Homogeneous electrochemical sensing is a modification-free approach, in which the biochemical reactions occur in a homogeneous solution rather than on a limited electrode interface. Homogeneous sensing strategies are high-efficient but yet suffer from high background signals, since the free indicators can diffuse upon the electrode to generate signals. In this work, a magnetic graphene oxide (M-GO)

In this work, we have developed an antifouling carbon surface by hydrogenating it using n-butylsilane reduction. After incubating physically small electrodes with such an antifouling carbon surface for 30 min in a synthetic fouling solution containing 1.0 % (v/v) caproic acid (a lipid), 4 % (w/v) bovine serum albumin and 0.01 % (w/v) cytochrome c (both are proteins), and 0.002 % (w/v) human fibrinopeptide

A novel micro-needle sensor based on gold nanoclusters (AuNCs) immobilized with conducting polymer film poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT-PSS) was fabricated for determination of iron in coastal waters. The unique aciform structure of the micro-needle electrode (MNE) provided larger specific surface area than common electrodes. The surface modification of MNE with

ZnO-nanoparticles (NPs) were investigated for improving the response characteristics of a Pd-functionalized AlGaN/GaN heterojunction-based hydrogen gas sensor. The ZnO-NPs of diameter ∼10 nm were dispersed in a co-solvent of chloroform/ethanol (chloroform 75%, v/v), which was found to be an optimal solution for uniform dispersion, and spin coated on the surface of the fabricated Pd/AlGaN/GaN hydrogen

High-sensitivity and inexpensive humidity sensors with rapid response are crucial for humidity detection. In this study, a quartz crystal microbalance (QCM) sensor based on nitro-modified cellulose nanocrystals (NCNCs) films were developed for rapid and sensitive detection of humidity. The NCNCs films with good hydrophilicity along with fast water adsorption and dehydration were used as the humidity

There is an urgent need of label-free technique with low limit of detection (LOD) for biomedical research and early clinical diagnostics. Surface plasmon resonance (SPR) as a label-free approach has been exploited in DNA determination, but the LOD of most SPR sensors is inferior to labeling approaches. A novel approach for SPR biosensing with low LOD was reported in the present study. SPR for long

A glassy carbon electrode (GCE) was decorated with polyaniline, ZrO2-SO42− and multi walled carbon nanotubes (MWCNT) nanostructures to supply a sensor devise for Cr(VI) ions measurement, here. The aniline was polymerized in phosphoric acid solution by using peroxydisulfate as an initiator. ZrO2-SO42− nanostructures were synthesized by mono ethanolamine as reducing agent. The fabricated [email protected]2-SO42-@MWCNT

On-site monitoring of l-cysteine (L-Cys) has great significance for clinical diagnosis. In this study, a portable, fast, and ultrasensitive self-powered biosensor based on the single-chamber glucose/air enzymatic biofuel cell (EBFC) is proposed for the detection of l-Cys. Gold nanoparticles (AuNPs) and ultrathin hollow carbon shells (UHCS) were prepared and used as the biocathode and bioanode base

A paper-based analytical device (PADs) combined with a powerful chemiluminescence (CL) system was established for the determination of deltamethrin (DM), based on the enhancing effect of polyphosphate (PP) on graphene quantum dots (GQDs)-KMnO4 CL reaction. A possible mechanism for the obtained emission was proposed using the CL spectra, fluorescence and ultraviolet-visible patterns. The reaction of

The development of low cost, efficient and reversible chemiresistive sensors is one of the future challenges for the detection of harmful and toxic gases. In this direction, the effect of anchoring of hexadecafluorinated copper phthalocyanine (F16CuPc) molecules on to the reduced graphene oxide (rGO) sheets has been investigated for the first time, to develop a room-temperature chemiresistive sensor

Real-time gas classification is an essential issue and challenge in applications such as food and beverage quality control, accident prevention in industrial environments, for instance. In recent years, the Deep Learning (DL) models have shown great potential to classify and forecast data in diverse problems, even in the electronic nose (E-Nose) field. In this work, a Support Vector Machine (SVM) algorithm

Dielectrophoresis (DEP) has emerged as a viable means of fabricating functional materials and devices via self-assembly of colloidal particles, and has attracted much attention. Despite the extensive studies, how the crossover frequency of a pearl chain changes with the number of forming spheres is still unclear. Here we investigate the crossover frequency of individual two-sphere particles using the

Fluorescent copper microspheres (CMS) with high quantum yield (72.9 %) were synthesized by an efficient, one-pot, and rapid aggression-induced mechanism. The CMS was bright brick-red luminescent under UV light and have shown an excitation independent emission at 670 nm. The emission intensity of CMS was significantly quenched by the addition of nicotinamide adenine dinucleotide (NADH) when excited

We report the sensing performance of In2O3 nanoparticles (NPs) synthesized by a co-precipitation method for the detection of isoprene. The as-synthesized In2O3 NPs exhibited excellent isoprene-sensing performance compared to other previously reported isoprene sensors based on metal-oxide semiconductors. Under an exposure of 1 ppm isoprene at an optimal operating temperature of 350 ℃, the In2O3 NP sensor

In this study, we present the microfabrication and characterization of a transparent microelectrode array (MEA) system based on PEDOT:PSS for electrophysiology. The influence of the PEDOT:PSS electrode dimensions on the impedance was investigated and the stability over time under physiological environment was demonstrated. A very good transparency value was obtained by our system displaying one of

Biosensors play a key role in almost every field of human activity – ranging from biomedical diagnosis and point-of-care health monitoring to environmental monitoring and forensics. Single-walled carbon nanotubes (SWCNTs) are one of the most promising materials for near-infrared (NIR) fluorescence-based biosensing. Herein, we develop a reusable, drop-casted, real-time optical biosensor based on peptide-encapsulated

Capacitive micromachined ultrasonic transducer (CMUT) is a proven MEMS based gravimetric sensor featuring high mass sensitivity. It can be highly sensitive for relative humidity (RH) measurement when drop-casted with moisture-sensitive graphene oxide (GO) film. However, high hysteresis appears to be a critical problem for the sensor partially due to the non-uniformity of the sensing film. Here, we

Despite the tremendous achievements of existing point-of-care testing (POCT) techniques, accurate on-site detection of pesticide remains a thorny issue. Herein, the concept of multi-enzyme cascade system-based hydrogel kit integrated with a smartphone detector for in-field screening of pesticide was proposed. In this work, we constructed a target-responsive hydrogel (TRhg)-based kit by embedding MnO2

In this study, we demonstrated a limiting current-type yttria-stabilized zirconia thin-film oxygen sensor with a gas diffusion layer composed of porous Pt and spiral Ta2O5, which were deposited via sputtering and rotational oblique evaporation, respectively. The rate of the oxygen gas diffusion through the porous Pt and spiral Ta2O5 films defined the limiting current level of the oxygen sensor. When

As a new member of the MXene family, two dimensional (2D) niobium carbide MXene (Nb2CTx) holds a promising potential in gas detection due to the abundant surface terminated groups and large specific surface area. In this work, a selective NH3 sensor based on polyaniline (PANI) nanofibers-supported Nb2CTx nanosheets (Nb2CTx/PANI) directly driven by a facile triboelectric nanogenerator (TENG) is proposed

Breath analysis is of great significance for the early diagnosis of diabetic ketoacidosis. Gas sensors with simple structure and low cost have become candidates for breath analysis. The detection range and reliability of the device play an important role in the actual application. In this work, we used Bi1-xSrxFeO3 (x = 0.2, 0.4, 0.6, 0.8) prepared by sol-gel method to fabricate Ce0.8Gd0.2O1.95 (GDC)-based

A screening method for the highly toxic nerve agent VX is required for forensic and clinical analysis. In this study, a simple colorimetric method using gold nanoparticles (AuNPs) was established as an efficient strategy for VX detection by the naked eye. The AuNPs changed from bright red to deep blue on addition of VX under weakly acidic conditions. In the presence of 2-(diisopropylamino)ethanethiol

Nano-sized lipid vesicles (50–300 nm in diameter) are widely used in drug delivery systems and cosmetics. Recently, exosomes have been shown to be important as the carriers of biomolecules. The membrane structures of exosomes exhibit the same asymmetric lipid distributions as those of the plasma membranes of eukaryotic cells. The asymmetric lipid distributions of the exosome membranes play a key role

Nucleic acid detection is important for clinical diagnostics; however, it is challenging to perform genetic testing at the point-of-care due to the tedious steps involved in DNA extraction and the risk of cross-contamination from amplicons. To achieve a fully-automated and contamination-free nucleic acid detection, we propose a closed-type cassette system which enables the following steps to be operated

Conquering the issue of room temperature H2 detection at ppm/ppb level and their fundamental sensing mechanism are vitally needed for the development of highly sensitive/selective sensing devices. Herein, a strategy is proposed to synthesize 2D ZnO holey nanosheets by engineering the tunable pore/hole size with controlled oxygen vacancies using the annealing process for H2 detection at room temperature

Increased oxidative burden contributes to the pathogenesis of most inflammatory diseases and is associated with aging and chronic inflammation. Macrophages contribute to the generation of reactive oxygen species (ROS) within inflamed tissues. Currently, ROS generation is measured using fluorescent probes and colorimetric/fluorimetric biochemical assays. Hydrogen peroxide (H2O2) diffuses through the