Understanding molecular transport in polyelectrolyte brushes (PEBs) is crucial for applications such as separations, drug delivery, anti-fouling, and biosensors, where structural features of the polymer control intermolecular interactions. The complex structure and local heterogeneity of PEBs, while theoretically predicted, are not easily accessed with conventional experimental methods. In this work, we use 3D single-molecule tracking to understand transport behavior within a cationic poly(2-(,-dimethylamino)ethyl acrylate) (PDMAEA) brush using an anionic dye, Alexa Fluor 546, as the probe. The analysis is done by a parallelized, unbiased 3D tracking algorithm. Our results explicitly demonstrate that spatial heterogeneity within the brush manifests as heterogeneity of single-molecule displacements. Two distinct populations of probe motion are identified, with anticorrelated axial and lateral transport confinement, which we believe to correspond to intra- vs inter-chain probe motion.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.langmuir.3c00868 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Vestibular Implant Surgery: How to Deal With Obstructed Semicircular Canals-A Diagnostic and Surgical Guide.
J Otolaryngol Head Neck Surg
January 2025
Division of Otorhinolaryngology-Head and Neck Surgery, Department of Clinical Neurosciences, Geneva University Hospitals, University of Geneva, Geneva, Switzerland.
Background: A vestibular implant can partially restore vestibular function by providing motion information through implanted electrodes. During vestibular implantation, various obstructions of the semicircular canals, such as protein deposits, fibrosis, and ossification, can be encountered. The objective was to explore the relationship between preoperative imaging and intraoperative findings of semicircular canal obstruction and to develop surgical strategies for dealing with obstructions of the semicircular canal(s) in patients eligible for vestibular implantation.
View Article and Find Full Text PDFMetrology with a twist: probing and sensing with vortex light.
Light Sci Appl
January 2025
School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg, 2050, South Africa.
Optical metrology is a well-established subject, dating back to early interferometry techniques utilizing light's linear momentum through fringes. In recent years, significant interest has arisen in using vortex light with orbital angular momentum (OAM), where the phase twists around a singular vortex in space or time. This has expanded metrology's boundaries to encompass highly sensitive chiral interactions between light and matter, three-dimensional motion detection via linear and rotational Doppler effects, and modal approaches surpassing the resolution limit for improved profiling and quantification.
View Article and Find Full Text PDFFrom femtoseconds to minutes: Spectroscopic study of optically induced thermal diffusion in aqueous solution of rhodamine B.
Photochem Photobiol
December 2024
Institute of Chemistry, State University of Campinas, Campinas, São Paulo, Brazil.
Given that non-equilibrium molecular motion in thermal gradients is influenced by both solute and solvent, the application of spectroscopic methods that probe each component in a binary mixture can provide insights into the molecular mechanisms of thermal diffusion for a large class of systems. In the present work, we use an all-optical setup whereby near-infrared excitation of the solvent leads to a steady-state thermal gradient in solution, followed by characterization of the non-equilibrium system with electronic spectroscopy, imaging, and intensity. Using rhodamine B in water as a case study, we perform measurements as a function of solute concentration, temperature, wavelength, time, near-infrared laser power, visible excitation wavelength, and isotope effect.
View Article and Find Full Text PDFHydrogen Bond Blueshifts in Nitrile Vibrational Spectra Are Dictated by Hydrogen Bond Geometry and Dynamics.
JACS Au
December 2024
Freie Universität Berlin, Physics Department, Experimental Molecular Biophysics, Arnimallee 14, 14195 Berlin, Germany.
Vibrational Stark effect (VSE) spectroscopy has become one of the most important experimental approaches to determine the strength of noncovalent, electrostatic interactions in chemistry and biology and to quantify their influence on structure and reactivity. Nitriles (C≡N) have been widely used as VSE probes, but their application has been complicated by an anomalous hydrogen bond (HB) blueshift which is not encompassed within the VSE framework. We present an empirical model describing the anomalous HB blueshift in terms of H-bonding geometry, i.
View Article and Find Full Text PDFCoupling the thermal acoustic modes of a bubble to an optomechanical sensor.
Microsyst Nanoeng
December 2024
ECE Department, University of Alberta, 9211-116 St. NW, Edmonton, T6G 1H9, AB, Canada.
Optomechanical sensors provide a platform for probing acoustic/vibrational properties at the micro-scale. Here, we used cavity optomechanical sensors to interrogate the acoustic environment of adjacent air bubbles in water. We report experimental observations of the volume acoustic modes of these bubbles, including both the fundamental Minnaert breathing mode and a family of higher-order modes extending into the megahertz frequency range.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!