A target-induced three-way G-quadruplex junction for 17β-estradiol monitoring with a naked-eye readout†
Abstract
A label-free and enzyme-free three-way G-quadruplex junction sensing system for the amplified detection of 17β-estradiol has been constructed by the ingenious coupling of split G-quadruplex DNAzyme with toehold-mediated strand displacement. The biosensor is ultrasensitive, enabling the visual detection of 17β-estradiol concentrations as low as 1 fM without instrumentation.