1. Sensitive colorimetric aptasensor based on g-C3N4@Cu2O composites for detection of Salmonella typhimurium in food and water
- Author
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Azam Bagheri Pebdeni, Morteza Hosseini, Foad Salehnia, Hazha Omar Othman, and Afrooz Tarokh
- Subjects
Detection limit ,Copper oxide ,Salmonella ,Chromatography ,Aptamer ,010401 analytical chemistry ,Graphitic carbon nitride ,02 engineering and technology ,021001 nanoscience & nanotechnology ,medicine.disease_cause ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Catalysis ,chemistry.chemical_compound ,chemistry ,medicine ,Detection performance ,0210 nano-technology ,Hydrogen peroxide - Abstract
A new colorimetric aptasensor equipped with a novel composite of graphitic carbon nitride (g-C3N4) nanosheets and copper oxide(I) (Cu2O) nanocrystals is presented for Salmonella typhimurium (S .typhimurium). The dual-purpose structure of this composite simultaneously contributes to superb peroxidase-like activity and interaction with a label-free aptamer. Although g-C3N4@Cu2O effectively creates a visible blue color following the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in presence of hydrogen peroxide (H2O2), this catalytic activity of the composite severely decreases after the interaction with aptamers. In the presence of S. typhimurium in sample, aptamers bound to their specific target. Subsequently, g-C3N4@Cu2O catalytic activity was enhanced in proportion to S. typhimurium concentration. Under optimized conditions, this aptasensor exhibited an excellent detection performance in a range from 1.5 × 101 to 1.5 × 105 CFU/ml, with a detection limit of 15 CFU/ml. Besides, portable detection of S. typhimurium by paper-based model of this method operated successfully in just 6 min. Analysis of spiked milk samples revealed high potential of this method as a sensitive, rapid, and label-free promising tool for S. typhimurium detection.
- Published
- 2021