Surface Defect and Wettability Engineering of Porous SnO for Reliable Bioassays with High Selectivity and Wide Linear Dynamic Range.

Bioassay systems that can selectively detect biomarkers at both high and low levels are of great importance for clinical diagnosis. In this work, we report an enzyme electrode with an oxygen reduction reaction (ORR)-tolerant HO reduction property and an air-liquid-solid triphase interface microenvironment by regulating the surface defects and wettability of nanoporous tin oxide (SnO). The enzyme electrode allows the oxygen that is required for the oxidase catalytic reaction to be transported from the air phase to the reaction zone, which greatly enhances the enzymatic kinetics and increases the linear detection upper limit.

Oxygen Vacancy Engineering of FeO toward Oxygen-Tolerant Hydrogen Peroxide Reduction for Reliable Bioassays.

The accurate determination of hydrogen peroxide (HO), an important clinical disease relevant biomarker, is of great importance for the diagnosis and management of illnesses. By using the cathodic monitoring approach, HO can be accurately detected because interfering signals from easily oxidizable endogenous and exogenous species in biofluids can be avoided. However, the simultaneous occurrence of the oxygen reduction reaction (ORR) restricts the practical use of this cathodic method.

Engineering a Hollow Carbon Sphere-Based Triphase Microenvironment for Enhanced Enzymatic Reaction Kinetics and Bioassay Performance.

Electrochemical bioassays based on oxidase reactions are frequently used in biological sciences and medical industries. However, the enzymatic reaction kinetics are severely restricted by the poor solubility and slow diffusion rate of oxygen in conventional solid-liquid diphase reaction systems, which inevitably compromises the detection accuracy, linearity, and reliability of the oxidase-based bioassay. Herein, an effective solid-liquid-air triphase bioassay system is provided that uses hydrophobic hollow carbon spheres (HCSs) as oxygen nanocarriers.

Laser-Induced Graphene Arrays-Based Three-Phase Interface Enzyme Electrode for Reliable Bioassays.

Electrochemical oxidase biosensors have been widely applied in healthcare, environmental measurements and the biomedical field. However, the low and fluctuant oxygen levels in solution and the high anodic detection potentially restrict the assay accuracy. To address these problems, in this work, we constructed a three-phase interface enzyme electrode by sequentially immobilizing HO electrocatalysts and an oxidase layer on a superhydrophobic laser-induced graphene (LIG) array substrate.

High-Performance Photoelectrochemical Enzymatic Bioanalysis Based on a 3D Porous CuO@TiO Film with a Solid-Liquid-Air Triphase Interface.

The accurate detection of HO is crucial in oxidase-based cathodic photoelectrochemical enzymatic bioanalysis but will be easily compromised in the conventional photoelectrode-electrolyte diphase system due to the fluctuation of oxygen levels and the similar reduction potential between oxygen and HO. Herein, a solid-liquid-air triphase bio-photocathode based on a superhydrophobic three-dimensional (3D) porous micro-nano-hierarchical structured CuO@TiO film that was constructed by controlling the wettability of the electrode surface is reported. The triphase photoelectrochemical system ensures an oxygen-rich interface microenvironment with constant and sufficiently high oxygen concentration.

Three-Phases Interface Induced Local Alkalinity Generation Enables Electrocatalytic Glucose Oxidation in Neutral Electrolyte.

Electrocatalytic glucose oxidation is crucial to the development of non-enzymatic sensors, an attractive alternative for enzymatic biosensors. However, due to OH consumption during the catalytic process, non-enzymatic detection generally requires electrolytes having an alkaline pH value, limiting its practical application since biofluids are neutral. Herein, interfacial microenvironment design, we addressed this limitation by developing a non-enzymatic sensor with an air-solid-liquid triphase interface electrodes that synergistically integrates the functions of local alkalinity generation and electrocatalytic glucose oxidation.

Decoupling hydrogen production from water oxidation by integrating a triphase interfacial bioelectrochemical cascade reaction.

Water electrolysis to produce H is a promising strategy for generating a renewable fuel. However, the sluggish-kinetics and low value-added anodic oxygen evolution reaction (OER) restricts the overall energy conversion efficiency. Herein we report a strategy of boosting H production at low voltages by replacing OER with a bioelectrochemical cascade reaction at a triphase bioanode.

Increasing the Efficiency of Photocatalytic Reactions via Surface Microenvironment Engineering.

The use of photocatalysis for water purification and environmental protection is of key interest. However, the reaction kinetics can be limited by the restricted accessibility of electron acceptor oxygen and the low adsorption of organic compounds-crucial factors underlying photocatalytic performance. Here we simultaneously alleviate these constraints via reaction interface microenvironment design using superhydrophobic (SHB) TiO nanoarrays as a model photocatalyst.

Oxygen-Tolerant Hydrogen Peroxide Reduction Catalysts for Reliable Noninvasive Bioassays.

Noninvasive bioassays based on the principle of a hydrogen peroxide (H O ) cathodic reaction are highly desirable for low concentration analyte detection within biofluids since the reaction is immune to interference from oxidizable species. However, the inability to selectively reduce H O over O for commonly used stable catalysts (carbon or noble metals) is one of the key factors limiting their development and practical applications. Herein, catalysts that enable selective H O reduction in the presence of oxygen with fluctuating concentrations are reported.

Controlled synthesis of BiO/TiO catalysts with mixed alcohols for the photocatalytic oxidation of HCHO.

BiO/TiO photocatalysts were prepared by a hydrothermal method. The photocatalysts were applied to the catalytic oxidation of indoor formaldehyde vapors under irradiation by an light-emitting diode energy-saving lamp. The characterization methods including Brunauer-Emmett-Teller, X-ay diffraction, UV-vis spectra, scanning electron microscopy, Transmission electron microscopy and X-ray photoelectron spectroscopy analysis were used to investigate the crystalline structure, morphology, specific surface area and porosity.