Activity-regulated cytoskeleton-associated protein (Arc) forms virus-like capsids for mRNA transport between neurons. Unlike HIV-1 Group-specific Antigen (Gag), which uses its Nucleocapsid (NC) domain to bind HIV-1 genomic mRNA, mammalian Arc lacks the NC domain, and their direct mRNA binding interactions remain underexplored. This study examined rat Arc's binding to rat Arc 5' UTR (A5U), HIV-1 5' UTR (H5U), and GFP mRNAs, revealing weak binding with no significant preference.
View Article and Find Full Text PDFExtracellular vesicles (EVs) are emerging as key diagnostic biomarkers due to their widespread presence in body fluids and the proteins on their surfaces, which reflect the identity and condition of their parent cells. Research has focused on detecting EVs with biosensors that target individual transmembrane proteins (TMPs) like tetraspanins. However, due to TMP heterogeneity and the formation of tetraspanin-enriched microdomains (TEMs), cotargeting multiple TMPs is a promising strategy for enhancing EV detection.
View Article and Find Full Text PDFUrogenital tuberculosis is one of common sites of extrapulmonary tuberculosis. A 60-year-old man with an elevated prostate-specific antigen level underwent multiparametric MRI, which revealed abnormal signals in the prostate. However, the 68 Ga-PSMA PET/CT results were unrevealing.
View Article and Find Full Text PDFExtracellular vesicles (EVs) are preeminent carriers of biomarkers and have become the subject of intense biomedical research for medical diagnostics using biosensors. To create effective EV-based immunoassays, it is imperative to develop surface chemistry approaches with optimal EV detection targeting transmembrane protein biomarkers that are not affected by cell-to-cell variability. Here, we developed a series of immunoassays for the detection of EVs derived from mouse monocyte cells using surface plasmon resonance (SPR) biosensors.
View Article and Find Full Text PDFDirect detection of circularly polarized light (CPL) holds great promise for the development of various optical technologies. Chiral 2D organic-inorganic halide perovskites make it possible to fabricate CPL-sensitive photodetectors. However, selectively detecting left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) light remains a significant challenge.
View Article and Find Full Text PDFThe blood-brain barrier (BBB) restricts the systemic delivery of messenger RNAs (mRNAs) into diseased neurons. Although leucocyte-derived extracellular vesicles (EVs) can cross the BBB at inflammatory sites, it is difficult to efficiently load long mRNAs into the EVs and to enhance their neuronal uptake. Here we show that the packaging of mRNA into leucocyte-derived EVs and the endocytosis of the EVs by neurons can be enhanced by engineering leucocytes to produce EVs that incorporate retrovirus-like mRNA-packaging capsids.
View Article and Find Full Text PDFThe polaron is an essential photoexcitation that governs the unique optoelectronic properties of organic-inorganic hybrid halide perovskites, and it has been subject to extensive spectroscopic and theoretical investigation over the past decade. A crucial but underexplored question is how the nature of the photogenerated polarons is impacted by the microscopic perovskite structure and what functional properties this affects. To tackle this question, we chemically tuned the interactions between perovskite quantum dots (QDs) to rationally manipulate the polaron properties.
View Article and Find Full Text PDFThis study aimed to investigate the clinical significance of the detection of mononuclear phagocytes subsets in pulmonary sarcoidosis blood and bronchoalveolar lavage fluid (BALF). For this purpose, a total of 52 patients with pulmonary sarcoidosis were selected as the study group, 52 healthy people served as the "NC Group a" (peripheral blood mononuclear cell control group), 47 patients with chronic cough and no pulmonary sarcoidosis who underwent bronchoscopy were used as "control group b" (alveolar lavage fluid macrophage control group). Fasting peripheral blood and BALF were collected, and flow cytometry was used to detect monocytes and macrophage subpopulations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2020
Poly(hydroxymethylated-3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT-MeOH:PSS) conducting polymers are synthesized and incorporated in inverted structured perovskite solar cells (PVSCs) as hole transport materials. The highest occupied molecular orbital of PEDOT-MeOH is lowered by adding a hydroxymethyl (-MeOH) functional group to ethylenedioxythiophene (EDOT), and thus, the work function of PEDOT-MeOH:PSS is increased. Additionally, hydrogen bonding can be formed among EDOT-MeOH monomers and between EDOT-MeOH monomers and sulfate groups on PSS, which promotes PEDOT-MeOH chain growth and enhances PSS doping.
View Article and Find Full Text PDFEpigenetic modifications of DNA are known to modulate gene activity and expression and are believed to result in genetic diseases, such as cancer. Four modified cytosines were discovered in mammalian genomes: 5-methycytoine (5mC), 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxycytosine (5caC). They are regarded as DNA epigenetic markers and play key roles in the regulation of the dynamic balance between DNA methylation and demethylation.
View Article and Find Full Text PDFSurface-enhanced Raman spectroscopy (SERS), which utilizes nanogaps between noble-metal nanostructures as hot spots to yield ultrasensitive SERS signals, is an outstanding label-free and straightforward tool for DNA methylation analysis. Herein, a plasmonic gold nanohole array (PGNA) with well-controlled hot spots and an open surface was designed as a SERS substrate for DNA methylation detection. A finite-difference time-domain (FDTD) simulation was first employed to investigate the electric field distributions of the PGNA as a function of the geometric parameters.
View Article and Find Full Text PDFThe performance of surface plasmon resonance (SPR)-based bacterial biosensors is often compromised as a result of diffusion-limited mass transport of bacteria to the sensing surface. In this work, dually functional interdigitated electrodes (IDEs) were developed to sustain SPR and increase bacterial mass transport through external application of dielectrophoresis (DEP). IDEs were defined into 50 nm Au films with fixed electrode gaps ( E = 5 μm) and varied electrode widths ( E = 10, 20, and 100 μm), referred to as interdigitated SPR (iSPR) chips.
View Article and Find Full Text PDFNarrowband ultraviolet (UV) photodetectors are highly desired in multiple areas. Photodetectors based on organic-inorganic nanocomposites offer high sensitivity, widely adjustable response range, light weight, and low-temperature solution processibility. However, the broad absorption range of organic and inorganic semiconductor materials makes it difficult to achieve a narrowband detection feature for nanocomposite photodetectors.
View Article and Find Full Text PDFLightweight and flexible ultraviolet (UV) photodetectors (PDs) have wide applications and have attracted more attention. PDs using organic and inorganic nanocomposites as active layers with a photodiode configuration could achieve photomultiplication and narrowband photoresponse via the control of microstructure and thickness of active layers. Here, we fabricated flexible UV PDs on indium tin oxide-coated poly(ethylene terephthalate) substrates with a nanocomposite active layer composed of ZnO nanoparticles blended with a wide band gap conjugated polymer, poly[(9,9-dioctylfluorenyl-2,7-diyl)- alt- co-(bithiophene)] (F8T2).
View Article and Find Full Text PDFOrganic-inorganic hybrid ultraviolet photodetectors with tunable spectral response are desirable for many different applications. In this work, we blended poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) with ZnO nanoparticles in weight ratios of 1 : 1 and 2 : 1 to create charge traps within the active layers for devices with the conventional structure ITO/PEDOT : PSS/PTAA : ZnO/BCP/Al. Thin (150-200 nm) and thick (1400-1900 nm) active layers were employed to utilize charge collection narrowing (CCN).
View Article and Find Full Text PDFAs the prevalence of antibiotic-resistant bacteria continues to rise, biosensing technologies are needed to enable rapid diagnosis of bacterial infections. Furthermore, understanding the unique biochemistry of resistance mechanisms can facilitate the development of next generation therapeutics. Surface-enhanced Raman scattering (SERS) offers a potential solution to real-time diagnostic technologies, as well as a route to fundamental, mechanistic studies.
View Article and Find Full Text PDFCellulose paper is an ideal diagnostic platform for low-cost, easily disposable and lightweight implementation, but requires surface modification to achieve detection with high sensitivity and specificity in complex media. In this work, a polymer-catechol conjugate containing a superhydrophilic nonfouling poly(carboxylbetaine) (pCB) and four surface-binding l-3,4-dihydroxyphenylalanine (DOPA) groups, pCB-(DOPA), were applied onto a paper-based sensor surface via a simple "graft-to" immersion process to render the surface with both nonfouling and protein functionalizable properties. This dip-coating technique is effective, convenient and robust as compared to the "graft-from" techniques reported previously with similar nonfouling properties.
View Article and Find Full Text PDFA multilayered architecture including a thin Au film supporting an X-shaped nanohole array and a thick continuous Au film separated by a Cytop dielectric layer is reported in this work. Long-range surface plasmon resonance (LR-SPR) was generated at the top Au/water interface, which also resulted in a long-range surface-enhanced Raman scattering (LR-SERS) effect. LR-SPR originates from the coupling of surface plasmons (SPs) propagating along the opposite sides of the thin Au film embedded in a symmetric refractive index environment with Cytop (n = 1.
View Article and Find Full Text PDFSurface-enhanced Raman spectroscopy (SERS) has been recognized as one of the most sensitive sensing technologies and has been used for a variety of chemical, biological and medical applications. Compared to traditional direct SERS detection using a bare metal SERS-active substrate, surface chemistries and surface modifications on SERS-active substrates are becoming more and more important to achieve the detection of target analytes with a small surface affinity or weak Raman activity. As one special class of surface chemistries and modifications for SERS-active substrates, the thiophenol-based molecules offer new functions, increased sensitivity, and improved specificity to SERS-based sensing.
View Article and Find Full Text PDFIndium tin oxide (ITO) is the most common transparent electrode used in organic photovoltaics (OPVs), yet limited indium reserves and poor mechanical properties make it non-ideal for large-scale OPV production. To replace ITO, we designed, fabricated, and deployed plasmonic nanostructured electrodes in inverted OPV devices. We found that active layer absorption is significantly impacted by ZnO thickness which affects the optical field distribution inside the resonant cavity formed between the plasmonic nanostructured electrode and top electrode.
View Article and Find Full Text PDFSurface-enhanced Raman spectroscopy (SERS) is an ultrasensitive analytical technique with molecular specificity, making it an ideal candidate for therapeutic drug monitoring (TDM). However, in critical diagnostic media including blood, nonspecific protein adsorption coupled with weak surface affinities and small Raman activities of many analytes hinder the TDM application of SERS. Here we report a hierarchical surface modification strategy, first by coating a gold surface with a self-assembled monolayer (SAM) designed to attract or probe for analytes and then by grafting a non-fouling zwitterionic polymer brush layer to effectively repel protein fouling.
View Article and Find Full Text PDFUnlabelled: For surface-based diagnostic devices to achieve reliable biomarker detection in complex media such as blood, preventing nonspecific protein adsorption and incorporating high loading of biorecognition elements are paramount. In this work, a novel method to produce nonfouling zwitterionic hydrogel coatings was developed to achieve these goals. Poly(carboxybetaine acrylamide) (pCBAA) hydrogel thin films (CBHTFs) prepared with a carboxybetaine diacrylamide crosslinker (CBAAX) were coated on gold and silicon dioxide surfaces via a simple spin coating process.
View Article and Find Full Text PDFBinary lead and tin perovskites offer the benefits of narrower band gaps for broader adsorption of solar spectrum and better charge transport for higher photocurrent density. Here, we report the growth of large, smooth crystalline grains of bianry lead and tin triiodide perovskite films via a two-step solution process with thermal plus solvent vapor-assisted thermal annealing. The crystalline SnxPb1-xI2 films formed in the first step served as the templates for the formation of crystalline CH3NH3SnxPb1-xI3 films during the second step interdiffusion of methylammonium iodide (MAI).
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2016
Unlabelled: Inverted CdSe quantum dots (QDs):poly (3-hexylthiophene) (P3HT) organic/inorganic hybrid solar cells (OIHSCs) with the
Pedot: PSS/MoO3 dual hole transport layers (HTLs) showed superior performance over those with a single HTL of
Pedot: PSS or MoO3. The enhanced electron blocking at the active layer/anode interface as well as the prevention of leakage current accounted for the enhancement in the efficiency of the solar cells with the dual HTLs. By adopting the inverted structure and using the dual HTLs, the resistive losses of the CdSe QDs:P3HT hybrid system at high illumination power were effectively prevented.
The extracellular pH (pHe) of living cells is one of the major factors that influence cell behaviors including cycle progression, migration, and proliferation, as well as metastasis and invasion of tumor cells. Thus, accurate sensing and mapping of the pHe is still a critical yet challenging task in the study of pHe-dependent cell behaviors. In this work, we present a method to map pHe of living cells based on surface-enhanced Raman spectroscopy (SERS).
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