A cyanine dye probe for K + detection based on DNA construction of G-quadruplex

Potassium ion (K + ) plays an important role in the maintenance of cellular biological process for human health. Thus, the detection of K + is very important. Here, based on the interaction between thiamonomethinecyanine dye and G-quadruplex formation sequence (PW17), K + detection spectrum was characterized by UV–Vis spectrometry. The single-stranded sequence of PW17 can fold into G-quadruplex in the presence of K + . PW17 can induce a dimer-to-monomer transition of the absorption spectrum of cyanine dyes. This method shows high specificity against some other alkali cations, even at high concentrations of Na + . Further, this detection strategy can realize the detection of K + in tap water. Graphical abstract