Achieving sensors that can sensitively and selectively quantify levels of analytes in complex biofluids such as blood remains a significant challenge. To address this, we synthesized an array of isolated carbon nanochannels on a flat gold electrode that function as molecular sieves to prevent protein fouling and eliminate the need for antifouling layers. Utilizing a two-step pulsed technique, a reductive pulse expels negative interferences and fouling molecules followed by an oxidative pulse that oxidizes glucose at the bottom of the channel and on the gold surface.
View Article and Find Full Text PDFBackground: Spontaneous bacterial peritonitis (SBP) is one of the most important complications of patients with liver cirrhosis entailing high morbidity and mortality. Making an accurate early diagnosis of this infection is key in the outcome of these patients. The current definition of SBP is based on studies performed more than 40 years ago using a manual technique to count the number of polymorphs in ascitic fluid (AF).
View Article and Find Full Text PDFWith freshwater resources becoming increasingly scarce, the photocatalytic seawater splitting for hydrogen production has garnered widespread attention. In this study, a novel photocatalyst consisting of a Cu core coated is introduced with N-doped C and decorated with single Co atoms (Co-NC@Cu) for solar to hydrogen production from seawater. This catalyst, without using noble metals or sacrificial agents, demonstrates superior hydrogen production effficiency of 9080 µmolgh, i.
View Article and Find Full Text PDFIridium dioxide (IrO), ruthenium dioxide (RuO), and their solid solutions (IrRuO) are very active electrocatalysts for the oxygen evolution reaction (OER). Efficient and facile synthesis of nanosized crystallites of these materials is of high significance for electrocatalytic applications for converting green energy to fuels (power-to-X). Here, we use X-ray scattering to examine reaction conditions for different Ir and Ru precursors resulting in the development of a simple hydrothermal synthesis route using IrCl and KRuO to obtain homogeneous phase-pure IrRuO nanocrystals.
View Article and Find Full Text PDFNanopore sensing is a popular biosensing strategy that is being explored for the quantitative analysis of biomarkers. With low concentrations of analytes, nanopore sensors face challenges related to slow response times and selectivity. Here, we demonstrate an approach to rapidly detect species at ultralow concentrations using an optical nanopore blockade sensor for quantitative detection of the protein vascular endothelial growth factor (VEGF).
View Article and Find Full Text PDFSuperparamagnetic iron core iron oxide shell nanocubes have previously shown superior performance in magnetic resonance imaging T2 contrast enhancement compared with spherical nanoparticles. Iron core iron oxide shell nanocubes were synthesized, stabilized with dimercaptosuccinic acid (DMSA-NC) and physicochemically characterized. MRI contrast enhancement and biocompatibility were assessed .
View Article and Find Full Text PDFThe emergence of ferroelectricity in two-dimensional (2D) metal oxides is a topic of significant technological interest; however, many 2D metal oxides lack intrinsic ferroelectric properties. Therefore, introducing asymmetry provides access to a broader range of 2D materials within the ferroelectric family. Here, the generation of asymmetry in 2D SnO by doping the material with HfZrO (HZO) is demonstrated.
View Article and Find Full Text PDFHerein the development of cellular impedance biosensors, electrochemical impedance spectroscopy, and the general principles and terms associated with the cell-electrode interface is reviewed. This family of techniques provides quantitative and sensitive information into cell responses to stimuli in real-time with high temporal resolution. The applications of cell-based impedance biosensors as a readout in cell biology is illustrated with a diverse range of examples.
View Article and Find Full Text PDFThe recent breakthrough in confining five or more atomic species in nanocatalysts, referred to as high-entropy alloy nanocatalysts (HEAs), has revealed the possibilities of multielemental interactions that can surpass the limitations of binary and ternary electrocatalysts. The wide range of potential surface configurations in HEAs, however, presents a significant challenge in resolving active structural motifs, preventing the establishment of structure-function relationships for rational catalyst design and optimization. We present a methodology for creating sub-5 nm HEAs using an aqueous-based peptide-directed route.
View Article and Find Full Text PDFSoft materials in nature are formed through reversible supramolecular assembly of biological polymers into dynamic hierarchical networks. Rational design has led to self-assembling peptides with structural similarities to natural materials. However, recreating the dynamic functional properties inherent to natural systems remains challenging.
View Article and Find Full Text PDFIn vitro cell models have undergone a shift from 2D models on glass slides to 3D models that better reflect the native 3D microenvironment. 3D bioprinting promises to progress the field by allowing the high-throughput production of reproducible cell-laden structures with high fidelity. The current stiffness range of printable matrices surrounding the cells that mimic the extracellular matrix environment remains limited.
View Article and Find Full Text PDFNanoparticle-based magnetic contrast agents have opened the potential for magnetic resonance imaging (MRI) to be used for early non-invasive diagnosis of Alzheimer's disease (AD). Accumulation of amyloid pathology in the brain has shown association with cognitive decline and tauopathy; hence, it is an effective biomarker for the early detection of AD. The aim of this study was to develop a biocompatible magnetic nanoparticle targeted to amyloid beta (A) plaques to increase the sensitivity of T2-weighted MRI for imaging of amyloid pathology in AD.
View Article and Find Full Text PDFAffinity biosensors play a crucial role in clinical diagnosis, pharmaceuticals, immunology, and other areas of human health. Affinity biosensors rely on the specific binding between target analytes and biological ligands such as antibodies, nucleic acids, aptamers, or other receptors to primarily generate electrochemical or optical signals. Considerable effort has been put into improving the performance of the affinity technologies to make them more sensitive, efficient and reproducible, of the many approaches electrokinetic phenomena are a viable option.
View Article and Find Full Text PDFBiosens Bioelectron
October 2023
Switchable fluorescent proteins, for which fluorescence can be switched ON and OFF, are widely used for molecule tracking and super resolution imaging. However, the robust use of the switchable fluorescent proteins is still limited as either the switching is not repeatable, or such switching requires irradiation with coupled lasers of different wavelengths. Herein, we report an electrochemical approach to reversible fluorescence switching for enhanced green fluorescent proteins (EGFP) on indium tin oxide coated glass.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
January 2023
Enzymes with multiple distinct active sites linked by substrate channels combined with control over the solution environment near the active sites enable the formation of complex products from simple reactants via the confinement of intermediates. We mimic this concept to facilitate the electrochemical carbon dioxide reduction reaction using nanoparticles with a core that produces intermediate CO at different rates and a porous copper shell. CO reacts at the core to produce CO which then diffuses through the Cu to give higher order hydrocarbon molecules.
View Article and Find Full Text PDFPlasmonic nanoparticles are finding applications within the single molecule sensing field in a "dimer" format, where interaction of the target with hairpin DNA causes a decrease in the interparticle distance, leading to a localized surface plasmon resonance shift. While this shift may be detected using spectroscopy, achieving statistical relevance requires the measurement of thousands of nanoparticle dimers and the timescales required for spectroscopic analysis are incompatible with point-of-care devices. However, using dark-field imaging of the dimer structures, simultaneous digital analysis of the plasmonic resonance shift after target interaction of thousands of dimer structures may be achieved in minutes.
View Article and Find Full Text PDFNanozymes mimic enzymes and that includes their selectivity. To achieve selectivity, significant inspiration for nanoparticle design can come from the geometric and molecular features that make enzymes selective catalysts. The two central features enzymes use are control over the arrangement of atoms in the active site and the placing of the active site down a nanoconfined substrate channel.
View Article and Find Full Text PDFObjective: To evaluate the effects of alfaxalone administered IM with or without buprenorphine or hydromorphone in healthy rabbits (Oryctolagus cuniculus).
Animals: 24 male rabbits undergoing elective orchiectomy between August 21, 2021, and November 6, 2021.
Procedures: In this controlled clinical trial, rabbits were randomly assigned to receive alfaxalone (4 mg/kg, IM) alone (group A; n = 8) or with buprenorphine (0.
Hydrogels that serve as native extracellular matrix (ECM) mimics are typically naturally derived hydrogels that are physically cross-linked ionic interactions. This means rapid gelation of synthetic polymers, which give control over the chemical and physical cues in hydrogel formation. Herein, we combine the best of both systems by developing a synthetic hydrogel with ionic cross-linking of block copolyelectrolytes to rapidly create hydrogels.
View Article and Find Full Text PDFGold coated magnetic nanoparticles (Au@MNPs), modified with DNA sequences give dispersible electrodes that can detect ultralow amounts of microRNAs and other nucleic acids but, as with most other sensors, they require calibration. Herein we show how to adapt a calibration free approach for electrochemical aptamer-based sensors on bulk electrodes to microRNA (miR-21) detection with methylene blue terminated DNA modified Au@MNPs. The electrochemical square wave voltammetry signal from the DNA-Au@MNPs when collected at a bulk electrode under magnetic control, decreases upon capture of miR-21.
View Article and Find Full Text PDFGlioblastoma is hard to be eradicated partly because of the obstructive blood-brain barrier (BBB) and the dynamic autophagy activities of glioblastoma. Here, hydroxychloroquine (HDX)-loaded yolk-shell upconversion nanoparticle (UCNP)@ZnCdS nanoparticle coating with the cyclic Arg-Gly-Asp (cRGD)-grafted glioblastoma cell membrane for near-infrared (NIR)-triggered treatment of glioblastoma is prepared for the first time. UCNPs@ZnCdS (abbreviated as YSN, yolk-shell nanoparticle) under NIR radiation will generate reactive oxygen species for imposing cytotoxicity.
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