E-DNA sensors are rapid, selective and readily reusable.45 (Top) For example, an E-DNA sensor specifically responds to target even in the presence of 50,000× excess genomic DNA and when deployed directly in complex “dirty” samples such as clinical materials, soil-suspensions and foodstuffs. (Bottom) E-DNA sensors equilibrate within minutes and are regenerated via a simple, 30 s wash with deionized water.