ABSTRACT
Here, we developed a copper sulfate (CuSO4)-initiated diphenylamine (DPA)-based colorimetric strategy coupled with loop-mediated isothermal amplification (LAMP) for rapid detection of two critical contagious pathogens, SARS-CoV-2 and Enterococcus faecium. To detect the DNA, acid hydrolysis of LAMP amplicons was executed, enabling the development of a blue color. In the LAMP amplicons, the bond between the purines and deoxyribose is extremely labile. It can be broken using 70% sulfuric acid followed by phosphate group elimination, which generates a highly active keto aldehyde group. CuSO4 plays an imperative role inducing DPA to rapidly react with the keto aldehyde group, producing an intense blue color within 5 min. Moreover, low quantities such as 103 copies μL-1 of SARS-CoV-2 RNA and 102 CFU mL-1 of E. faecium were successfully detected, revealing the advantages of the introduced method. To confirm practical applicability, multiplex detection of pathogens was performed using a foldable microdevice comprising reaction and detection zones. Various reactions such as DNA extraction, LAMP, and acid hydrolysis occurred in the reaction zone. Then, colorimetric reagents (DPA, CuSO4, and ethylene glycol) contained in the detection zone were mixed with the keto aldehyde group by simply folding the microdevice, which was heated at 65 °C for 5 min for colorimetric detection. An intense blue color was developed where the target DNA was present. These results indicate that the method proposed in this study is highly suitable for point-of-care applications, especially in resource-limited settings for the rapid detection of harmful pathogens. © 2023 American Chemical Society.
ABSTRACT
Here, we developed a copper sulfate (CuSO4)-initiated diphenylamine (DPA)-based colorimetric strategy coupled with loop-mediated isothermal amplification (LAMP) for rapid detection of two critical contagious pathogens, SARS-CoV-2 and Enterococcus faecium. To detect the DNA, acid hydrolysis of LAMP amplicons was executed, enabling the development of a blue color. In the LAMP amplicons, the bond between the purines and deoxyribose is extremely labile. It can be broken using 70% sulfuric acid followed by phosphate group elimination, which generates a highly active keto aldehyde group. CuSO4 plays an imperative role inducing DPA to rapidly react with the keto aldehyde group, producing an intense blue color within 5 min. Moreover, low quantities such as 103 copies μL-1 of SARS-CoV-2 RNA and 102 CFU mL-1 of E. faecium were successfully detected, revealing the advantages of the introduced method. To confirm practical applicability, multiplex detection of pathogens was performed using a foldable microdevice comprising reaction and detection zones. Various reactions such as DNA extraction, LAMP, and acid hydrolysis occurred in the reaction zone. Then, colorimetric reagents (DPA, CuSO4, and ethylene glycol) contained in the detection zone were mixed with the keto aldehyde group by simply folding the microdevice, which was heated at 65 °C for 5 min for colorimetric detection. An intense blue color was developed where the target DNA was present. These results indicate that the method proposed in this study is highly suitable for point-of-care applications, especially in resource-limited settings for the rapid detection of harmful pathogens. © 2023 American Chemical Society
ABSTRACT
Synthetic dyes have high fastness property and are stable under diverse conditions but over time it is seen that they are toxic to the environment and some are carcinogenic. Dyes derived from natural sources like tartrazine, cochineal red and sunset yellow may cause allergies when used alone or in a combination. Some of the colourants that had been approved by the Food and Drug Administration for use in various industries like food, pharmaceuticals, cosmetics are found to promote cancer. The purpose of the present study is to extract natural dyes from peel of fruits and vegetables, flowers and study the effect of different mordanting techniques (pre-mordanting, simultaneous mordanting, post-mordanting) on dyeing, The extracts were applied as direct dyes in the presence of mordants. Dyeing of cotton cloth was performed using extracts of Pomegranate peel (Punica granatum), Orange peel (Citrus sinensis), Marigold flowers (Tagetes erecta), Kidney bean seed coat (Phaseolus vulgaris). Colour strength, shade and fastness properties of the dyes have been tested. In pre and post mordanting, colour change was observed in Marigold and Pomegranate. In simultaneous mordanting, colour change was seen in Marigold, Pomegranate, Orange peel and Kidney bean. The obtained results have shown the dyeing potential of organic wastes as a source for cotton dyeing. Using waste as a source of natural dyes will help in reducing the environmental pollution. Our studies on market research for demand led us to the conclusion that there is demand for comfortable environmental friendly mask having increased functional properties.