Current Nanomaterials - Volume 10, Issue 2, 2025

Because of its numerous advantages, biochar has been widely used to remove contaminants from aqueous media for several years. However, unmodified biochar often exhibits low sorption capacity. Therefore, various nano-sized metal oxides have been developed to modify biochar and improve its ability to remove impurities.

This review aims to provide information on preparing and applying biochar loaded with nano-sized metal oxides to treat pollutants in water samples.

Raw biochar has limited applicability/capacity for certain pollutants, such as inorganic anions. However, modification with metal oxides improved removal performance, sorption capacity, and selectivity.

Biochar loaded with metal oxides is believed to be an environmentally friendly alternative for treating polluted water. Selective sorbents with high capacity and fast kinetics towards undesirable solutes can be produced using suitable metal oxides. The sorbent can remove pollutants from solutions with a high removal rate.

Nanosensors are one of the most recent technologies obtained from the nanoworld. They have enhanced properties with potential applications in a wide spectrum of sectors. They exhibit exceptional properties in temperature monitoring, hazardous gas and vapor detection, humidity detection, as well as pathogens, toxins, and chemical contaminant detection. Among various nanosensor applications, one of the most recent usages of nanosensor technology is in logistics and supply chain management (SCM).

This study aims at investigating the potential of nanosensor technology from logistics & SCM perspective, and specifically questions how can this technology contribute to food supply chains.

A systematic comprehensive literature review was conducted with the keywords: nanosensors & logistics, nanosensors & supply chain, nanosensors & smart packaging, and nanosensors & food logistics for the date range 2001-2022, covering a broad set of references. Findings revealed that nanosensors have significant potential in providing smart packaging, and improving traceability and visibility across all the logistics and SCM processes including end-to-end transportation and storage activities.

Hybrids of different types of nanosensors with the existing material identification systems provide new levels of traceability and visibility in SCM, enabling accurate tracking of a variety of parameters. The study has shown that the intersection of nanotechnology and logistics & SCM domains is still immature.

This intersection is especially critical for food supply chains for meeting their special traceability requirements, and for serving food safety and organic food traceability across all stages of logistics.

The present work shows the effect of Bentonite Clay (BC) on the biodegradation behavior of Poly Vinyl Alcohol (PVA)/Banana Peel Nano Crystals (BPNC) composite films.

Biodegradation studies were conducted using soil burial and bacterial degradation method. The prepared composite films were characterized by scanning electron microscopy.

Biodegradation studies reported that the composite films were more degradable in bacterial environment as compared to natural soil burial. The addition of Bentonite Clay (BC) had negative effect on degradation rate of composite films.

PVA/BPNC/BC composite film showed less weight loss (%) as compared to PVA/BPNC composite films because BC had stabilizing effect against the microbial attack which prevents biodegradation.

Foodborne pathogenic bacteria continue to become a global concern despite the advancements in food packaging technology. Silver nanoparticles (AgNPs) are widely studied in the field as they exhibit desirable inhibitory properties against foodborne pathogens. AgNPs are conventionally synthesized by toxic chemical and physical means; hence, there is a need to seek environmentally safe alternative routes for producing AgNPs.

The study aimed to synthesize AgNPs using bignay (Antidesma bunius) leaf extract and assess its antimicrobial activity against the common foodborne pathogens S. aureus and E. coli.

Bignay leaf extract was characterized using total phenolic content (TPC) assay and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. AgNPs were produced under optimized pH, temperature, and incubation time and were characterized using UV-Vis spectroscopy, Fourier Transform Infrared spectroscopy, and Transmission Electron Microscopy. The antimicrobial activity of AgNPs was evaluated against S. aureus and E. coli using the Resazurin Microtiter Assay (REMA).

Bignay leaf extract exhibited a total phenolic content of 0.315 ± 0.015 mg GAE/mg extract and an IC50 of 36.36 ± 0.003 μg/mL, which suggests its good reducing properties. The AgNPs synthesized under reaction conditions of pH 7, 45 ºC, and 30 min showed SPR peaks in the range of 412-426 nm. Particles were spherical with an average size of 23.72 ± 7.30 nm. FTIR analysis revealed that the phenolic compounds in the extract capped the resulting nanoparticles. AgNPs demonstrated superior inhibitory activity against S. aureus and E. coli with MIC90 values of 2.90 ± 0.03 and 3.08 ± 0.004 μg/mL, respectively.

The study was able to develop a green approach for the synthesis of AgNPs with antibacterial properties using bignay leaf extract.

Antibiotic resistance among pathogens has grown to be a major concern for the health of people around the world. One of the main subgroups of troublesome multidrug-resistant bacteria that has recently undergone rapid evolution is Methicillin-resistant Staphylococcus aureus (MRSA).

In this study, silver nanoparticles were synthesized using an aqueous extract of Bridelia ferruginea leaves. The methicillin-resistant S. aureus was used to test the antibacterial properties of the produced Bridelia ferruginea-derived silver nanoparticles. These nanoparticles were characterized using XRD, UV-vis spectroscopy, FTIR, and SEM.

The antibacterial activity of the silver nanoparticles was improved at doses of 50, 100, and 150 ug/ml, with mean zones of inhibition (ZOI) of 13.0, 16.4, and 17.4 mm (SD1). When combined with erythromycin medicines, silver nanoparticles showed significant antibacterial efficiency compared to when used alone. The ZOI was 23 mm at 150 ug/mL, compared to 21 mm at 50 and 100 ug/mL. At P=0.06, the outcomes were statistically significant.

This established that the antibacterial impact of combining antibiotics with AgNPs is enhanced. The current work showed that biosynthesized B. ferruginea silver nanoparticles (BF-AgNPs) were effective in vitro.

Soil bacteria that synthesize varying metallic NPs are underreported, even though there is a promising mechanism in the bio-reduction of gold salts and the synthesis of gold nanoparticles by different bacterial species.

This study aimed to explore the ancillary potential of some soil microbes obtained from a metal fabricating workshop for gold nanoparticles (AuNPs) synthesis.

To evaluate the usefulness of these soil microbes, 1 mM chloroauric acid (HAuCl4.4H2O) was bio-reduced using the wet biomass of these bacterial cells and characterized with UV-Vis spectrophotometer, Fourier Transform Infra-red (FTIR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), and X-ray Diffractometer (XRD).

Findings from this study showed that the studied bacterial isolates synthesized AuNPs with absorbance peaks within the range of 500 and 600 nm. The FTIR analysis showed the involvement of O-H, N-H, and C=O stretch of alcohol, amine, and amide groups, respectively. The SEM images analyzed with Image J reported a mean area size between 17-184 nm. The EDX showed Klebsiella africana (C11), and Bacillus subtilis (A12) had the lowest (7.32%) and highest (51.26%) weight percentages of AuNPs, respectively.

Gold nanoparticles have been found most appropriate for several novel applications, and this work has provided further understanding of the capacity of naturally occurring bacteria to be non-selective in the bio-reduction of gold salts, hence expanding their potential uses.

The aim of this study is to enhance the solubility of Abm by loading it onto a chitosan (CS) polymer.

Polymer nanoparticle (NP) and Abm-CSNPs nanocomposites were prepared. Minitab 18 software was used to design 18 run samples to study the effects of CS, tripolyphosphate, and pH as independent variables on the loading efficiency and particle size (dependent variable). The response surface methodology (RSM) was also used to determine how the variables affected the response. The graphical analysis used surface plots, main effects plots, contour plots, and interaction graphs. The study includes F values, p values, variance inflation factors (VIFs), adjusted sums of square (Adj SSs), adjusted mean squares (Adj MSs) and square error of the coefficient (SE Coef). The carriers and loaded samples were also examined using the results of tests, including Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Furthermore, the release of Abm from Abm-CSNPs nanocomposite was studied in vitro.

The results revealed an ability to produce particle sizes ranging from (168-192) nm and loading efficiencies from (56.7-62.1).

Abm-CSNPs nanocomposite may be used as an alternative drug delivery system for Abm to increase the release time of Abm to 1400 minutes.