Polymer microspheres can be fluorescently-coded for multiplexing molecular analysis, but their usage has been limited by fluorescent quenching and bleaching and crowded spectral domain with issues of cross-talks and background interference. Each bioassay step of mixing and separation of analytes and reagents require off-line particle handling procedures. Here, we report that stray magnetic fields can code and decode a collection of hierarchically-assembled beads. By the microfluidic assembling of mesoscopic superparamagnetic cores, diverse and non-volatile stray magnetic field response can be built in the series of microscopic spheres, dumbbells, pears, chains and triangles. Remarkably, the set of stray magnetic field fingerprints are readily discerned by a compact giant magnetoresistance sensor for parallelised screening of multiple distinctive pathogenic DNAs. This opens up the magneto-multiplexing opportunity and could enable streamlined assays to incorporate magneto-mixing, washing, enrichment and separation of analytes. This strategy therefore suggests a potential point-of-care testing solution for efficient kinetic assays.

中文翻译：

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用于多重动力学生物测定平台的杂散磁场的编码和解码

可以对聚合物微球进行荧光编码以进行多重分子分析，但是由于荧光猝灭和漂白以及拥挤的光谱域（具有串扰和背景干扰），聚合物微球的使用受到了限制。混合和分离分析物和试剂的每个生物测定步骤都需要离线颗粒处理程序。在这里，我们报告说杂散磁场可以编码和解码一组分层组装的磁珠。通过介观超顺磁性核的微流体组装，可以在一系列微观球体，哑铃，梨，链和三角形中建立各种非挥发性的杂散磁场响应。值得注意的是 紧凑的巨型磁阻传感器可轻松识别出一组杂散磁场指纹，用于并行筛选多种独特的致病性DNA。这打开了磁多路复用的机会，并使简化的分析方法能够结合磁混合，洗涤，富集和分离分析物。因此，该策略为有效的动力学分析提供了潜在的即时检验解决方案。