Rapid, efficient and green method of Pd nanoparticles (PdNPs) synthesis on TEMPO-oxidized cellulose nanofibril (TCNF) is demonstrated here. The nanohybrid (PdNPs/TCNF) exhibited peroxidase and oxidase-like activities evident by the oxidation of three chromogenic substrates. Enzyme kinetic studies using 3,3',5,5'-Tetramethylbenzidine (TMB) oxidation uncovered the excellent kinetic parameters (low K and high V) and good specific activities of 215 U/g and 107 U/g for peroxidase and oxidase-like activities, respectively. A colorimetric assay for ascorbic acid (AA) detection is proposed based on its ability to reduce oxidized TMB to its colorless form. However, presence of nanozyme caused re-oxidation of TMB to its blue colored form within few minutes resulting in time limitation and inaccurate detection. Thanks to the film forming nature of TCNF; this limitation was overcome by employing PdNPs/TCNF film strips that can be easily removed before AA addition. The assay allowed AA detection in the linear range of 0.25-10 μM with a detection limit of 0.039 μM. The results of AA detection in commercial beverages and vitamin C tablets are matching with the specified values. Further the nanozyme exhibited high tolerance to pH (2-10) and temperature (up to 80 °C) and good recyclability for five cycles.
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http://dx.doi.org/10.1016/j.ijbiomac.2023.123657 | DOI Listing |
Talanta
December 2024
NanoBiosensors and Biodevices Lab, School of Medical Science and Technology, Indian Institute of Technology Kharagpur, West Bengal, 721302, India. Electronic address:
This work presents a robust strategy for quantifying overlapping electrochemical signatures originating from complex mixtures and real human plasma samples using nickel-based electrochemical sensors and machine learning (ML). This strategy enables the detection of a panel of analytes without being limited by the selectivity of the transducer material and leaving accommodation of interference analysis to ML models. Here, we fabricated a non-enzymatic electrochemical sensor for L-lactic acid detection in complex mixtures and human plasma samples using nickel oxide (NiO) nanoparticle-modified glassy carbon electrodes (GCE).
View Article and Find Full Text PDFJ Food Drug Anal
December 2024
Zhenjiang College, Zhenjiang, 212000, PR China.
Ascorbic acid (AA) is used as a food additive for its antibacterial and antioxidant properties. However, excessive intake of AA is harmful to humans. Therefore, the detection of Fe and AA is generally recognized to be meaningful.
View Article and Find Full Text PDFBMC Plant Biol
January 2025
Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA.
Purpose: This study explored how exogenous silicon (Si) affects growth and salt resistance in maize.
Methods: The maize was cultivated in sand-filled pots, incorporating varied silicon and salt stress (NaCl) treatments. Silicon was applied at 0, 2, 4, 6, and 8 mM, and salt stress was induced using 0, 60 and120 mM concentrations.
Anal Chem
January 2025
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China.
Human cells generate a bulk of aldehydes during lipid peroxidation (LPO), influencing critical cellular processes, such as oxidative stress, protein modification, and DNA damage. Enals, highly reactive α,β-unsaturated aldehydic metabolites, are implicated in various human pathologies, especially neurodegenerative disorders, cancer, and cardiovascular diseases. Despite their importance, endogenous enals remain poorly characterized, primarily due to their instability and low abundance.
View Article and Find Full Text PDFLuminescence
January 2025
Pharmaceutical Chemistry Department, Faculty of Pharmacy, Misr International University, Cairo, Egypt.
Affordable and eco-friendly green spectrofluorometric (FL) methods can enhance the safety and cost-effectiveness of quality assurance and control in ascorbic acid (ASA) formulations. However, most current techniques for ASA analysis have faced challenges like complexity, delayed response times, low throughput, time-consuming procedures, and requirements for expensive equipment and hazardous chemicals for analyte modification. The study is aimed at producing natural carbon quantum dots (NACQDs) from pumpkin seed peels (PSPs), a natural waste material, using a rapid microwave-assisted method.
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