بهبود فرآیند واکنش در سطح ایمونوسنسور با به‌کارگیری فلوی AC الکتروترمال

نویسنده

دانشکده مهندسی برق - دانشگاه بناب

چکیده

در سال‌های اخیر ایمونوسنسورها از مزایای مجتمع‌سازی و مینیاتوری کردن در میکروسیالات بهره گرفته‌اند. به‌منظور فراهم نمودن: الف) انتقال جرم در ایمونوسنسور ب) پروفایل فلوهای چرخشی کارآمد در اطراف سنسور و ج) افزایش بازده تغلیظ سنسور؛ در این پژوهش یک فلوی AC الکتروترمال کارآمد در داخل میکروکانال بکار برده شد. فلوی چرخشی پیشنهادی پدیده انتقال آنتی‌ژن (موجود در بافر) را به آنتی‌بادی (موجود در فاز ساکن) بهبود می‌بخشد و باعث فراهم شدن پروسسه ترکیب بین آنتی‌بادی و آنتی‌ژن می‌شود. فیزیک‌های حاکم جهت ایجاد فلوی AC الکتروترمال و انجام پروسه تغلیط بر روی سطح سنسور شامل معادلات کوپل شده (الکترواستاتیک، مکانیک سیالات، حرارت، انتقال جرم گونه‌ها و معادله واکنش بین آنتی بادی و آنتی ژن) هستند که با روش المان محدود مورد تحلیل قرار گرفت. شبیه‌سازی در حالت‌های پسیو (بدون فلوی چرخشی) و اکتیو (با فلوی چرخشی)  مورد بررسی قرار گرفت و محل قرارگیری سنسور بهینه‌سازی شد. مطابق نتایج به دست آمده، فلو AC الکتروترمال (ولتاژ 10 ولت، فرکانس 300 کیلوهرتز) منجر به ایجاد فلوی چرخشی در اطراف سنسور می‌گردد و 5 ثانیه پس از بارگذاری آنالیت، واکنش اتصال آنتی‌بادی به آنتی‌ژن 10 مرتبه افزایش می‌یابد. ساختار تغلیظ‌گر پیشنهادی برای سیستم‌های ایمونوسنسور مبتنی بر میکروسیالات با مشخصه عدد دامکهلر بزرگ و عدد پکلت کوچک، بسیار کارآمد است.

کلیدواژه‌ها


عنوان مقاله [English]

Immunosensor Surface Reaction Enhancment by Applying an AC Electrotherm Flow

نویسنده [English]

  • R. Hadjiaghaie Vafaie
Faculty of Electrical Engineering, University of Bonab, Bonab, Iran
چکیده [English]

Immunosensors have recently benefited from integration and miniaturization in microfluidic chips. In this research, an efficient AC electrothermal flow have been employed inside a microchannel in order to provide b) circular vorticities near the immunosensor, a) mass transfer effect, c) immunosensor concentrating enhancment. Our proposed stirring effect enhances the transport of suspended antigen to the immobilized antibody and provides more binding opportunity. The governing equations for fluid motion and immunosensor concentrating process are multiphysic coupled electric field, fluid flow, temperature field, diluted species transport and also binding reactions equations. Both the paasive (without stirring flow) and active (with stirring flow) Ab-Ag binding reaction has been numerically studied by Finite-Element Method, and the sensor location is optimized. Based on the results, the AC electrothermal swirling flow (applied ac field 10 Volt and operating frequency 200 kHz) applied to the electrodes and the surface reaction increases by the factor of 10 after 5 seconds of sample loading. The system is highly efficient for high conducive fluid mediums. Results revealed that our proposed microfluidic based reaction enhancement method is of interest in high Damkohle immunoassays and low Peclet number systems

کلیدواژه‌ها [English]

  • Micro-Electro-Mechanical-Systems
  • Microfluidic
  • AC Electrothermal flow
  • Immunosensor
  • Concentrating
  • Electrokinetic
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