Nanozymes have emerged as the forefront of research in analytical sensing due to their promising applications. In this study, we utilized polyethyleneimine (PEI)-modified Pichia pastoris residue to synthesize microbial-based palladium nanocomposites (Pd/MMR) through simple in-situ reduction methods. The dispersed active sites of Pd nanoparticles with a size of 2.12 ± 0.49 nm that were supported by microbial biomass provided excellent oxidative enzyme-mimicking activity to Pd/MMR. The catalytic mechanism of Pd/MMR involved the combined action of O, ·OH, and ·O, and possible reaction pathways and corresponding energy barriers were also revealed using DFT calculations. We also established a quantitative detection platform for nitrite using Pd/MMR. The platform could detect nitrite at concentrations of 10-300 μM with a detection limit of 0.27 μM, and was successfully applied to detect nitrite in real samples. These findings serve as a reference for the synthesis and application of metal nanocomposites using microorganisms.
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http://dx.doi.org/10.1016/j.foodchem.2023.137422 | DOI Listing |
Heliyon
January 2025
Environmental Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
In this study, a Cu@Ag core-shell was synthesized using a co-precipitation method. To create a new electrochemical sensor, a Cu@Ag core-shell with conductive polymers such as polyalizarin yellow R (PA) and Nafion (Nf) was immobilized on the surface of a glassy carbon electrode (Cu@Ag-Nf/PA/GCE). X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR) techniques were employed to characterize the Cu@Ag-Nf/PA/GCE.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, 130000, PR China. Electronic address:
Nitrite is widely used as a food additive, and it is of great significance to realize accurate detection of nitrite for food safety. Electrochemical technique is characterized by simple operation and portability, which enables rapid and accurate detection. The key factors affecting the nitrite detection performance are the electrocatalytic activity and interfacial electron transfer efficiency of the electrode.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China. Electronic address:
Background: The rapid and sensitive detection of nitrite is important to human health protection due to its carcinogenic and teratogenic risks with excessive intake. The Griess assay is widely applied for the design of nitrite detection system. However, its relatively slow reaction kinetics and sole colorimetry mode might limit it's the sensitivity and practical application.
View Article and Find Full Text PDFAppl Biochem Biotechnol
January 2025
Department of Biotechnology-CBS, Metropolitan Autonomous University Iztapalapa, Av. Ferrocarril San Rafael Atlixco 186, 09310, Mexico City, Mexico.
The presence of antibiotics in wastewater discharges significantly affects the environment, mainly due to the generation of bacterial populations with multiple antibiotic resistances. The cometabolic capacity of nitrifying sludge to simultaneously remove ammonium (NH) and emerging organic contaminants (EOCs), including antibiotics, has been reported. In the present study, the removal capacity of 50 mg ampicillin (AMP)/L by nitrifying cultures associated with biosorption and biotransformation processes was evaluated in a sequencing batch reactor (SBR) system.
View Article and Find Full Text PDFMikrochim Acta
January 2025
School of Material Science and Engineering, Henan University of Technology Zhengzhou, Henan, 450001, China.
A simple, fast, and cost-effective colorimetric nitrite (NO) sensor based on ZIF-67-derived CoO nanocomposite (ZCo-2 NC) structure has been developed. The prepared colorimetric sensor (ZCo-2 NC) was employed to sensitively detect NO in drinking water system by the exhibition of promising peroxidase-mimicking nanozyme-like features. The sensor manifest well-determined sensing response with excellent linear and wide range of NO sensitivity (0.
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