MEMS Biosensor Array for Biochemical and Clinical Diagnostics

量热法是分析生化反应的一种非常通用和有效的研究工具，能够提供生化反应的连续定量分析，并具有出色的操作稳定性。作为时间或反应物浓度的函数，连续跟踪生化反应进程的能力有许多研究和临床应用，具有深远的后果。然而，量热生物分析主要受到设备的高成本、响应时间慢和笨重性质的阻碍。为了解决这些局限性，提出了一种新型的量热生物传感器，它是通过将聚合物微反应室集成到MEMS薄膜独立式微热电堆传感器上来实现的。热电堆将被制造在独立式微机械结构上，例如将冷结放置在硅片(边缘)主体上的悬臂梁上，以及将热结放置在独立式结构上。一个基于聚合物的反应室将被集成在热电堆的热连接的正上方。边缘的大热质量和良好的导热性能使冷结保持在室温，而不受约束的悬臂梁尖端由于反应热而温度升高。用特定的固定化酶包覆热连接，通过只催化相应分析物的反应来提供选择性。该传感器还将用于准确测量反应物的比热和热扩散率。这些热物性的实时监测将为分析生化反应的进展提供一个独立的工具。

Calorimetry is a very versatile and effective investigative tool for analyzing biochemical reactions and is capable of providing continuous quantitative assays of biochemical reactions with exceptional operational stability. The ability to follow the progress of a biochemical reaction continuously as a function of time or reactant concentration has many research and clinical applications with far reaching consequences. However, calorimetric bioanalysis has been mostly hampered by the high cost, slow response times and cumbersome nature of the equipment. To address these limitations, a novel calorimetric biosensor is proposed by integrating a polymer based micro-reaction chamber on a MEMS thin film freestanding microthermopile sensor. The thermopile will be fabricated on a freestanding micromechanical structure such as a cantilever with the cold junctions placed on the bulk of the silicon chip (the rim) and the hot junctions on the freestanding structure. A polymer-based reaction chamber will be integrated right above the hot junctions of the thermopile. The large thermal mass and good thermal conductivity of the rim keeps the cold junctions at room temperature whereas the unconstrained cantilever tip will rise in temperature due to the heat of reaction. Coating the hot junctions with specific immobilized enzymes will provide selectivity by catalyzing only the reaction of the corresponding analyte. The sensor will also be used for the accurate measurement of the specific heat and thermal diffusivity of the reactants. Real-time monitoring of these thermal properties will provide with an independent tool for analyzing the progress of the biochemical reaction.