Photocatalytic activity of green synthesized cadmium sulfide quantum dots on the removal of RhB dye and its cytotoxicity and antibacterial studies

Broad-spectrum nano-bactericide utilizing antimicrobial peptides and bimetallic Cu-Ag nanoparticles anchored onto multiwalled carbon nanotubes for sustained protection against persistent bacterial pathogens in crops

Worldwide crop yields are threatened by persistent pathogenic bacteria that cause significant damage and jeopardize global food security. Chemical pesticides have shown limited effectiveness in protecting crops from severe yield loss. To address this obstacle, there is a growing need to develop environmentally friendly bactericides with broad-spectrum and sustained protection against persistent crop pathogens. Here, we present a method for preparing a nanocomposite that combines antimicrobial peptides (AMPs) and bimetallic Cu-Ag nanoparticles anchored onto multiwalled carbon nanotubes (MWCNTs). The nanocomposite exhibited dual antibacterial activity by disrupting bacterial cell membranes and splicing nucleic acids. By functionalizing MWCNTs with small AMPs (sAMPs), we achieved enhanced stability and penetration of the nanocomposite, and improved loading capacity of the Cu-Ag nanoparticles. The synthesized MWCNTs&CuNCs@AgNPs@P nanocomposites demonstrated broad-spectrum lethality against both Gram-positive and Gram-negative bacterial pathogens. Glasshouse pot trials confirmed the efficacy of the nanocomposites in protecting rice crops against bacterial leaf blight and tomato crops against bacterial wilt. These findings highlight the excellent antibacterial properties of the MWCNTs&CuNCs@AgNPs@P nanocomposite and its potential to replace chemical pesticides, offering significant advantages for agricultural applications.

Photocatalytic chitosan-based bactericidal films incorporated with WO3/AgBr/Ag and activated carbon for ethylene removal and application to banana preservation

Ethylene (C2H4) and pathogenic microorganisms are the two major causes of the deterioration of postharvest fruits and vegetables (F&V). Hence, the development of active packaging with C2H4 scavenging and bactericidal activities is urgently desirable. Herein, a novel photocatalytic active film (CS-PC-AC) is developed for banana preservation by incorporating WO3/AgBr/Ag photocatalyst (PC) and activated carbon (AC) into chitosan (CS). The fabricated PC is a ternary Z-scheme heterojunction and its high photocatalytic activity is achieved by the bridge of Ag between WO3 and AgBr through rapid transfer and separation of photogenerated electrons and holes. AC plays an indispensable role in the photocatalytic reaction through molecule adsorption and transport. PC and AC are hydrogen bonded with chitosan and their incorporation has slight effect on film's thermal stability but decreases the film's mechanical and barrier properties to some extent. CS-PC-AC exhibits strong bactericidal activity (killing ~100 % of Escherichia coli and Staphylococcus aureus within 3 h) and good C2H4 scavenging activity (C2H4 scavenging rate of 49 ± 2 %) under visible light irradiation, which can extend the banana shelf-life by at least 50 % at 25 °C. These results indicate the good perspective of CS-PC-AC in the delay of the deterioration of postharvest F&V.

Bio-engineered sensing of Atrazine by green CdS quantum dots: Evidence from electrochemical studies and DFT simulations

The present investigation reports a comprehensible and responsive strategy for identifying atrazine in several conditions using an extensive electrochemical method. CdS Quantum dots were synthesized via a greener approach, and their formation was endorsed by numerous characterization techniques such as FTIR, SEM, Raman, UV-Vis, and XRD. Owing to the splendid electrocatalytic behavior, Green CdS quantum dots (QDs) of crystallite size ∼2 nm was opted as the sensor material and were, therefore, incorporated on the bare carbon paste electrode's surface. The developed sensor demonstrated an impressive outcome for atrazine sensing accompanied by superior selectivity and sensitivity. The lower detection limit (LLOD) of 0.53 μM was attained using the developed sensor in a linear concentration range of 10-100 μM. Furthermore, the practical pertinence of the developed sensor was examined on distilled water, wastewater, and fresh liquid milk, resulting in a tremendous retrieval of atrazine (91.33-99.8%).