Single iron catalyst with bi-atomic matching site to construct electrochemical chip for on-site inspection of antibiotic chloramphenicol.

Chloramphenicol (CAP) as an amide-alcohol antibiotic is extensively used in aquaculture industries and can accumulate in the human body through the food chain and water sources, leading to various diseases. On-site inspection of CAP remains a challenge due to the lack of portable and sensitive sensing platforms. Herein, a bi-atomic matching catalyst that comprises atomic Fe uniformly distributed on an N-doped graphene matrix (A-Fe-NG) is synthesized.

Implementation of π-π interaction in AuNPs@GDY to boost the bioelectrocatalysis in enzymatic biofuel cells.

The main challenges (sluggish electron transfer, low energy density) hinder the future application of enzymatic biofuel cells (EBFCs), which urgent to take effective measures to solve these issues. In this work, a composite of Au nanoparticles decorated graphdiyne (AuNPs@GDY) is fabricated and employed as the carrier of enzyme (G6PDH), and a mechanism based on π-π interaction of electron transfer is proposed to understand bioelectrocatalysis processes. The results show that the AuNPs@GDY composite exhibits the highest current density among the three materials (GDY, AuNPs, and AuNPs@GDY), which is 3.

Electromagnetic Field Drives the Bioelectrocatalysis of γ-FeO-Coated CN32 to Boost Extracellular Electron Transfer.

The microbial hybrid system modified by magnetic nanomaterials can enhance the interfacial electron transfer and energy conversion under the stimulation of a magnetic field. However, the bioelectrocatalytic performance of a hybrid system still needs to be improved, and the mechanism of magnetic field-induced bioelectrocatalytic enhancements is still unclear. In this work, γ-FeO magnetic nanoparticles were coated on a CN32 cell surface and followed by placing in an electromagnetic field.

Graphdiyne marries PEDOT:PSS to form high-stable heterostructure from 2-unstable components toward ultra-low detection limit of uric acid detection in sweat.

PSS has been used as a biomimetic uric acid (UA) sensor but suffers from unfortunate low detection limit (LOD), narrow detection range and poor stability. Herein, we get graphdiyne (GDY) marry PEDOT:PSS to create a very stable GDY@PEDOT:PSS heterostructure for a biomimetic UA sensor, which accomplishes the lowest LOD (6 nM), the widest detection range (0.03 μM-7 mM) and the longest stability (98.

Tuning metal atom doped interface of electrospinning nanowires to toward fast bioelectrocatalysis.

Metal doping plays a key role in overcoming inefficient extracellular electron transfer between electrode interface and electricity-producing microorganisms. However, it is unknown whether different metals play distinctive roles in the doping process. Herein, three different metal ions (Fe, Ni and Cu) are added to the spinning precursor to obtain the corresponding electrospinning metal doped carbon nanofibers.

Integrated Sandwich-Paper 3D Cell Sensing Device to Wirelessly Monitor HO Released from Living Cells.

Point-of-care testing (POCT) has attracted great interest because of its prominent advantages of rapidness, precision, portability, and real-time monitoring, thus becoming a powerful biomedical device in early clinical diagnosis and convenient medical treatments. However, its complicated manufacturing process and high expense severely impede mass production and broad applications. Herein, an innovative but inexpensive integrated sandwich-paper three-dimensional (3D) cell sensing device is fabricated to wirelessly detect HO released from living cells.

Graphdiyne chelated AuNPs for ultrasensitive electrochemical detection of tyrosine.

Tyrosine (Tyr) is a kind of amino acid that can regulate emotions and stimulate the nervous system, and it is of great importance to realize its ultrasensitive detection. A unique material of graphdiyne chelated AuNPs (GDY@AuNPs) is designed and developed to realize high-performance electrochemical sensing of Tyr. GDY promotes the absorption of Tyr π-π interaction, and its CC strongly chelates with AuNPs for greatly improved sensitivity.

The Enhancement Mechanism of Different Single-Transition Metal Atomic Catalysts/Sulfur Cathode on High-Performance of Li-S Batteries.

Materials with various single-transition metal atoms dispersed in nitrogenated carbons (M─N─C, M = Fe, Co, and Ni) are synthesized as cathodes to investigate the electrocatalytic behaviors focusing on their enhancement mechanism for performance of Li-S batteries. Results indicate that the order of both electrocatalytic activity and rate capacity for the M─N─C catalysts is Co > Ni > Fe, and the Co─N─C delivers the highest capacity of 1100 mAh g at 1 C and longtime stability at a decay rate of 0.05% per cycle for 1000 cycles, demonstrating excellent battery performance.

Doping molybdenum oxides with different non-metal atoms to promote bioelectrocatalysis in microbial fuel cells.

The sluggish extracellular electron transfer has been known as one of the bottlenecks to limit the power density of microbial fuel cells (MFCs). Herein, molybdenum oxides (MoO) are doped with various types of non-metal atoms (N, P, and S) by electrostatic adsorption, followed by high-temperature carbonization. The as-prepared material is further used as MFC anode.

Electrospinning Mo-Doped Carbon Nanofibers as an Anode to Simultaneously Boost Bioelectrocatalysis and Extracellular Electron Transfer in Microbial Fuel Cells.

The sluggish electron transfer at the interface of microorganisms and an electrode is a bottleneck of increasing the output power density of microbial fuel cells (MFCs). Mo-doped carbon nanofibers (Mo-CNFs) prepared with electrostatic spinning and high-temperature carbonization are used as an anode in MFCs here. Results clearly indicate that MoC nanoparticles uniformly anchored on carbon nanowire, and Mo-doped anodes could accelerate the electron transfer rate.

Interfacial Regulation of ZIF-67 on Bacteria to Generate Bifunctional Sensing Material on Chip for Qualifying Cell-Released Reactive Oxygen Species.

Cell's activities are highly dependent on signal molecules, of which reactive oxygen species of the superoxide anion (O) and hydrogen peroxide (HO) are important ones that always work together to regulate biological processes such as apoptosis and oxidative stress. It is of significance to realize simultaneous qualification of O and HO but it still faces challenges particularly in live-cell assay with a complex environment. We report the design of a bifunctional sensing material by interfacially regulating ZIF-67 on bacteria to generate cobalt nanoparticles/nitrogen-doped porous carbon nanorods (Co/N-doped CNRs) and its sensing chip for qualifying cell-released O and HO.

Synthesis of NiO/Nitrogen-Doped Carbon Nanowire Composite with Multi-Layered Network Structure and Its Enhanced Electrochemical Performance for Supercapacitor Application.

Multi-layered NiO nanowires linked with a nitrogen-doped carbon backbone grown directly on flexible carbon cloth (NiO/NCBN/CC) was successfully fabricated with a facile synthetic strategy. The NiO/NCBN/CC was further used as a binding-free electrode for flexible energy storage devices, showing a boosted performance including a high capacitance of 1039.4 F g at 1 A g and an 83.

Assess heavy metals-induced oxidative stress of microalgae by Electro-Raman combined technique.

Oxidative stress of aquatic microorganisms under heavy metal stress is closely reflected by metabolite changes in cells but it is very difficult to study due to the fast metabolism process and severe in-situ measurements hurdle. Herein, the oxidative stress of cadmium on Euglena gracilis was systematically studied through multi-combined techniques. In particular, for the first time electrochemical approach was associated with Raman spectroscopy imaging to vividly to investigate temporal-spatially varied oxidative stress and its effects on cells metabolism, in which former real-time measured a volcanic relation of extracellular hydrogen peroxide versus the increase of cadmium stress, while the latter shows the corresponding metabolic changes by Raman imaging of single cells.

Vanadium pentoxide flat-nanofiber networked thin layer-structure to initiate intercalated polymerization for rapidly producing superior conductive hydrogel and its biomimetic hydrogen peroxide sensing application.

Poly(3,4-ethylenedioxythiophene) (PEDOT)-based hydrogel has been studied extensively due to its low cost, good chemical/mechanical stability, printability and high biocompatibility, but still suffers from its relatively low conductivity and complex synthesis method. In this work, we use vanadium pentoxide (VO) flat-nanofiber networked thin layer-structure to boost EDOT-intercalation reaction for rapidly producing fiber-reinforced conductive gel (FCG), achieving superior conductivity of 10 S cm and extremely fast production time (10 s). The superior FCG formation mechanism is ascribed to the VO flat-nanofiber networked thin layer-structure allowing EDOT rapidly penetrating to inter-layers and replacing inside water molecules for polymerization to high-conductive FCG.

Highly stable branched cationic polymer-functionalized black phosphorus electrochemical sensor for fast and direct ultratrace detection of copper ion.

Copper ions (Cu) is an indispensable trace element in the process of metabolism and intake of excessive Cu may lead to fatal diseases such as Alzheimer's disease. It is highly demanding to develop a sensitive, selective and convenient method for Cu detection. In this work, thin-layer structured polyethyleneimine (PEI) decorated black phosphorus (BP) nanocomposite is one-step synthesized for an electrochemical sensor toward direct detection of Cu.

Screen-printed analytical strip constructed with bacteria-templated porous N-doped carbon nanorods/Au nanoparticles for sensitive electrochemical detection of dopamine molecules.

Dopamine (DA) as an important neurotransmitter plays an important role in physiological activities, and its abnormal level can cause diseases such as Parkinson's disease. However, the clinical analysis of DA mainly relies on time-consuming and expensive liquid chromatography and molecular spectrometer. We present here a design and fabrication of inexpensive strip sensor constructed from screen printed electrodes for sensitive and selective detection of DA.

Derivation of empirical model to predict the accumulation of Pb in rice grain.

Lead contamination in soil has become a worldwide threat on food security and human health. To assess the Pb bioavailability and evaluate the safe use of low Pb polluted soil for food production, the speciation of Pb in 19 types of paddy soil were investigated by chemical extraction and X-ray absorption near-edge structure (XANES), and the uptake and accumulation characteristics of Pb in different soil-rice systems were investigated. Moreover, an empirical model was established to predict the content of Pb in rice grain, and field validation was conduct to evaluate model performance.

Controlling Factors and Prediction of Lead Uptake and Accumulation in Various Soil-Pepper Systems.

Lead (Pb) is a typical toxic heavy metal element in soils and plants, which has a potential threat to human health through the food chain. Uptake of Pb in the soil-vegetable system has attracted broad attention, whereas reports on the main controlling factors of Pb uptake and accumulation in different soil-vegetable systems are limited. The effect of soil properties on Pb uptake and accumulation in pepper (Capsicum annuum L.

Wheat (Triticum aestivum L.) grains uptake of lead (Pb), transfer factors and prediction models for various types of soils from China.

Lead (Pb) contaminated in farmlands has become a deep threat to global food security and human health. In this study, the bioavailability of Pb in 18 types of soil to wheat (Triticum aestivum L.) grains were investigated, and reliable empirical models of Pb in wheat grains were established based on soil properties.

Nitrogen doping to atomically match reaction sites in microbial fuel cells.

Direct electron transfer at microbial anodes offers high energy conversion efficiency but relies on low concentrations of redox centers on bacterium membranes resulting in low power density. Here a heat-treatment is used to delicately tune nitrogen-doping for atomic matching with Flavin (a diffusive mediator) reaction sites resulting in strong adsorption and conversion of diffusive mediators to anchored redox centers. This impregnates highly concentrated fixed redox centers in the microbes-loaded biofilm electrode.

Electrical tension-triggered conversion of anaerobic to aerobic respiration of Shewanella putrefaciens CN32 cells while promoting biofilm growth in microbial fuel cells.

A global gene expression analysis of Shewanella putrefaciens CN32 cells nearby a nanostructured microbial anode reveals an electrical tension-triggered conversion of anaerobic respiration to aerobic respiration with increased excretion of flavin electron shuttles and cytochrome C proteins, which sheds light on the role of electric tension in cell organisms.

Atomic matching catalysis to realize a highly selective and sensitive biomimetic uric acid sensor.

A main challenge for biomimetic non-enzyme biosensors is to achieve high selectivity. Herein, an innovative biomimetic non-enzyme sensor for electrochemical detection of uric acid (UA) with high selectivity and sensitivity is realized by growing Prussian blue (PB) nanoparticles on nitrogen-doped carbon nanotubes (N-doped CNTs). The enhancement mechanism of the biomimetic UA sensor is proposed to be atomically matched active sites between two reaction sites (oxygen atoms of 2, 8-trione, 6.

Fast Start-Up Microfluidic Microbial Fuel Cells With Serpentine Microchannel.

Microfluidic microbial fuel cells (MMFCs) are promising green power sources for future ultra-small electronic devices. The MMFCs with co-laminar microfluidic structure are superior to other MMFCs according to their low internal resistance and relative high power density. However, the area for interfacial electron transfer between the bacteria and the anode is quite limited in the typical Y-shaped device, which apparently restricts the current generation performance.

Flexible electronic skin with nanostructured interfaces via flipping over electroless deposited metal electrodes.

A novel and simple method was developed to quickly pattern and transfer electrodes with nanostructures for fabricating flexible electronic skin (E-skin). A nano/micro-structure embedded Cu electrode can be fabricated from a solution process-based electroless deposition (ELD) on a frosted plastic substrate and subsequently flipped over with an adhesive tape. The fine nano/microstructures on the Cu layer benefit the pressure-electric response of the pressure sensor, demonstrated a high sensitivity: 2.

Hierarchically Porous N-Doped Carbon Nanotubes/Reduced Graphene Oxide Composite for Promoting Flavin-Based Interfacial Electron Transfer in Microbial Fuel Cells.

Interfacial electron transfer between an electroactive biofilm and an electrode is a crucial step for microbial fuel cells (MFCs) and other bio-electrochemical systems. Here, a hierarchically porous nitrogen-doped carbon nanotubes (CNTs)/reduced graphene oxide (rGO) composite with polyaniline as the nitrogen source has been developed for the MFC anode. This composite possesses a nitrogen atom-doped surface for improved flavin redox reaction and a three-dimensional hierarchically porous structure for rich bacterial biofilm growth.