Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany.
ACS Nano. 2011 Sep 27;5(9):7436-42. doi: 10.1021/nn202351j. Epub 2011 Aug 29.
Detection and analysis of magnetic nanoobjects is a crucial task in modern diagnostic and therapeutic techniques applied to medicine and biology. Accomplishment of this task calls for the development and implementation of electronic elements directly in fluidic channels, which still remains an open and nontrivial issue. Here, we present a novel concept based on rolled-up nanotechnology for fabrication of multifunctional devices, which can be straightforwardly integrated into existing fluidic architectures. We apply strain engineering to roll-up a functional nanomembrane consisting of a magnetic sensor element based on Py/Cu multilayers, revealing giant magnetoresistance (GMR). The comparison of the sensor's characteristics before and after the roll-up process is found to be similar, allowing for a reliable and predictable method to fabricate high-quality ultracompact GMR devices. The performance of the rolled-up magnetic sensor was optimized to achieve high sensitivity to weak magnetic fields. We demonstrate that the rolled-up tube itself can be efficiently used as a fluidic channel, while the integrated magnetic sensor provides an important functionality to detect and respond to a magnetic field. The performance of the rolled-up magnetic sensor for the in-flow detection of ferromagnetic CrO(2) nanoparticles embedded in a biocompatible polymeric hydrogel shell is highlighted.
磁性纳米物体的检测和分析是应用于医学和生物学的现代诊断和治疗技术中的关键任务。完成这项任务需要开发和实施直接在流道中的电子元件，这仍然是一个开放且具有挑战性的问题。在这里，我们提出了一种基于卷绕纳米技术的新概念，用于制造多功能器件，可以直接集成到现有的流道结构中。我们应用应变工程来卷绕一个功能纳米膜，该纳米膜由基于Py/Cu多层的磁传感器元件组成，显示出巨大的磁电阻(GMR)。我们发现，在卷绕过程前后对传感器特性进行比较是相似的，这允许使用可靠且可预测的方法来制造高质量的超紧凑型 GMR 器件。优化了卷绕磁传感器的性能以实现对弱磁场的高灵敏度。我们证明，卷绕管本身可以有效地用作流道，而集成的磁传感器提供了检测和响应磁场的重要功能。强调了卷绕磁传感器在嵌入生物相容性聚合物水凝胶壳中的铁磁 CrO(2)纳米颗粒的流动检测中的性能。
