Label-free Detection of Zn2+ Based on G-quadruplex

Abstract

Herein, we developed a sensing strategy for the label-free detection of Zn 2+ based on G-quadruplex. In the absence of Zn 2+ , there was a fluorescence enhancement of thioflavin T by interaction with human telomere sequence. On the addition of Zn 2+ , Zn 2+ induced a more compact G-quadruplex structure to release thioflavin T, resulting in a fluorescence decrease. This simple "mix-then-detect" method gave the detection limit of 0.91 μM with linear dynamic ranges from 0 to 10 μM. Because it does not require the use of expensive and unstable DNAzyme systems, or need synthesis and modification of nanomaterials, this label-free biosensor is simple, fast, cost-effective and applicable for real samples taken from lake water.

Stimuli-responsive and self-healing supramolecular Zn(ii)–guanosine metal–organic gel for Schottky barrier diode application

“…ThT is a hydrophilic dye and gives strong fluorescence enhancement upon binding to G-quartet motifs. 65,66,69 It was found that an aqueous alkaline solution of ThT (5 mM) showed negligible fluorescence (Fig. S4a, ESI †).…”

Label-free DNA-based biosensors using structure-selective light-up dyes

“…75 G4s have been widely used as signal transducers in sensing applications by employing G4-binding fluorescent ligands or dyes. 76,77 Our group has devoted continuous efforts towards the development of LFBs using G4-specific dyes for the sensing of ions, 81,82 nucleic acids, 83,84 protein and enzyme activity [85][86][87] etc. As shown in Fig.…”

A Simple and Sensitive Method for Auramine O Detection Based on the Binding Interaction with Bovin Serum Albumin

“…The spectrophotometric method is a well-developed, low cost, versatile and simple analytical technique, which had been widely applied in detecting some metal ions, 22,23 proteins, 24,25 carbon dots 26,27 and organic compounds. 28 Nowadays, there are several studies on AO detection, 6,7,29 but in this work, we have, for the first time, introduced BSA for highly selective and sensitive determination of AO by fluorescence.…”