RESUMO
Methods for sequence-specific microRNA (miRNA) analysis are crucial for miRNA research and guiding nursing strategies. We have devised a colorimetric technique for detecting miRNA using a dumbbell probe-based polymerase/endonuclease assisted chain displacement, along with silver ions (Ag+) aptamer assisted color reaction. The suggested approach enables precise measurement of miRNA-21 within the concentration range of 100 fM-5 nM, with a low detection limit of 45.32 fM. Additionally, it exhibits exceptional capability in distinguishing variations at the level of individual nucleotides. Furthermore, the detection technique may be utilized to precisely measure the amount of miRNA-21 in serum samples, demonstrating a high level of concordance with the findings obtained from a commercially available miRNA detection kit.
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RESUMO
UNLABELLED: Due to the potential toxic effects of the nitrofuran family of antibiotics, their use in animals in the food industry has raised health concerns. This study was aimed to develop a lateral flow assay (LFA) based on competitive format for the detection of 1-aminohydantoin (AHD) in meat samples. The assay could be completed in 1 min and detected AHDs derivates (CPAHD) at 3 ng/mL, equivalent to 1.40 ng/mL of AHD, which was much lower than that reported in the literature by similar method. The antibody showed no cross-reactivity with a panel of more than 10 nitrofuran analogs except for nitrofurantoin at a high concentration. The test strip was stable at room temperature for up to 8 wk or at 37 °C for 4 wk. Parallel analyses of meat samples with LFA and enzyme-linked immunosorbent assay (ELISA) obtained data in good agreement. This developed gold nanoparticle based LFA had a good specificity, sensitivity, stability, and reliability. It was potentially suitable for on-the-spot large-scale screening of meat samples, and even more other applications. PRACTICAL APPLICATION: Nitrofurantoin is one of antibiotics of the nitrofuran family, which has been used not only to prevent and treat diseases, but also to promote growth in animals. However, concerning the carcinogenicity of the metabolite of nitrofurantoin (AHD), a new fast and convenient method for monitoring AHD should be established. We describe the development of a new test assay for rapid screening of meat samples.
