Advancement in the understanding of biomolecular interactions has benefited greatly from development surface-sensitive bioanalytical sensors. To further increase their broad impact, significant efforts are presently being made to enable label-free and specific biomolecule detection with high sensitivity, allowing for quantitative interpretation general applicability at low cost. In this work, we have addressed challenge by developing a waveguide chip consisting flat silica core embedded...

Significance Neurodegenerative diseases are increasing among the world's population, but there no cures. These disorders all involve proteins that assemble into amyloid fibers which results in brain cell death. Evidence suggests association of these with lipid membranes is crucial for both functional and pathological roles. In Parkinson's disease, involved protein, α-synuclein, thought to function trafficking vesicles brain. search mechanistic origins, focus put on identifying neurotoxic...

Advances in lipid nanoparticle (LNP) design have contributed notably to the emergence of current clinically approved mRNA-based vaccines and are high relevance for delivering mRNA combat diseases where therapeutic alternatives sparse. LNP-assisted delivery utilizes ionizable lipid-mediated cargo translocation across endosomal membrane driven by acidification environment. However, this process occurs at a low efficiency, few percent best. Utilizing surface-sensitive fluorescence microscopy...

We describe a new evanescent-wave fluorescence excitation method, ideally suited for imaging of biological samples. The light propagates in planar optical waveguide, consisting thin waveguide core sandwiched between sample an aqueous solution and polymer with matching refractive index, forming symmetric cladding environment. This configuration offers clear advantages over other waveguide-excitation methods, such as superior image quality, wide tunability the evanescent field penetration...

Abstract Fabrication of continuous ultra-thin gold films (<10 nm) on the surface optical polymers (CYCLOTENE and ORMOCLEAR) is reported. Using a range electrical, structural characterization techniques, we show that can be superior to more conventional (inorganic) materials as substrates for realizing films. these transparent polymer substrates, smooth, patternable fabricated with deposition techniques at room temperature, without adhesion or seeding layers, facilitating new photonic...

The most efficient lipid nanoparticles (LNPs) for gene therapeutics rely on specific lipids that protect the oligonucleotide cargo and aid cellular uptake subsequent endosomal escape. Yet, efficacy of current state-of-the-art LNP formulations remains low, a few percent at best. A deeper understanding how cargo, composition, stoichiometry, size, structure, pH-induced conformational changes influence their efficiency is therefore necessary improved design. Given variability these properties,...

We present detailed characterization of a unique high-index-contrast integrated optical polymer waveguide platform where the index cladding material is closely matched to that water. Single-mode waveguides designed operate across large part visible spectrum have been fabricated and properties, including mode size, bend loss evanescent coupling modeled using effective-index approximation, finite-element finite-difference time domain methods. Integrated components such as directional couplers...

The detection of oligonucleotides is a central step in many biomedical investigations. most commonly used methods for detecting often require concentration and amplification before detection. Therefore, developing with direct read-out would be beneficial. Although the amplified oligonucleotides, fluorescent molecular beacons have been proposed such However, reported limits using are relatively high, ranging from 100 nM to few µM, primarily limited by beacon fluorescence background. In this...

Imaging of live cells was carried out using evanescent-wave excitation on a polymer waveguide chip. Integrated waveguide-based interferometric light modulators were fabricated in order to demonstrate on-chip control light, e.g., for time-lapse fluorescence microscopy. When combined with sensitive high-resolution imaging system, the integrated waveguide-excitation platform provides an ideal method near-surface studies cells, where photobleaching and/or phototoxicity effects are critical concern.

We describe how the amorphous fluoropolymer CYTOP can be advantageously used as a waveguide cladding material in integrated optical circuits suitable for applications biophotonics. The unique refractive index of (n = 1.34) enables to well index-matched an optically probed sample solution. Furthermore, ultra-high contrast waveguides fabricated, using conventional polymers core materials, offering route large-scale integration functions on single chip. discuss this platform evanescent-wave...

Resonant photon tunneling was investigated experimentally in multilayer structures containing a high-contrast (TiO(2)/SiO(2)) Bragg mirror capped with semitransparent gold film. Transmission via fundamental cavity resonance compared transmission the Tamm plasmon polariton that appears at interface between metal film and one-dimensional photonic bandgap structure. The Tamm-plasmon-mediated exhibits smaller dependence on angle polarization of incident light for similar values peak...

Extracellular vesicles (EVs) are generating a growing interest because of the key roles they play in various biological processes and their potential use as biomarkers clinical diagnostics efficient carriers drug-delivery gene-therapy applications. Their full exploitation, however, depends critically on possibility to classify them into different subpopulations, task that turn relies means identify unique biomolecular physical signatures. Because large heterogeneity EV samples, such...

Supported lipid bilayers (SLBs) represent one of the most popular mimics cell membrane. Herein, we have used total internal reflection fluorescence microscopy for in-depth characterization vesicle-mediated SLB formation mechanism on a common silica-rich substrate, borosilicate glass. Fluorescently labeling subset vesicles allowed us to monitor adsorption individual labeled vesicles, resolve onset from small seeds patches, and track their growth via SLB-edge-induced autocatalytic rupture...

Emerging biomedical applications such as molecular imaging and drug delivery often require directed binding of nanoparticles to cell-membrane receptors. The specific apparent affinity ligand-functionalized particles is size-dependent, an observation so far solely attributed multivalent receptor–ligand interaction. We question the universality this explanation by demonstrating that kinetics also depends on weak, attractive colloidal-type interaction between a lipid membrane. Applying...

Over the last two decades, supported lipid bilayers (SLBs) have been extensively used as model systems to study cell membrane structure and function. While SLBs traditionally produced from simple mixtures, there has a recent surge in compositional complexity better mimic cellular membranes thereby bridge gap between classic biophysical approaches experiments. To this end, native derived (nSLBs) emerged new category of SLBs. As type biomimetic material, an analytical workflow must be designed...

<title>Abstract</title> Deciphering the extracellular vesicle (EV) heterogeneity is essential for understanding their biological functions and enhancing utility in drug development medical diagnostics. Here, we demonstrate efficacy of label-free surface-based waveguide scattering microscopy, coupled with multiplexed fluorescence readout, quantifying size, inner cargo concentration, surface protein markers at individual EV level. By modulating optical contrast between EVs surrounding medium...

The electronic structure of ZnPc, from sub-monolayers to thick films, on bare and iodated Pt(111) is studied by means X-ray photoelectron spectroscopy, absorption scanning tunneling microscopy. Our results suggest that at low coverage ZnPc lies almost parallel the substrate, in a non-planar configuration induced Zn-Pt attraction, leading an inhomogeneous charge distribution within molecule transfer molecule. does not form complete monolayer Pt surface, due surface-mediated intermolecular...

Assumption-free mass quantification of nanofilms, nanoparticles, and (supra)molecular adsorbates in a liquid environment remains key challenge many branches science. Mechanical resonators can uniquely determine the essentially any adsorbate; yet, when operating environment, dynamically coupled to adsorbate contributes significantly measured response, which complicates data interpretation impairs quantitative determination. Employing Navier–Stokes equation for velocity contact with an...

Nanoparticle interactions with cellular membranes are controlled by molecular recognition reactions and regulate a multitude of biological processes, including virus infections, nanoparticle-mediated communication, drug delivery applications. Aided the design various supported cell membrane mimics, multiple methods have been employed to investigate these types interactions, revealing information on nanoparticle coverage, interaction kinetics, as well binding strength; however, precise...

Determining the surface concentration and diffusivity of cell-membrane-bound molecules is central to understanding numerous important biochemical processes taking place at cell membranes. Here we use high aspect ratio lightguiding properties semiconductor nanowires (NWs) detect presence single freely diffusing proteins bound a lipid bilayer covering NW surface. Simultaneous observation light-emission dynamics hundreds individual NWs occurring on time scale only few seconds interpreted using...

In-depth understanding of the intricate interactions between biomolecules and nanoparticles is hampered by a lack analytical methods providing quantitative information about binding kinetics. Herein, we demonstrate how label-free evanescent light-scattering microscopy can be used to temporally resolve specific protein individual surface-bound (∼100 nm) lipid vesicles. A theoretical model proposed that translates protein-induced changes in intensity into bound mass. Since analysis centered on...

Fluorescence-based detection assays play an essential role in the life sciences and medicine. To offer better sensitivity lower limits of (LOD), there is a growing need for novel platforms with improved readout capacity. In this context, substrates containing semiconductor nanowires may significant advantages, due to their proven light-emission enhancing, waveguiding properties, increased surface area. demonstrate evaluate potential such context diagnostic assays, we have work adopted...

The function of integral membrane proteins is critically dependent on their naturally surrounding lipid membrane. Detergent-solubilized and purified are therefore often reconstituted into cell-membrane mimics analyzed for with single-molecule microscopy. Expansion this approach toward a broad range pharmaceutically interesting drug targets biomarkers however remains hampered by the fact that these have low expression levels, detergent solubilization reconstitution cause protein...