Conjugated Polymer/Graphene Oxide Complexes for Photothermal Activation of DNA Unzipping and Binding to Protein

Abstract

DNA−protein interactions control DNA transcription, recombination, restriction, and replication, which play an important role in regulating life activities. We developed a new strategy to photothermally regulate DNA unzipping and binding to single-stranded binding protein (SSBP) based on the hybrid systems of graphene oxide (GO) and conjugated polymer. GO is applied as the photothermal modulator to activate the unzipping of dsDNA into ssDNA. Upon near-infrared (NIR) laser irradiation, the thermal melting transition of DNA is promoted, which results in much farther distance between poly[(9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-fluorenylene phenylene dibromide] (PFP) and fluorescein labeled at the terminus of the DNA in comparison to that of dsDNA before NIR irradiation in the presence of GO. Therefore, the fluorescence resonance energy transfer (FRET) efficiency for PFP/fluorescein becomes weaker upon irradiation. Moreover, FRET efficiency could readily recover when the unzipped DNA hybridizes with SSBP. In this strategy, PFP/GO serves as detector and activator for the DNA unzipping and interacting with proteins, providing a facile and effective method for the regulation and detection of DNA−protein interactions.

Aggregation-Induced Emission: A Trailblazing Journey to the Field of Biomedicine

“…At present, numerous fluorescent bioprobes have been designed and developed for FL imaging, most of which have already elicited remarkable impacts on the research paradigm of biological studies. These fluorescent materials include but are not limited to organic dyes, − fluorescent conjugated polymers, − quantum dots, , rare-earth ion-based nanoparticles (e.g., lanthanide-doped up-conversion nanoparticles), − metal nanoclusters, − carbon nanomaterials (e.g., carbon nanotubes , and carbon nanodots), , and various fluorescent proteins. , Among them, organic materials possess a series of outstanding properties, such as good biocompatibility, tunable spectral characteristics, facile processability, and versatile modification strategies, rendering them fantastic candidates for FL imaging.…”

Synergistic Photodynamic and Photothermal Antibacterial Therapy Based on a Conjugated Polymer Nanoparticle-Doped Hydrogel

“…As the topical antibacterial methods, photodynamic therapy (PDT) and photothermal therapy (PTT) are two commonly used antibacterial therapies, which are widely concerned because of their excellent bactericidal ability and light controllability. − Both antibacterial methods control the antibacterial effect by easily tuning the illumination time and light intensity. As the core of phototransformation, photosensitizer and photothermal agents have a great influence on the effects of PDT and PTT, respectively. , In recent years, conjugated polymers have been extensively used in chemical or biological information sensing, cell imaging, disease diagnosis, and treatment due to their outstanding light capture performance and signal amplification. − Many studies have shown that conjugated polymers can sensitize surrounding oxygen molecules under white light and produce reactive oxygen species (ROS) . Meanwhile, certain conjugated polymers with near-infrared absorption can convert light energy into thermal energy under near-infrared (NIR) light .…”

Oligo (p-Phenylene Vinylene)/Polyisocyanopeptide Biomimetic Composite Hydrogel-Based Three-Dimensional Cell Culture System for Anticancer and Antibacterial Therapeutics

“…Effective BRET requires the emission spectrum of the donor and the excitation spectrum of the acceptor overlaps. Here, we choose luminol as the donor and OPV as the receptor for that the absorption spectra of OPV in aqueous solution ranges from 350 to 550 nm and the bioluminescence of luminol exhibits a maximum emission peak at 425 nm under alkaline conditions in the presence of hydrogen peroxide and horseradish peroxidase (HRP), which meets the condition of the bioluminescence resonance energy transfer (BRET) as the donor–acceptor pair owing to the overlap of absorption spectra of OPV and luminescence spectra of luminol. OPV is a cationic oligo ( p -phenylene vinylene) with unique light-harvesting like traditional conjugated polymers − and optical signal amplification capabilities. − Under alkaline conditions, luminol is oxidized in the presence of hydrogen peroxide and HRP to form a negatively charged luminescent intermediate .…”