Besant Justin D, Das Jagotamoy, Burgess Ian B, Liu Wenhan, Sargent Edward H, Kelley Shana O
Institute for Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada M5S 3G9.
Department of Pharmaceutical Science, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada M5S 3M2.
Nat Commun. 2015 Apr 22;6:6978. doi: 10.1038/ncomms7978.
Diagnosis of disease outside of sophisticated laboratories urgently requires low-cost, user-friendly devices. Disposable, instrument-free testing devices are used for home and physician office testing, but are limited in applicability to a small class of highly abundant analytes. Direct, unambiguous visual read-out is an ideal way to deliver a result on a disposable device; however, existing strategies that deliver appropriate sensitivity produce only subtle colour changes. Here we report a new approach, which we term electrocatalytic fluid displacement, where a molecular binding event is transduced into an electrochemical current, which drives the electrodeposition of a metal catalyst. The catalyst promotes bubble formation that displaces a fluid to reveal a high contrast change. We couple the read-out system to a nanostructured microelectrode and demonstrate direct visual detection of 100 fM DNA in 10 min. This represents the lowest limit of detection of nucleic acids reported using high contrast visual read-out.
在缺乏先进实验室的情况下进行疾病诊断迫切需要低成本、用户友好型设备。一次性、无需仪器的检测设备用于家庭和医生办公室检测，但仅适用于一小类高丰度分析物。直接、明确的视觉读数是在一次性设备上给出结果的理想方式；然而，现有的能提供适当灵敏度的策略只会产生细微的颜色变化。在此，我们报告一种新方法，我们称之为电催化流体置换，其中分子结合事件被转化为电化学电流，该电流驱动金属催化剂的电沉积。催化剂促进气泡形成，从而置换流体以显示高对比度变化。我们将读数系统与纳米结构微电极相结合，并展示了在10分钟内直接视觉检测100 fM DNA。这代表了使用高对比度视觉读数报告的核酸最低检测限。
