کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1242567 1495782 2016 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Sensitive analytical performance of folding based biosensor using methylene blue tagged aptamers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Sensitive analytical performance of folding based biosensor using methylene blue tagged aptamers
چکیده انگلیسی


• First time demonstrated a redox probe labeled aptamer coupling using spacers.
• Easy to perform using click chemistry.
• First report of folding based Aptasensor for OTA in cocoa.

This work demonstrates the development of a folding based electrochemical aptasensor using methylene blue (MB) tagged anti-Ochratoxin A (OTA) aptamers. Different aptamer coupling strategies were tested using Hexamethylenediamine, polyethylene glycol, simple adsorption and diazonium coupling mechanism. The best sensitivity was recorded by oxidation of amines using hexamethylenediamine (HDMA) on screen printed carbon electrode (SPCE). To achieve the direct detection of OTA, aptamer conjugated redox probe was used and detection was demonstrated based on the conformational changes in aptamer structure upon OTA sensing. Signaling in this class of sensors arises from changes in electron transfer efficiency upon target-induced changes in the conformation/flexibility of the aptamer probe. These changes can be readily recorded electrochemically. The developed aptasensor is unique in its own mechanism as redox probe tagged aptamer coupling such as MB has never been tried to immobilize using long carbon chain spacers as, addition of spacers would provide more sensitive detection methods. A good dynamic range 0.01–5 ng/ml was obtained for OTA with Limit of detection (LOD) 0.01 ng/ml and Limit of quantification (LOQ) of 0.03 ng/ml respectively. The good reproducibility was recorded with RSD% of 3.75. The obtained straight line equation was y=0.4035x+0.90311, r=0.9976. We believe that the sensor design guidelines outlined here represents a general strategy for developing new folding-based electrochemical aptasensors. The developed aptasensor was extended to screen cocoa samples for OTA contamination. The cocoa samples were extracted and purified using molecular imprinted polymer (MIP) columns. The aptasensor displayed good recovery values in the range 84–85% thus, exhibited the effectiveness of proposed aptasensor for such complex matrices.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Talanta - Volume 153, 1 June 2016, Pages 138–144
نویسندگان
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