کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1163062 1490920 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Three different signal amplification strategies for the impedimetric sandwich detection of thrombin
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Three different signal amplification strategies for the impedimetric sandwich detection of thrombin
چکیده انگلیسی


• Aptasensor to detect thrombin reaching the femtomolar level.
• Biosensing protocol employs two thrombin aptamers in a sandwich capture scheme.
• Use of second biotinylated aptamer allows many amplification and detection variants.
• Precipitation reaction provides the highest signal amplification of ca. 3 times.
• Double recognition event improves remarkably selectivity for thrombin detection.

In this work, we report a comparative study on three highly specific amplification strategies for the ultrasensitive detection of thrombin with the use of aptamer sandwich protocol. The protocol consisted on the use of a first thrombin aptamer immobilized on the electrode surface, the recognition of thrombin protein, and the reaction with a second biotinylated thrombin aptamer forming the sandwich. Through the exposed biotin end, three variants have been tested to amplify the electrochemical impedance signal. The strategies included (a) silver enhancement treatment, (b) gold enhancement treatment and (c) insoluble product produced by the combination of the enzyme horseradish peroxidase (HRP) and 3-amino-9-ethylcarbazole (AEC). The properties of the sensing surface were probed by electrochemical impedance measurements in the presence of the ferrocyanide/ferricyanide redox marker. Insoluble product strategy and silver enhancement treatment resulted in the lowest detection limit (0.3 pM), while gold enhancement method resulted in the highest reproducibility, 8.8% RSD at the pM thrombin concentration levels. Results of silver and gold enhancement treatment also permitted direct inspection by scanning electron microscopy (SEM).

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Analytica Chimica Acta - Volume 912, 17 March 2016, Pages 117–124
نویسندگان
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