کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5131667 | 1491319 | 2017 | 6 صفحه PDF | دانلود رایگان |
MicroRNAs (miRNAs) have key roles in gene expression and can be employed as biomarkers for early diagnosis of various diseases, especially cancers. Detection of miRNAs remains challenging and often requires detection platforms. Here, a horseradish peroxidase (HRP)-assisted hybridization chain reaction (HCR) for colorimetric detection of miR-155 was described. In the presence of target miRNA, the capture probe immobilized on the microplate sandwiched the target miR-155 with the 3â² end of the reporter probe. Another exposed part of the RP at the 5'end triggered HCR producing double-stranded DNA polymers with multiple fluorescein isothiocyanates (FITC) for signal amplification. Finally, multiple HRP molecules were immobilized onto the long-range DNA nanostructures through FITC/anti-FITC monoclonal antibody interactions on the microplate for visualization by tetramethylbenzidine/H2O2 system and the colorless substrate turned into the blue product. To obtain accurate data, the absorbance at 450Â nm was calculated by microplate reader. The detection limit was 31.8Â fM (3.18Â amol). Furthermore, this biosensor showed high specificity and was able to discriminate sharply between target miRNA and mismatched sequences. And this approach could be easily applied to the detection of miR-155 in serum sample, thereby ascribing it for a wide application.
Journal: Analytical Biochemistry - Volume 528, 1 July 2017, Pages 7-12