Photo-catalytic and biological applications of phyto-functionalized zinc oxide nanoparticles synthesized using a polar extract of Equisetum diffusum D.

In this study, zinc oxide nanoparticles (ZnO NPs) were fabricated using Equisetum diffusum D extract and their diverse properties and applications were studied. Phytochemical analysis confirmed the presence of phenols and flavonoids in the plant extract, playing a crucial role in the stabilization and reduction of the synthesized nanoparticles. The greenly synthesized ZnO NPs were characterized through a range of analytical techniques. UV-visible spectrophotometry has been employed to investigate their optical characteristics. FTIR spectroscopy was employed to identify the functional groups responsible for the synthesis of the ZnO NPs. The structural properties were evaluated using XRD. The morphology and size distribution of the synthesized NPs were examined using SEM, DLS, and elemental spectra evaluated using EDX. The charge that develops at the interface was analyzed using zeta potential which accounts for stability of the NPs. The ZnO NPs exhibited excellent photocatalytic degradation of cationic (methylene blue), anionic (methyl orange), and nonionic (p-nitrophenol) dyes under sunlight exposure with photocatalytic degradation of 85.61%, 79.10%, and 89.95% respectively. Additionally, the nanoparticles displayed antimicrobial activity against Gram-positive and Gram-negative bacteria, and noteworthy antioxidant potential. The anti-inflammatory activity of the ZnO NPs, attributed to their ability to inhibit protein denaturation, was dose-dependent. Overall, our findings highlight the versatile properties of the greenly synthesized ZnO NPs, showcasing their potential in environmental remediation, and antimicrobial formulations, and as promising candidates for further exploration in the biomedical fields, including drug delivery and therapeutics.

Diffused sunlight assisted green synthesis of silver nanoparticles using Cotoneaster nummularia polar extract for antimicrobial and wound healing applications.

The current study reports the synthesis of silver nanoparticles (Ag NPs) using a polar extract of Cotoneaster nummularia leaves. Various analytical techniques, like UV-Vis spectrophotometry, FT-IR spectroscopy, XRD, SEM, and EDX were employed for characterisation. These techniques confirmed the stability of Ag NPs in solution and endorsed the interaction between different groups and Ag, crystal phase, surface morphology, and size of Ag NPs. UV-Vis spectrophotometer displayed SPR absorption bands ranging from 380 to 470 nm, characteristic of Ag NPs, within 1.0 h exposure to sunlight. XRD and SEM discovered the face-centered cubic crystals of Ag NPs with a 122.8 ± 1.1 nm average diameter. The bands at 525 cm-1 in FT-IR spectrum supported the development of Ag NPs. The Ag NPs showed antimicrobial potential against three pathogenic bacterial strains and two fungal strains. The wound healing results, as studied by tissue re-development and wound closure in rabbits were comparable to standard Sufre tulle® dressing.

A highly selective Hg2+ colorimetric sensor and antimicrobial agent based on green synthesized silver nanoparticles using Equisetum diffusum extract.

Plasmonic nanoparticles such as Ag have gained great interest in the biomedical domain and chemical analysis due to their unique optical properties. Herein, we report a simple, cost-effective, and highly selective colorimetric sensor of mercury(ii) based on E. diffusum (horsetail) extract-functionalized Ag nanoparticles (ED-AgNPs). The ED-AgNPs were synthesized by exploiting the coordination of Ag+ with the various functional groups of ED extract under sunlight exposure for only tens of seconds. ED-AgNPs (63 nm) were characterized using various techniques such as UV-vis, FTIR, DLS, SEM and EDX. FTIR spectra suggested the successful encapsulation of the AgNPs surface with ED extract and XRD confirmed its crystalline nature. This ED-AgNPs colorimetric sensor revealed remarkable selectivity towards Hg2+ in aqueous solution among other transition metal ions through a redox reaction mechanism. Besides, the sensor exhibited high sensitivity with rapid response and a detection limit of 70 nM. The sensor demonstrated feasibility for Hg(ii) detection in spiked tap and river water samples. In addition, the synthesized ED-AgNPs revealed enhanced antimicrobial activity with higher efficacy against the Gram-positive bacterium (L. monocytogenes with an inhibition zone of 18 mm) than the Gram-negative bacterium (E. coli with an inhibition zone of 10 mm). The simplicity and adaptability of this colorimetric sensor render it a promising candidate for on-site and point-of-care detection of heavy metal ions in diverse conditions.

Aconitum lycoctonum L. (Ranunculaceae) mediated biogenic synthesis of silver nanoparticles as potential antioxidant, anti-inflammatory, antimicrobial and antidiabetic agents.

In this study, a polar extract of Aconitum lycoctonum L. was used for the synthesis of silver nanoparticles (AgNPs), followed by their characterization using different techniques and evaluation of their potential as antioxidants, amylase inhibitors, anti-inflammatory and antibacterial agents. The formation of AgNPs was detected by a color change, from transparent to dark brown, within 15 min and a surface resonance peak at 460 nm in the UV-visible spectrum. The FTIR spectra confirmed the involvement of various biomolecules in the synthesis of AgNPs. The average diameter of these spherical AgNPs was 67 nm, as shown by the scanning electron micrograph. The inhibition zones showed that the synthesized nanoparticles inhibited the growth of Gram-positive and negative bacteria. FRAP and DPPH assays were used to demonstrate the antioxidant potential of AgNPs. The highest value of FRAP (50.47% AAE/mL) was detected at a concentration of 90 ppm and a DPPH scavenging activity of 69.63% GAE was detected at a concentration of 20 µg/mL of the synthesized AgNPs. 500 µg/mL of the synthesized AgNPs were quite efficient in causing 91.78% denaturation of ovalbumin. The AgNPs mediated by A. lycoctonum also showed an inhibitory effect on α-amylase. Therefore, AgNPs synthesized from A. lycoctonum may serve as potential candidates for antibacterial, antioxidant, anti-inflammatory, and antidiabetic agents.

Improved Photocatalytic and Antioxidant Activity of Olive Fruit Extract-Mediated ZnO Nanoparticles.

Photodegradation is an efficient strategy for the removal of organic pollutants from wastewater. Due to their distinct properties and extensive applications, semiconductor nanoparticles have emerged as promising photocatalysts. In this work, olive (Olea Europeae) fruit extract-based zinc oxide nanoparticles (ZnO@OFE NPs) were successfully biosynthesized using a one-pot sustainable method. The prepared ZnO NPs were systematically characterized using UV-Vis, FTIR, SEM, EDX and XRD and their photocatalytic and antioxidant activity was evaluated. SEM demonstrated the formation of spheroidal nanostructures (57 nm) of ZnO@OFE and the EDX analysis confirmed its composition. FTIR suggested the modification/capping of the NPs with functional groups of phytochemicals from the extract. The sharp XRD reflections revealed the crystalline nature of the pure ZnO NPs with the most stable hexagonal wurtzite phase. The photocatalytic activity of the synthesized catalysts was evaluated by measuring the degradation of methylene blue (MB) and methyl orange (MO) dyes under sunlight irradiation. Improved degradation efficiencies of 75% and 87% were achieved within only 180 min with photodegradation rate constant k of 0.008 and 0.013 min-1 for MB and MO, respectively. The mechanism of degradation was proposed. Additionally, ZnO@OFE NPs exhibited potent antioxidant activity against DPPH, hydroxyl, peroxide and superoxide radicals. Hence, ZnO@OFE NPs may have potential as a cost-effective and green photocatalyst for wastewater treatment.

Assessment of Attitudes and Intentions towards COVID-19 Vaccines and Associated Factors among General Populations of Pakistan: A Cross-Sectional Study.

OBJECTIVE: The goal of public health in combatting COVID-19 is to increase herd immunity. However, vaccine reluctance makes attaining herd immunity a worldwide challenge. This investigation aimed to identify negative and positive attitudes and intentions about COVID-19 vaccinations. METHODS: A cross-sectional online survey was conducted once free COVID-19 vaccines became available in Pakistan in 2021. 4392 Pakistanis aged 18 and older were surveyed from seven administrative units between 1 July and 30 August 2021. Online structured questionnaires were utilized to collect data using a simple sampling procedure. The questionnaires were divided into three major sections: sociodemographic, health factors, and attitudes toward COVID-19. RESULTS: The survey link was shared with approximately 4500 participants. 97.6%(4392) completed the survey once begun. Frequency, percentage and Chi-square tests were used to analyze statistical data. Most of the participants in the research were men (2703 (61.54%)), 3277 (74.61%) were aged 18-29 years, and 1824 (41.53%) were residents of the Khyber Pakhtunkhwa province. (18.69%) Respondents expressed COVID-19 vaccine hesitancy, whereas 36.66% of participants liked getting the Sinopharm and Sinovac vaccines and (35.84%) of participants preferred the Pfizer vaccine. A significant number of participants (38.05%) were concerned about the vaccine's unexpected side effects Thus, it is essential to realize that many participants were concerned about the vaccine's unexpected side effects. CONCLUSIONS: The overall high level of concern about the unforeseen side effects of COVID-19 vaccines, as well as widespread vaccine hesitancy among Pakistani populations and its predictors, should be taken into account if public health intervention campaigns in Pakistan are changing negative attitudes and improving compliance with regard to COVID-19 vaccines.