Label-free fluorescence detection of mercury(ii) and glutathione based on Hg2+-DNA complexes stimulating aggregation-induced emission of a tetraphenylethene derivative

Abstract

Herein, a sensitive and selective sensor for mercury(II) and glutathione based on the aggregation-induced emission (AIE) of a tetraphenylethene derivative stimulated by Hg(2+)-DNA complexes is reported. Aggregation complexes of AIE probes, quaternized tetraphenylethene salt and anti-Hg(2+) aptamer ssDNA, were formed based on the electrostatic interactions between the ammonium cation of AIE probes and the backbone phosphate anions of DNA. In the presence of target Hg(2+), the aptamer ssDNA with thymine (T)-rich sequences selectively bound with Hg(2+) to form an Hg(2+)-bridged T base pair and the ssDNA changed into a hairpin-like structure. Therefore the AIE probing molecules were brought to be positioned closer. Accordingly, the conformational change of aptamer ssDNA resulted in an obvious enhancement in the fluorescence of the probing complex enabling the sensitive and selective detection of Hg(2+). Furthermore, upon reaction of Hg(2+) with biothiols, the compact structure was destroyed and the fluorescence decreased consequently. Sensitive detection of GSH was realised based on the decrease of fluorescence of the probing complex. The target-aptamer complexes stimulating aggregation-induced emission therefore show great promise for environmental and biological process monitoring and disease diagnosis.

pH-responsive drug delivery system based on AIE luminogen functionalized layered zirconium phosphate nano-platelets

“…All other reagents in this work were used without further purification. Quaternary tetraphenylethene salt (TPEN) was prepared according to the reference [16]. …”

New Chemo-/Biosensors with Silole and Tetraphenylethene Molecules Based on the Aggregation and Deaggregation Mechanism

“…A different sensing approach for Hg 2þ was based on the ensemble of 8 and thymine-rich single-stranded DNA (ssDNA) [14]. Owing to the electrostatic and hydrophobic interactions, fluorescent aggregates were formed for 8 in the presence of ssDNA.…”

Label‐free Fluorescent Sensor for Probing Heparin‐Protein Interaction Based on Supramolecular Assemblies

“…Fluorescence spectroscopy is a very simple and sensitive method that can provide a wealth of information about heparin-protein interactions on very small amounts of sample. [17][18][19][20][21][22] However, this technique is not commonly used as the most frequently reported methods were measured through changes in the environment of intrinsic fluorophores such as tyrosine and tryptophan [17] or labeled fluorescent dyes. [18,19] Supramolecular assemblies from surfactants are of interest because of their container properties in aqueous solutions.…”