Aligning fast alternating current electroosmotic flow fields and characteristic frequencies with dielectrophoretic traps to achieve rapid bacteria detection
Aligning fast alternating current electroosmotic flow fields and characteristic frequencies with dielectrophoretic traps to achieve rapid bacteria detection
复制标题
DOI：
10.1002/elps.200500129
复制
发表时间：
2005-10-01
期刊：
影响因子：
2.9
通讯作者：
Chang, HC
中科院分区：
文献类型：
--
作者：
Gagnon, Z;Chang, HC
定制设计的交流电渗（AC-EO）停滞流被用来对流生物颗粒全球从散装溶液局部介电泳（DEP）的陷阱，在流动停滞点对齐。多尺度陷阱，与一个典型的捕获时间为秒的稀释70 μ L体积的10（3）粒子每毫升样品，是几个数量级快于传统的DEP陷阱和早期的AC-EO陷阱与平行，城堡状，或指状电极。一种新型的蛇形线能够维持高电压，高达2500 V-RMS，而不会引起过度的散热或法拉第反应，在强电解质中制造产生强AC-EO流与两个分离的停滞线，一个对齐的字段最小和一个字段最大。连续导线设计允许大的施加电压而不诱导法拉第电极反应。粒子在几秒钟内被捕获在一个陷阱，这取决于它们是否遭受负或正DEP。粒子也可以通过改变所施加的AC场的频率低于粒子不同的交叉频率来从它们各自的陷阱中快速释放。向缓冲器中添加Zwitzerland允许AC-EO和DEP运动的进一步几何和频率对准。因此，相同的装置允许对具有真实电导率、体积和细菌计数的样品进行快速捕获、检测、分选和表征。
Tailor-designed alternating current electroosmotic (AC-EO) stagnation flows are used to convect bioparticles globally from a bulk solution to localized dielectrophoretic (DEP) traps that are aligned at the flow stagnation points. The multiscale trap, with a typical trapping time of seconds for a dilute 70 mu L volume of 10(3) particles per cc sample, is several orders of magnitude faster than conventional DEP traps and earlier AC-EO traps with parallel, castellated, or finger electrodes. A novel serpentine wire capable of sustaining a high voltage, up to 2500 V-RMS, without causing excessive heat dissipation or Faradaic reaction in strong electrolytes is fabricated to produce the strong AC-EO flow with two separated stagnation lines, one aligned with the field minimum and one with the field maximum. The continuous wire design allows a large applied voltage without inducing Faradaic electrode reactions. Particles are trapped within seconds at one of the traps depending on whether they suffer negative or positive DEP The particles can also be rapidly released from their respective traps by varying the frequency of the applied AC field below particle-distinct cross-over frequencies. Zwitterion addition to the buffer allows further geometric and frequency alignments of the AC-EO and DEP motions. The same device hence allows fast trapping, detection, sorting, and characterization on a sample with realistic conductivity, volume, and bacteria count.