Sensitive sensing of Hg(II) based on lattice B and surface F co-doped CeO: Synergies of catalysis and adsorption brought by doping site engineering.

Transition metal oxides are widely used in the detection of heavy metal ions (HMIs), and the co-doping strategy that introducing a variety of different dopant atoms to modify them can obtain a better detection performance. However, there is very little research on the co-doped transition metal oxides by non-metallic elements for electrochemical detection. Herein, boron (B) and fluorine (F) co-doped CeO nanomaterial (BFC) is constructed to serve as the electrochemically sensitive interface for the detection of Hg(II).

Nanoporous gold microelectrode for electrochemical sensing of As(III) in cellular environment.

The highly toxic arsenite (As(III)) could cause serious cytotoxicity on metabolism, resulting in several diseases. However, it is still a great challenge on the precise sensing of As(III) in complicated conditions, especially in cellular environment. In this work, a nanoporous gold microelectrode (NPG-μE) was fabricated by a simple electrochemical alloying/dealloying method and developed for the electroanalysis of As(III) in the lung cancer cellular (A549 cells) environment.

Highly sensitive and selective serotonin (5-HT) electrochemical sensor based on ultrafine FeO nanoparticles anchored on carbon spheres.

Neurotransmitter serotonin (5-HT) is involved in various physiological and pathological processes. Therefore, its highly sensitive and selective detection in human serum is of great significance for early diagnosis of disease. In this work, employing iron phthalocyanine as Fe source, ultrafine FeO nanoparticles anchored on carbon spheres (FeO/CSs) have been prepared, which exhibits an excellent electrochemical sensing performance toward 5-HT.

Integrating Dually Encapsulated Si Architecture and Dense Structural Engineering for Ultrahigh Volumetric and Areal Capacity of Lithium Storage.

High-theoretical-capacity silicon anodes hold promise in lithium-ion batteries (LIBs). Nevertheless, their huge volume expansion (∼300%) and poor conductivity show the need for the simultaneous introduction of low-density conductive carbon and nanosized Si to conquer the above issues, yet they result in low volumetric performance. Herein, we develop an integration strategy of a dually encapsulated Si structure and dense structural engineering to fabricate a three-dimensional (3D) highly dense TiCT MXene and graphene dual-encapsulated Si monolith architecture (HD-Si@TiCT@G).

Noble-metal-free FeO/CoS nanosheets with oxygen vacancies as an efficient electrocatalyst for highly sensitive electrochemical detection of As(III).

The electrochemical method for highly sensitive determination of arsenic(III) in real water samples with noble-metal-free nanomaterials is still a difficult but significant task. Here, an electrochemical sensor driven by noble-metal-free layered porous FeO/CoS nanosheets was successfully employed for As(III) analysis, which was prepared via a facile two-step method involves a hydrothermal treatment and a subsequent sulfurization process. As expected, the electrochemical detection of As(III) in 0.

Simultaneous electrochemical detection of guanine and adenine using reduced graphene oxide decorated with AuPt nanoclusters.

A rapid and sensitive electrochemical sensing platform is reported based on bimetallic gold-platinum nanoclusters (AuPtNCs) dispersed on reduced graphene oxide (rGO) for the simultaneous detection of guanine and adenine using square wave voltammetry (SWV). The synthesis of AuPtNCs-rGO nanocomposite was achieved by a simultaneous reduction of graphene oxide (GO) and metal ions (Au and Pt) in an aqueous solution. The developed AuPtNCs-rGO electrochemical sensor with the optimized 50:50 bimetallic (Au:Pt) nanoclusters exhibited an outstanding electrocatalytic performance towards the simultaneous oxidation of guanine and adenine without the aid of any enzymes or mediators in physiological pH.

Ultrahigh-Volumetric-Energy-Density Lithium-Sulfur Batteries with Lean Electrolyte Enabled by Cobalt-Doped MoSe/TiCT MXene Bifunctional Catalyst.

It is a significant challenge to design a dense high-sulfur-loaded cathode and meanwhile to acquire fast sulfur redox kinetics and suppress the heavy shuttling in the lean electrolyte, thus to acquire a high volumetric energy density without sacrificing gravimetric performance for realistic Li-S batteries (LSBs). Herein, we develop a cation-doping strategy to tailor the electronic structure and catalytic activity of MoSe that hybridized with conductive TiCT MXene, thus obtaining a Co-MoSe/MXene bifunctional catalyst as a high-efficient sulfur host. Combining a smart design of the dense sulfur structure, the as-fabricated highly dense S/Co-MoSe/MXene monolith cathode (density: 1.

Green, Template-Less Synthesis of Honeycomb-like Porous Micron-Sized Red Phosphorus for High-Performance Lithium Storage.

Large-volume-expansion-induced material pulverization severely limits the electrochemical performance of high-capacity red phosphorus (RP) in alkali-ion batteries. Honeycomb-like porous materials can effectively solve the issues due to their abundant interconnected pore structures. Nevertheless, it is difficult and greatly challenging to fabricate a honeycomb-like porous RP that has not yet been fabricated chemical synthesis.

Copper decorated with nanoporous gold by galvanic displacement acts as an efficient electrocatalyst for the electrochemical reduction of CO.

The reduction of carbon dioxide (CO2) is recognized as a key component in the synthesis of renewable carbon-containing fuels. Herein, we report on nanoporous gold (NPAu) decorated with copper atoms for the efficient electrochemical reduction of CO2. A facile and green galvanic displacement technique was developed to incorporate Cu onto the surface of the nanoporous gold-zinc (NPAuZn) electrode.

A Smartphone-Based Sensing System for On-Site Quantitation of Multiple Heavy Metal Ions Using Fluorescent Carbon Nanodots-Based Microarrays.

The development of cost-effective and versatile sensing system for simultaneous and rapid quantitation of multiple targets is highly demanded for environmental surveillance, food safety inspection, home healthcare, etc. This work reports on (1) paper-based microarrays relying on fluorescence turn-off of carbon nanodots (CDs) for analyte recognition and (2) a stand-alone smartphone-based portable reader (SBR) installed with a custom-designed APP (SBR-App), which can accurately and reproducibly acquire fluorescence change from the microarray chip, automatically report the results, generate and share the reports via wireless network. Simultaneous detection of Hg, Pb, and Cu in the Pearl River water samples was achieved with the reported sensing system.

Ultrahigh and Durable Volumetric Lithium/Sodium Storage Enabled by a Highly Dense Graphene-Encapsulated Nitrogen-Doped Carbon@Sn Compact Monolith.

Tin-based composites hold promise as anodes for high-capacity lithium/sodium-ion batteries (LIBs/SIBs); however, it is necessary to use carbon coated nanosized tin to solve the issues related to large volume changes during electrochemical cycling, thus leading to the low volumetric capacity for tin-based composites due to their low packing density. Herein, we design a highly dense graphene-encapsulated nitrogen-doped carbon@Sn (HD N-C@Sn/G) compact monolith with Sn nanoparticles double-encapsulated by N-C and graphene, which exhibits a high density of 2.6 g cm and a high conductivity of 212 S m.

Sensitive Electrochemical Detection of Nitric Oxide Release from Cardiac and Cancer Cells via a Hierarchical Nanoporous Gold Microelectrode.

The importance of nitric oxide (NO) in many biological processes has garnered increasing research interest in the design and development of efficient technologies for the sensitive detection of NO. Here we report on a novel gold microelectrode with a unique three-dimensional (3D) hierarchical nanoporous structure for the electrochemical sensing of NO, which was fabricated via a facile electrochemical alloying/dealloying method. Following the treatment, the electrochemically active surface area (ECSA) of the gold microelectrode was significantly increased by 22.

A 3D printed smartphone optosensing platform for point-of-need food safety inspection.

The deficiency in rapid and in-field detection methods and portable devices that are reliable, easy-to-use, and low cost, results in the difficulties to uphold the high safety standards in China. In this study, we introduce a rapid and cost-effective smartphone-based method for point-of-need food safety inspection, which employs aptamer-conjugated AuNPs as the colorimetric indicator, and a battery-powered optosensing accessory attached to the camera of a smartphone for transmission images capture. A user-friendly and easy-to-use Android application is developed for automatic digital image processing and result reporting.

Sensitive electrochemical detection of nitric oxide based on AuPt and reduced graphene oxide nanocomposites.

Since nitric oxide (NO) plays a critical role in many biological processes, its precise detection is essential toward an understanding of its specific functions. Here we report on a facile and environmentally compatible strategy for the construction of an electrochemical sensor based on reduced graphene oxide (rGO) and AuPt bimetallic nanoparticles. The prepared nanocomposites were further employed for the electroanalysis of NO using differential pulse voltammetry (DPV) and amperometric methods.

Rapid determination of dopamine in human plasma using a gold nanoparticle-based dual-mode sensing system.

Dopamine plays a very important role in biological systems and has a direct relationship with the ability of learning and cognition, human desires, feelings and mental state, as well as motor functions. Traditional methods for the detection of dopamine are complicated and time-consuming, therefore it is necessary to explore rapid and accurate detection of dopamine with high sensitivity and specificity. Herein we report a dual-mode system of colorimetric and fluorometric analyses based on gold nanoparticles (AuNPs) and aptamers specifically targeting dopamine.

Design and Electrochemical Study of Platinum-Based Nanomaterials for Sensitive Detection of Nitric Oxide in Biomedical Applications.

The extensive physiological and regulatory roles of nitric oxide (NO) have spurred the development of NO sensors, which are of critical importance in neuroscience and various medical applications. The development of electrochemical NO sensors is of significant importance, and has garnered a tremendous amount of attention due to their high sensitivity and selectivity, rapid response, low cost, miniaturization, and the possibility of real-time monitoring. Nanostructured platinum (Pt)-based materials have attracted considerable interest regarding their use in the design of electrochemical sensors for the detection of NO, due to their unique properties and the potential for new and innovative applications.

Iron Oxide with Different Crystal Phases (α- and γ-Fe2O3) in Electroanalysis and Ultrasensitive and Selective Detection of Lead(II): An Advancing Approach Using XPS and EXAFS.

Iron oxide with different crystal phases (α- and γ-Fe2O3) has been applied to electrode coatings and been demonstrated to ultrasensitive and selective electrochemical sensing toward heavy metal ions (e.g., Pb(II)).

A Versatile Environmental Impedimetric Sensor for Ultrasensitive Determination of Persistent Organic Pollutants (POPs) and Highly Toxic Inorganic Ions.

An impedimetric sensor for persistent toxic substances, including organic pollutants and toxic inorganic ions is presented. The persistent toxic substances are detected using an ultrasensitive technique that is based on electron-transfer blockage. This depends on the formation of guest-host complexes, hydrogen bonding, or a cyclodextrin (CD)-metal complex (M(OH)-β-CD) structure between the target pollutants and β-CD.

Facet-dependent stripping behavior of Cu2O microcrystals toward lead ions: a rational design for the determination of lead ions.

Facet-dependent stripping behavior in the determination of Pb(II): Well-defined Cu2O microcrystals with different structures show facet-dependent electrochemical behaviors toward heavy metal ions. This provides an important insight into the understanding the efficiency of facet-dependent properties of microcrystals on electroanalytical performance for the rational design of electrochemical analytical techniques for efficient detection of heavy metal ions.

Exploiting differential electrochemical stripping behaviors of Fe3O4 nanocrystals toward heavy metal ions by crystal cutting.

This study attempts to understand the intrinsic impact of different morphologies of nanocrystals on their electrochemical stripping behaviors toward heavy metal ions. Two differently shaped Fe3O4 nanocrystals, i.e.

Robust electrochemical analysis of As(III) integrating with interference tests: a case study in groundwater.

In Togtoh region of Inner Mongolia, northern China, groundwater encountered high concentrations As contamination (greater than 50 μg L(-1)) causes an increasing concern. This work demonstrates an electrochemical protocol for robust (efficient and accurate) determination of As(III) in Togtoh water samples using Au microwire electrode without the need of pretreatment or clean-up steps. Considering the complicated conditions of Togtoh water, the efficiency of Au microwire electrode was systematically evaluated by a series of interference tests, stability and reproducibility measurements.

Role of Fe(III) in preventing humic interference during As(III) detection on gold electrode: spectroscopic and voltammetric evidence.

A drawback of As(III) detection using square wave anodic stripping voltammetry (SWASV) is that it is susceptible to interferences from various metals or organic compounds, especially in real sample water. This study attempts to understand the interference of co-existing of Fe(III) and humic acid (HA) molecules to the electrochemical detection of As(III) using Fourier transform infrared (FTIR) spectrum and X-ray photoelectron spectroscopy (XPS). The electrochemical experiments include stripping of As(III) in the solutions containing HA with different concentrations, cyclic voltammetry in 0.

A molecular-gap device for specific determination of mercury ions.

Specific determination/monitoring of trace mercury ions (Hg(2+)) in environmental water is of significant importance for drinking safety. Complementarily to conventional inductively coupled plasma mass spectrometry and atomic emission/absorption spectroscopy, several methods, i.e.

SnO₂ tube-in-tube nanostructures: Cu@C nanocable templated synthesis and their mutual interferences between heavy metal ions revealed by stripping voltammetry.

SnO2 tube-in-tube nanostructures are synthesized using Cu@C nanocables as effective sacrificial templates. It is revealed by stripping voltammetry that SnO2 tube-in-tube nanostructures show excellent performances in the determination of heavy metal ions, which might be related to the extraordinary adsorbing capacities of the hollow structure to metal ions, i.e.