting of 46 experiments was created using the Box-Behnken design (BBD). Nanoparticle formation, physical color change, UV-Vis absorption spectroscopy, Dynamic Light Scattering (DLS) analysis, and Fourier Transform Infrared (FTIR) analysis were evaluated. The mean particle size and zeta potential of FA&AgNPs produced under optimized conditions were measured as 207±4.3 nm and -51.6 mV±2.5, respectively. Cytotoxicity tests were performed to evaluate the anticancer activity of FA&AgNPs in breast cancer cell lines. The IC50 values for MDA-MB-231 breast cancer cells at 24 hours and 48 hours were 20.0 µg/mL and 16.9 µg/mL, respectively, and 26.3 µg/mL and 31.5 µg/mL for MCF-7 cells. The findings indicated that FA&AgNPs have the potential to be an effective anticancer agent in breast cancer cells.

Effect of Peptides on the Synthesis, Properties and Wound Healing Capacity of Silver Nanoparticles.

The aim of this study is the synthesis of novel peptide-silver nanoparticle conjugates with enhanced wound healing capacity. Peptide-silver nanoparticle conjugates were synthesized using myristoyl tetrapeptide 6 (MT6) or copper tripeptide 1 (CuTP1). Peptide-free silver nanoparticles (AgNP) were synthesized using NaBH4 and sodium citrate and were used as control. The addition of the peptides during or after the synthesis of nanoparticles and its impact on the properties of the synthesized peptide-silver nanoparticle conjugates were assessed. The monitoring of the synthesis of nanoparticles was achieved using ultraviolet-visible spectrophotometry (UV-/Vis). The characteristics and colloidal stability of the nanoparticles (size and ζ-potential distribution, morphology, composition and structure) were monitored using dynamic laser scattering (DLS), transmission electron microscopy (TEM), atomic absorption spectroscopy (AAS) and X-ray diffraction (XRD). The wound healing capacity of the peptide-silver nanoparticle conjugates was assessed using scratch test assay on fibroblasts (NIH/3T3). The results indicated that the addition of the peptides during the synthesis of nanoparticles lead to better yield of the reaction and more effective capping while the size distribution and ζ-potential of the conjugates indicated long-term colloidal stability. The MT6-AgNP conjugate exhibited 71.97 ± 4.35% wound closure, which was about 5.48-fold higher (p < 0.05) than the corresponding free MT6. The CuTP1-AgNP conjugate exhibited 62.37 ± 18.33% wound closure that was better by 2.82 fold (p < 0.05) compared to the corresponding free CuTP1. Both peptides led to the synthesis of silver nanoparticle conjugates with enhanced wound healing capacity compared to the respective free peptide or to the peptide-free AgNP (29.53 ± 4.71% wound closure, p < 0.05). Our findings demonstrated that the synthetized peptide-silver nanoparticle conjugates are promising ingredients for wound care formulation.

Antibacterial and antibiofilm efficacy of colistin & meropenem conjugated silver nanoparticles against Escherichia coli and Klebsiella pneumoniae.

The progressive increase in infections caused by multidrug-resistant (MDR) Gram-negative bacteria and the emergence of resistance to last-resort antimicrobial drugs in recent years necessitate the development of new therapeutic strategies. This study was conducted to obtain nanostructured antimicrobials by conjugating colistin (COL) and meropenem (MEM) antibiotics with biosynthesized silver nanoparticles (bio-AgNPs) via the green synthesis method using Rosa damascena extract, and to investigate the antibacterial and antibiofilm activity of these nanostructures against Escherichia coli and Klebsiella pneumoniae strains. Ultraviolet-visible spectrophotometry, high-resolution-transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Fourier transform-infrared spectroscopy analyses were performed to determine the physical and chemical properties of synthesized bio-AgNPs, COL@bio-AgNPs, MEM@bio-AgNPs, and COL&MEM@bio-AgNPs. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration of nanoparticles were determined on standard and MDR clinical strains. The antibiofilm efficacy and cytotoxic effect of nanoparticles were evaluated by the crystal violet dye method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide dye method, respectively. The characterization analyses demonstrated that the synthesized nanoparticles had crystal structure and spherical morphology (5.6-30.2 nm in size). Antibiotic conjugated nanoparticles exhibited better antimicrobial activity and lower MIC values (0.125-4 µg/mL) on the tested strains compared to free antibiotics, and MIC values were decreased up to 1024-fold (p < 0.05). Antibiotic conjugated nanoparticles were found to be more effective in biofilm eradication than free antibiotics and bio-AgNPs and had a less inhibitory effect on peripheral blood mononuclear cell viability. The findings revealed that antibiotic-conjugated nanoparticles have the potential to be used as an effective antimicrobial drug against MDR E. coli and K. pneumoniae strains.

Evaluating the Effect of pH, Temperature and Concentration on Antioxidant and Antibacterial Potential of Spectroscopically, Spectrophotometrically and Microscopically Characterized Mentha Spicata Capped Silver Nanoparticles.

The use of traditional plants has been tremendously increased due to their higher biological impact, minimal side effects, and comparatively low cost. Moreover, the emergence of antibacterial resistance is also shifting the scientific community to reconsider herbal remedies which provide relatively safer, cheap and biologically tolerable solutions. The present research was designed to fabricate the Mentha spicata conjugated silver nanoparticles (Me-AgNPs). Furthermore, the assessment of the bactericidal potential of Me-AgNPs against various bacterial strains was another motive behind this study. Fabricated NPs were characterized with the help of the UV-Visible spectrophotometric analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). Me-AgNPs showed a significant zone of inhibition (23 ± 0.2 mm) at 8 mg/mL against Staphylococcus aureus and a 4.0 ± 0.2 mm zone of growth inhibition at 2 mg/mL against Aeromonas veronii. The stability of Me-AgNPs was assessed at various pH (4, 7 and 11) and temperatures (25 °C, 4 °C, 37 °C, 75 °C). The significant zones of inhibition (11.3 ± 0.3 mm, 8.3 ± 0.3mm, 14.3 ± 0.3 mm, and 7.6 ± 0.2 mm) were observed at pH 11 against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae, respectively. Growth inhibition zones (14.0 ± 0.5 mm and 13.0 ± 0.5 mm) were also determined against B. subtilis and S. aureus at 25 °C. DPPH bioassay was conducted to find the antioxidant properties of Me-AgNPs. The highest (38.66 ± 0.2%) free radical scavenging activity was shown by Me-AgNPs at 4 mg/mL. Present study results concluded that biogenic Me-AgNPs have bactericidal as well as anti-oxidative potential. Moreover, these green synthesized Me-AgNPs could maintain their potency and stability at a wide range of pH and temperature.

Preparation and Characterization of Silver Nanoparticle Cross-linked Polymeric Cages by Freshwater Cyanobacteria and their Bactericidal Evaluation against Multi-Drug Resistant Bacteria

Abstract: Introduction: Over the past 60 years, numerous modern types of antibiotics have been developed. Antibiotic overuse has been largely responsible for spreading resistant strains that endangering the public's health at an alarming rate. It prompted the pacing advert of new resistance mechanisms and a lessening in the productivity of treating common infectious. Objectives: The present study emphasizes using cyanobacteria silver nanoparticle conjugates (Ag-NPCs) as a drug delivery system to predominantly control Multi-Drug Resistant bacteria. Materials and Methods: The Ag-NPCs were prepared using a sodium alginate calcium chloride cross-linking process. The Ag-NPCs properties have been characterized by UV-vis-Spectroscopy, FTIR (Fourier Transform Infrared Spectroscopy), Transmission Electron Microscopy (TEM), EDAX (Energy Dispersive Analysis X-Ray), and Scanning Electron Microscopic analysis (SEM) analysis. Results: The SEM and TEM analysis showed that Ag-NPCs have been bio-reduced to the size of 20-22nm that are trapped on the surface. FTIR analysis and EDAX analysis are used to confirm the bio-reduction of Ag-NPCs. The antibacterial activity of Ag-NPCs showed prominent results against four MDR bacteria by exhibiting a zone of inhibition with a range of 2-10 mm. Keywords: Cyanobacteria, Multi-Drug Resistant bacteria, Cyanobacteria Silver nanoparticle conjugates, Drug delivery system, Antibacterial activity.

Photochemical preparation, characterization and formation kinetics of riboflavin conjugated silver nanoparticles

Riboflavin conjugated silver nanoparticles (RF–AgNPs) have been synthesized by photoreduction of Ag+ ions and characterized by UV–visible, X-ray diffraction (XRD), FTIR spectroscopy, spectrofluorimetry, dynamic light scattering (DLS) and atomic force microscopy (AFM). The RF–AgNPs exhibit a typical surface plasmon resonance (SPR) peak at 422 nm due to the interaction of RF and AgNPs. FTIR studies indicate the appearance of an intense absorption peak at 2920 cm–1 due to the interaction of RF and Ag. AFM studies indicate that the RF–AgNPs are spherical and polydisperse in nature (57–73 nm), which nicely complement the hydrodynamic radii (57.9–72.2 nm) measured by DLS. None of the tested concentrations (1-250 µg mL−1) of RF–conjugated AgNPs show any adverse effect on normal mouse fibroblast and cancerous non-small lung carcinoma cell lines. At acidic pH (2.0–6.2) aggregation of RF–AgNPs occurs due to an increase in the ionic strength of the medium. The rates of formation of RF–AgNPs on UV and visible light irradiation have been determined in the pH range of 8.0–10.5 and at different concentrations of Ag+ ions. The photochemical formation of RF–AgNPs follows a biphasic first–order reaction probably due to the formation of AgNPs in the first phase (fast) and the adsorption of RF on AgNPs to yield RF–AgNPs in the second phase (slow).

A Silver Nanoparticles-Based Selective and Sensitive Colorimetric Assay for Ciprofloxacin in Biological, Environmental, and Commercial Samples

The wide-spread usage of ciprofloxacin (CIP) resulted in its presence in different parts of the ecosystem. Thus, a simple, reliable, on-spot detection method for CIP is required in environmental context. Herein, a colorimetric assay is developed for the detection of CIP based on the branched polyethyleneimine (PEI) conjugated silver nanoparticles (PEI-AgNPs). AgNPs are prepared using PEI as stabilizing agent following a simple one-pot two-phase procedure. The prepared PEI-AgNPs are subsequently used for an efficient and selective detection of CIP. The characteristic yellow colour of PEI-AgNPs changed to colourless when CIP was added which was further confirmed by quenching in the intensity of the SPR (surface plasmon resonance) band (hypochromic shift). The proposed method is efficient for the quantitation of CIP in a linear dynamic range (LDR) of 0.1–200 µM with a limit of detection (LOD) of 0.038 µM, and limit of quantification (LOQ) of 0.12 µM. The developed method is selective, efficient, and sensitive to CIP in the presence of numerous interfering species and in real biological, environmental, and commercial pharmaceutical samples. Excellent performance of the proposed method compared to UV-Vis spectroscopy and UPLC in environmental, biological, and commercial pharmaceutical samples is demonstrated.

Ameliorative effect of Nigella sativa conjugated silver nanoparticles against chromium-induced hepatotoxicity and renal toxicity in mice

Hexavalent chromium induces oxidative stress in the liver and kidney. Therefore an in vivo study was designed to investigate the modulatory effect of biosynthesized AgNP against Cr (VI) induced hepatotoxicity and nephrotoxicity. The organs index, serum level of ALT, AST, ALP, MDA, total protein and creatinine were measured. The histopathology and micrometry of the liver and kidney were examined. The liver index was significantly increased (0.098 ± 0.13 g) with slight increase in kidney index in Cr exposed group. The serum level of ALT (163.0 ± 5.5 U/L), AST (484.0 ± 10.7 U/L), ALP (337.6 ± 9.6 U/L), MDA (641.2 ± 29.2 U/L), and creatinine (2.9 ± 0.2 mg/dL) were significantly increased (P ≤ 0.05) with significant decrease in total protein level (2.9 ± 0.2 g/dL) (P ≤ 0.05) in chromium treated group. In histopathology, distorted hepatic cords, necrosis, damaged glomerulus and Bowman’s capsule were observed. Micrometric studies of the liver and kidney showed significant increase in size of hepatocytes (1188.2 ± 467.7 µ2) and their nuclei (456.4 ± 206.7 µ2), ACSA of Bowman’s capsule (11835.5 ± 336.7 µ2) and glomerulus (9051.8 ± 249.8 µ2) in Cr (VI) treated group. The size of brush border (10.1 ± 3.0 µ) was significantly reduced in Cr (VI) treated group however the ACSA of lumen was not significantly changed. With the administration of NSSE and Nigella sativa AgNPs, decreased the oxidative damage caused by Cr (V).

Phytochemical screening, toxicological studies of aqueous whole plant extract and characterized conjugated silver nanoparticles on liver function biomarkers

Assessment of the safety and possible effects aqueous whole plant extract and characterized conjugated silver nanoparticles derived from Euphorbia heterophylla as related to liver function can produce on the end users make toxicological studies a must. The phytochemical screening and toxicological studies of aqueous extract and characterized conjugated silver nanoparticles (CCAgNPs) were carried out using standard techniques. Phytochemicals such as: saponins, flavonoids, terpenoids, cardiac glycosides, tannins, phenols, alkaloids, steroids and reducing sugars were present in aqueous extract of whole plant Euphorbia heterophylla (AQEWEH). There was a reduction in the body weights of Wistar albino rats except an increment at a dose of 600 mg/kgbw. However, the highest average body weight of 176.50 g was obtained when 10 mg/kgbw of AQEWEH was administered to Wistar albino rats while 600 mg/kgbw of CCAgNPs gave the highest body weight of 152.50 g. Increment in serum asparte aminotransferase, alanine aminotransferase, total bilirubin, reduction in total protein and urea concentration are indicative of hepatocellular dysfunction and cholestatic pattern. The implication of this study is that for both AQEWEH and CCAgNPs to be used as therapeutic agents and administered to man and animals, their safety doses must be determined.

Synthesis of conjugated silver nanoparticles of 18β-glycyrrhetinic acid peptide conjugate (GAP) as a colorimetric probe for barium ions

In this study, we present a direct colorimetric technique for the sensitive and specific detection of Ba2+ ions in laboratory tap and river water utilizing functionalized 18β-glycyrrhetinic acid peptide silver nanoparticles (GAP-AgNPs).

Preparation of a glassy carbon electrode modified with saffron conjugated silver nanoparticles for the sensitive and selective electroanalytical determination of amoxicillin in urine samples.

Determination of antibiotics is crucial in order to assess their potential impacts on human health and the environment. This study aimed to develop a modified glassy carbon electrode with saffron conjugated silver nanoparticles for the determination of amoxicillin antibiotic in urine samples. The modified electrode was prepared by electrodeposition of silver nanoparticles on the electrode surface, followed by deposition of amoxicillin on the surface. The electrochemical behavior of the modified electrode was studied by cyclic voltammetry and square wave voltammetry. The results showed that the modified electrode exhibited enhanced electrocatalytic activity toward the oxidation of amoxicillin. The calibration curve was linear in the concentration range from 1.273 × 10-4 g L-1 to 2.217 × 10-3 g L-1, with a high linear correlation coefficient of 0.9998. The detection limit was determined to be 4.199 × 10-5 g L-1. The precision of the sensor was adequate, with relative standard deviations of 4.3% and 4.0% for AMX concentrations of 9.199 × 10-5 g L-1 and 1.194 × 10-4 g L-1, respectively. The modified electrode was then applied to the determination of amoxicillin in urine samples. The method showed linearity over the amoxicillin concentration range from 0.00 to 2.00 × 10-4 g L-1, with a detection limit of 9.739 × 10-6 g L-1, indicating the potential of the modified electrode for the determination of amoxicillin in biological samples. Overall, the modified glassy carbon electrode with silver nanoparticles showed very promising results for the sensitive and selective determination of amoxicillin in urine samples.

Electrochemical immunoassay of antibodies using freshly prepared and aged conjugates of silver nanoparticles

In this work, silver nanoparticles (AgNPs) were conjugated with immunoglobulins G using a simple passive adsorption method and the composition and properties of freshly prepared (Ab@AgNPs) and aged (Ab@AgNP/Ag2SNPs) conjugates were investigated for the first time by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and voltammetry. It was found that the state of the AgNPs in the conjugates changed during storage. In the freshly prepared Ab@AgNPs conjugates, silver is present in the metallic state only, while the aged Ab@AgNP/Ag2SNPs conjugates are characterized by the presence of a metallic core of AgNPs coated with a “corona” of Ag2S. This affects the selection of voltammetric conditions for recording an analytical signal from the silver label in the conjugates. The Ab@AgNPs and Ab@AgNP/Ag2SNPs conjugates were successfully tested in the electrochemical immunoassay of dog immunoglobulins as a model. A solid-phase indirect non-competitive assay was performed using a 96-well ELISA plate. To record intense analytical signals from the silver conjugates by linear scan anodic stripping voltammetry (LSASV) on a carbon composite electrode (CCE), they were preliminarily dissolved in acidic solutions. In the case of the Ab@AgNPs conjugate, a nitric acid solution (1 mol L−1) was used to dissolve silver conjugates, while in the case of Ab@AgNP/Ag2SNPs, a 1:1 mixture of 1 mol L−1 CH3COOH and 1 mol L−1 HNO3 was used. The CH3COOH dissolved the Ag2S “corona”, and HNO3 dissolved the silver core of the Ab@AgNP/Ag2SNPs conjugate.This work opens up the possibility of the prolonged use of silver conjugates in electrochemical immunoassay, which can be used in commercial test systems for immunological studies as an alternative to conjugates labelled with enzyme labels.