ascorbic-acid and thionine

In this work, a multiplexed electrochemical aptasensor based on mixed valence Ce-MOF was constructed for the simultaneous determination of malathion and chlorpyrifos. Firstly, Ce(III, IV)-MOF materials with many catalytic sites were synthesized and characterized by SEM, TEM, XPS, FT-IR, XRD, and UV-Vis. Then, the chlorpyrifos and malathion signal markers based on Ce(III, IV)-MOF were prepared using thionine (Thi) and ferrocene (Fc) used as the electrochemical probe. The electrochemical signal was amplified by the reduction of thionine catalyzed by the spontaneous cycle of Ce(III, IV) in Ce(III, IV)-MOF skeleton and the reduction of ferrocene catalyzed by ascorbic acid (AA) in solution. The detection of the two targets did not interfere with each other, and the quantitative detection was realized with high sensitivity. The detection range of chlorpyrifos and malathion were 1.0 μM ∼ 0.1 pM, and the detection limits of chlorpyrifos and malathion were 0.038 and 0.045 pM (S/N = 3), respectively. The sensor provided a new idea for the simultaneous determination of multi-component and had a high application prospect in the field of food safety in the future.

Topics: Aptamers, Nucleotide; Ascorbic Acid; Biosensing Techniques; Chlorpyrifos; Electrochemical Techniques; Ferrous Compounds; Limit of Detection; Malathion; Metal-Organic Frameworks; Metallocenes; Phenothiazines; Spectroscopy, Fourier Transform Infrared

Topics: Ascorbic Acid; Cell Nucleus; Cross-Linking Reagents; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Glutathione Transferase; HeLa Cells; Humans; Introns; Ligands; Methylene Blue; Phenothiazines; Recombinant Fusion Proteins; RNA Splicing; RNA, Double-Stranded; Spliceosomes; Ultraviolet Rays

The photooxidation of ascorbic acid sensitized by Thionine Blue was studied. The Leucothionine Blue formed during the reaction is highly fluorescent. A flow injection method using merging zones is proposed for the determination of ascorbic acid over a concentration range from 8 x 10(-7) to 5 x 10(-5) mol l-1 with a throughout of 80 samples per h. The method was used for the simple and rapid determination of ascorbic acid in pharmaceuticals, fruit juices and soft drinks.

Topics: Ascorbic Acid; Flow Injection Analysis; Light; Oxidation-Reduction; Phenothiazines

Topics: Ascorbic Acid; Coloring Agents; Humans; Phenothiazines; Vitamins