NANOSCALE: Miniaturized On-chip Biosensors by In Situ Assembly of Colloidal Particles

微型传感器将通过将胶体组件与芯片上的微图案电极连接而产生。微观的，电子可读的生物传感器将由乳胶颗粒原位组装。传感器的活动区域将由悬浮粒子产生，悬浮粒子在电介质作用下收集在电极之间微米大小的间隙中，并通过修改操作的胶体相互作用来组装。将粒子固定到传感器贴片中的关键步骤是将排斥相互作用降低到一定程度，使范德华力和疏水力使粒子凝固。微观传感器检测的理论极限接近几百个分子的极低极限。其中一个目标是研究改进先前制造的设备的方法。通过在传感器区域上产生电渗透通量和优化间隙几何形状，可以提高速度和灵敏度。利用微冲压技术在电极间隙中直接固定蛋白质的传感器也将得到发展。如果成功，这项工作将导致一种改进的传感器，用于快速、灵敏的免疫测试。

Miniaturized sensors will be created by interfacing of colloidal assemblies with on-chip micropatterned electrodes. The microscopic, electronically readable biosensors will be assembled in situ from latex particles. The active areas of the sensors will be generated from suspended particles collected in micrometer-sized gaps between the electrodes under the action of dielectophoesis and assembled by modification of the operating colloidal interactions. The key step in particle immobilization into sensor patches will be to decrease the repulsive interactions to a degree where the van der Waals and hydrophobic forces coagulate the particles. The theoretical limit of detection of the microscopic sensors approaches an extremely low limit of a few hundred molecules. One goal will be to study methods for improvements of devices previously fabricated. Speed and sensitivity will be increased by generating an electro-osmotic flux over the sensor area and by optimizing the gap geometry. Sensors based on direct protein immobilization in the gap between the electrodes fabricated by microstamping will also be developed. If successful, this work will lead to an improved sensor for rapid, sensitive immunological testing.