Chemiluminescent gels of G-quadruplexes in deep eutectic solvents

Abstract

Stabilized G-quadruplex systems have focused on biosensors, chromogenic reaction and chemiluminescence (CL) catalysts. On the present, the main studies are building stable G-quadruplexes to form ionogels and improving the performance of circularly polarized luminescence (CPL) or fluorescence resonance energy transfer (FRET). Here, the uncommon G-quadruplexes promoted by deep eutectic solvents (DESs) were established and used for chemiluminescence resonance energy transfer (CRET) platform. The DES containing choline chloride and urea not only provided solvent environment for guanosine but also facilitated the formulation of the aggregates. The ion-dipole interaction among the cation of choline chloride and guanosine gave rise to the G-quartets and the hydrogen bond networks in DES or π-π interaction maintained the stacking G-quartets being G-quadruplexes. Being bound to the hemin endowed G-quadruplexes peroxidase-like properties, which catalyzed the oxidation of luminol and generated expected chemiluminescence. Subsequently, attaching the luminol and fluorescent dyes to the peroxidase-like G-quadruplex/hemin complexes guaranteed the proximity requirements of CRET donor and acceptor. The CRET eutectogels could flash evident blue, chartreuse or cerise light once they were immersed into H2O2 solution, which endowed the eutectogels ability in grouping displaying objects. This work demonstrated the feasibility of simultaneously fixing the donor and acceptor of energy transfer on G-quadruplexes to develop the CRET platform, taking the luminol and dyes as example. And the instant luminescence property expanded the application of eutectogels in pattern visualization field.