A Simple, Sensitive Colorimetric Assay for Coralyne Based on Target Induced Split G-quadruplex Formation

Abstract

The screening of potential drugs specifically binding to polydeoxyadenosine (poly(dA)) has been of great interest in recent studies. We have developed a simple colorimetric strategy through the mechanism of target induced split G-quadruplex formation for detecting coralyne, a poly(dA)-binding drug with noticeable antitumor activity. Two DNA oligonucleotides containing a split G-quadruplex sequence and an adenine-rich sequence are used in our strategy. In the presence of coralyne, the adenine-rich sequences of two oligonucleotides are drawn into close proximity, resulting in the formation of a split G-quadruplex DNAzyme that catalyzes the generation of a colored product. The DNAzyme-based colorimetric assay for coralyne has a linear range of from 0.033 to 1.667 μM with a low detection limit of 16 nM. The developed method is simple, cost-effective and visible; it holds great potential for applications in drug screening.