Whey peptide-encapsulated silver nanoparticles as a colorimetric and spectrophotometric probe for palladium(II)

Green Synthesis of Silver Nanoparticles Using Acacia ehrenbergiana Plant Cortex Extract for Efficient Removal of Rhodamine B Cationic Dye from Wastewater and the Evaluation of Antimicrobial Activity

Silver nanoparticles (Ag-NPs) exhibit vast potential in numerous applications, such as wastewater treatment and catalysis. In this study, we report the green synthesis of Ag-NPs using Acacia ehrenbergiana plant cortex extract to reduce cationic Rhodamine B (RhB) dye and for antibacterial and antifungal applications. The green synthesis of Ag-NPs involves three main phases: activation, growth, and termination. The shape and morphologies of the prepared Ag-NPs were studied through different analytical techniques. The results confirmed the successful preparation of Ag-NPs with a particle size distribution ranging from 1 to 40 nm. The Ag-NPs were used as a heterogeneous catalyst to reduce RhB dye from aqueous solutions in the presence of sodium borohydride (NaBH₄). The results showed that 96% of catalytic reduction can be accomplished within 32 min using 20 μL of 0.05% Ag-NPs aqueous suspension in 100 μL of 1 mM RhB solution, 2 mL of deionized water, and 1 mL of 10 mM NaBH₄ solution. The results followed a zero-order chemical kinetic (R² = 0.98) with reaction rate constant k as 0.059 mol L^-1 s^-1. Furthermore, the Ag-NPs were used as antibacterial and antifungal agents against 16 Gram-positive and Gram-negative bacteria as well as 1 fungus. The green synthesis of Ag-NPs is environmentally friendly and inexpensive, as well as yields highly stabilized nanoparticles by phytochemicals. The substantial results of catalytic reductions and antimicrobial activity reflect the novelty of the prepared Ag-NPs. These nanoparticles entrench the dye and effectively remove the microorganisms from polluted water.

Advances from conventional to real time detection of heavy metal(loid)s for water monitoring: An overview of biosensing applications

The rapid growth of the industrial sector has expedited the accumulation of heavy metal(loid)s in the environment at hazardous levels. The elements such as arsenic, lead, mercury, cadmium and chromium are lethal in terms of toxicity with severe health impacts. With issues like water scarcity, limitations in wastewater treatment, and costs pertaining to detection in environmental matrices; their rapid and selective detection for reuse of effluents is of the utmost priority. Biosensors are the futuristic tool for the accurate qualitative and quantitative analysis of a specific analyte and integrate biotechnology, microelectronics and nanotechnology to fabricate a miniaturized device without compromising the sensitivity, specificity and accuracy. The characteristic features of supporting matrix largely affect the biosensing ability of the device and incorporation of highly sensitive and durable metal organic frameworks (MOFs) are reported to enhance the efficiency of advanced biosensors. Electrochemical biosensors are among the most widely developed biosensors for the detection of heavy metal(loids), while direct electron transfer approach from the recognition element to the electrode has been found to decrease the chances of interference. This review provides an insight into the recent progress in biosensor technologies for the detection of prevalent heavy metal(loid)s; using advanced support systems such as functional metal-based nanomaterials, carbon nanotubes, quantum dots, screen printed electrodes, glass beads etc. The review also delves critically in comparison of various techno-economic studies and the latest advances in biosensor technology.

The Ameliorative Role of Eugenol against Silver Nanoparticles-Induced Hepatotoxicity in Male Wistar Rats

Background

Silver nanoparticles (AgNPs) utilization is becoming increasingly popular. The existing investigation evaluates the ameliorative impact of eugenol (Eug) against the toxic influences of AgNPs on rats' liver.

Methods

Sixty adult male rats were enrolled equally into control, Eug (100 mg kg⁻¹ orally), AgNPs-low dose (1 mg kg⁻¹ i.p), AgNPs-high dose (2 mg kg⁻¹ i.p), Eug + AgNPs-low dose (100 mg kg⁻¹ orally + 1 mg kg⁻¹ i.p), and Eug + AgNPs high dose (100 mg kg⁻¹ orally + 2 mg kg⁻¹ i.p). All the groups were treated daily for 30 days, subsequently serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total protein, total albumin, lactate dehydrogenase (LDH), total oxidative capacity (TOC), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), total antioxidant capacity (TAC), and interleukin 6 (IL-6) levels were measured; hepatic tissues superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and glutathione peroxidase (GPx) levels were evaluated; histopathology and histomorphometry were documented in the liver of all groups; and Bcl-2, P53, Caspase-3, and TNF-α reactive proteins were also immunohistochemically detected.

Results

AgNPs significantly triggered oxidative stress in hepatic tissues, characterized by elevated levels of AST, ALT, ALP, LDH, TOC, MDA, TNF-α, and IL-6 correlating with considerable decline in total protein, total albumin, TAC, SOD, CAT, GSH, and GPx. These changes were paralleled with histopathological alterations remarkable by devastation of the ordinary hepatic structure, with decrease in the numbers of normal hepatocytes, elevation in the numbers of necrotic hepatocytes, periportal and centrilobular inflammatory cells, deteriorated Kupffer cells, and dilated/congested central and portal veins. Alongside, a marked diminution in Bcl-2 immunoreactivity and a significant elevation in P53, Caspase-3, and TNF-α immunoreactivities were recorded. Supplementation of AgNPs-treated animals with Eug reversed most of the biochemical, histopathological, and immunohistochemical changes.

Conclusion

This study proposed that Eug has an ameliorative effect against AgNPs-induced hepatotoxicity.