The dynamics of photons in fluorescent molecules plays a key role in fluorescence imaging, optical sensing, organic photovoltaics, and displays. Photobleaching is an irreversible photodegradation process of fluorophores, representing a fundamental limitation in relevant optical applications. Chemical reagents are used to suppress the photobleaching rate but with exceptionally high specificity for each type of fluorophore. Here, using organic hyperbolic materials (OHMs), an optical platform to achieve unprecedented fluorophore photostability without any chemical specificity is demonstrated. A more than 500-fold lengthening of the photobleaching lifetime and a 230-fold increase in the total emitted photon counts are observed simultaneously. These exceptional improvements solely come from the low-loss hyperbolic dispersion of OHM films and the large resultant Purcell effect in the visible spectral range. The demonstrated OHM platform may open up a new paradigm in nanophotonics and organic plasmonics for super-resolution imaging and the engineering of light-matter interactions at the nanoscale.
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http://dx.doi.org/10.1002/adma.202006496 | DOI Listing |
Biomaterials
January 2025
Center for AIE Research, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China; School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong, 518172, China. Electronic address:
Multimodal phototheranostics on the basis of single molecular species shows inexhaustible and vigorous vitality, particularly those emit fluorescence in the second near-infrared window (NIR-II), the construction of such exceptional molecules nonetheless retains formidably challenging. In view of the undiversified molecular skeletons and insufficient phototheranostic outputs of previously reported NIR-II fluorophores, herein, electron acceptor engineering based on heteroatom-inserted rigid-planar pyrazinoquinoxaline was manipulated to fabricate aggregation-induced emission (AIE)-featured NIR-II counterparts with donor-acceptor-donor (D-A-D) architecture. Systematical investigations substantiated that one of those synthesized AIE molecules, namely 4TPQ, incorporating a fused thiophene acceptor, synchronously exhibited high molar absorptivity (ε), NIR-II emission, typical AIE tendency, significant reactive oxygen species (ROS) generation, and high photothermal conversion efficiency.
View Article and Find Full Text PDFCurr Opin Chem Biol
January 2025
Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066, Madhya Pradesh, India; Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, 462066, Madhya Pradesh, India. Electronic address:
Animal venom contains ion channel-targeting peptide toxins that inflict paralysis or pain. The high specificity and potency of these toxins for their target ion channels provides enticing opportunities for their deployment as tools in channel biology. Mechanistic studies on toxin-mediated ion channel modulation have yielded landmark breakthroughs in our understanding of channel architectures and gating mechanisms.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, KU Leuven, Leuven 3001, Belgium.
The ability to address specific sequences within DNA is of tremendous interest in biotechnology and biomedicine. Various technologies have been established over the past few decades, such as nicking enzymes and methyltransferase-directed sequence-specific labeling, transcription activator-like effector nucleases (TALENs), the CRISPR-Cas9 system, and polyamides of heterocycles as sequence-specific DNA minor groove binders. Pyrrole-imidazole polyamides have been reported to recognize predetermined DNA sequences, and some successful attempts have demonstrated their potential in regulating gene expression.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37212, United States.
Atomically thin 2D materials present the potential for advancing membrane separations via a combination of high selectivity (from molecular sieving) and high permeance (due to atomic thinness). However, the creation of a high density of precise nanopores (narrow-size-distribution) over large areas in 2D materials remains challenging, and nonselective leakage from nanopore heterogeneity adversely impacts performance. Here, we demonstrate protein-enabled size-selective defect sealing (PDS) for atomically thin graphene membranes over centimeter scale areas by leveraging the size and reactivity of permeating proteins to preferentially seal larger nanopores (≥4 nm) while preserving a significant amount of smaller nanopores (via steric hindrance).
View Article and Find Full Text PDFTalanta
April 2025
Department of Chemistry, Capital Normal University, Xisanhuan North Road. 105, Beijing, 100048, China. Electronic address:
Methods for evaluation of immobilized-small molecule-binding aptamers are rare. In this study, taking the evaluation of 17β-Estradiol (E2) aptamers as an example, we first summarized the reported affinity and specificity results of 16 E2 aptamers, highlighting the issues of insufficient and inconsistent results and the lacking of evaluation of immobilized aptamers. We further exemplified the limited application scope of current affinity techniques by testing the two most widely-applied E2 aptamers, Kim76 and Alsa35, using the three label-free fluorescence assays and two nuclease protection assays.
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