Rapid and Continuous Simultaneous Monitoring of Interleukin-6 and Lactate Using a Bioelectronic Sensor Platform: toward Early Sepsis Prediction.

Timely and precise monitoring of inflammatory biomarkers is essential for the effective management of sepsis and related acute conditions. Current monitoring strategies depend mostly on centralized, benchtop systems. Here, we present compact and bioelectronic sensor platforms capable of rapid and simultaneous detection of lactate and interleukin-6 (IL-6) in human serum and interstitial fluid.

A Touch Enabled Hemodynamic and Metabolic Monitor.

Accurate health analysis demands real-time tracking of multiple biomarkers and vital signs under dynamic physiological conditions. Current multimodal hybrid platforms provide biochemical and biophysical data but are limited by active sweat collection for biochemical sensing and bulky designs for biophysical sensing. Here a touch-enabled platform is presented that simultaneously monitors vitals and metabolic markers.

Biomimetic Cell Membrane Layers for the Detection of Insulin and Glucagon.

The growing need for reliable and rapid insulin testing to enhance glycemic management has spurred intensive exploration of new insulin-binding bioreceptors and innovative biosensing platforms for detecting this hormone, along with glucagon, in biological samples. Here, by leveraging the native protein receptors on the HepG2 cell membrane, we construct a simple and chemical-free biomimetic molecular recognition layer for the detection of insulin and glucagon. Unlike traditional affinity sensors, which require lengthy surface modifications on the electrochemical transducers and use of two different capture antibodies to recognize each analyte, this new biomimetic sensing strategy employs a simple drop-casting of a natural cell membrane recognition layer onto the electrochemical transducer.

Simultaneous and Rapid Detection of Glucose and Insulin: Coupling Enzymatic and Aptamer-Based Assays.

Diabetes management demands precise monitoring of key biomarkers, particularly insulin (I) and glucose (G). Herein, we present a bioelectronic chip device that enables the simultaneous detection of I and G in biofluids within 2 min. This dual biosensor chip integrates aptamer-based insulin sensing with enzymatic glucose detection on a single platform, employing a four-electrode sensor chip.

Decentralized ORP Measurements for Gut Redox Status Monitoring: Toward Personalized Gut Microbiota Balance.

Gut microbiome targeting has emerged as a new generation of personalized medicine and a potential wellness and disease driver. Specifically, the gut redox balance plays a key role in shaping the gut microbiota and its link with the host, immune system, and disease evolution. In this sense, precise and personalized nutrition has proven synergy and capability to modulate the gut microbiome environment through the formulation of dietary interventions, such as vitamin support.

Insulin detection in diabetes mellitus: challenges and new prospects.

Tremendous progress has been made towards achieving tight glycaemic control in individuals with diabetes mellitus through the use of frequent or continuous glucose measurements. However, in patients who require insulin, accurate dosing must consider multiple factors that affect insulin sensitivity and modulate insulin bolus needs. Accordingly, an urgent need exists for frequent and real-time insulin measurements to closely track the dynamic blood concentration of insulin during insulin therapy and guide optimal insulin dosing.

Rapid nanocatalytic reaction using antibody-conjugated gold nanoparticles for simple and sensitive detection of parathyroid hormone.

Biomolecule-conjugated metal nanoparticles (NPs) have been primarily used as colorimetric labels in affinity-based bioassays for point-of-care testing. A facile electrochemical detection scheme using a rapid nanocatalytic reaction of a metal NP label is required to achieve more quantitative and sensitive point-of-care testing. Moreover, all the involved components should be stable in their dried form and solution.

Dicarboxylate-containing and fully substituted ferrocene with rapid dissolvability, high solubility, good stability, and moderate formal potential for mediated electrochemical detection.

An electron mediator with rapid dissolvability and high solubility in aqueous electrolyte solutions is essential for point-of-care testing based on mediated electrochemical detection. However, most ferrocenyl (Fc) compounds have slow dissolvability and poor solubility owing to high hydrophobicity of the Fc backbone. Moreover, many Fc compounds have poor stability and nonoptimal formal potential ().

Wash-Free, Sandwich-Type Protein Detection Using Direct Electron Transfer and Catalytic Signal Amplification of Multiple Redox Labels.

Direct electron transfer (DET) between a redox label and an electrode has been used for sensitive and selective sandwich-type detection without a wash step. However, applying DET is still highly challenging in protein detection, and a single redox label per probe is insufficient to obtain a high electrochemical signal. Here, we report a wash-free, sandwich-type detection of thrombin using DET and catalytic signal amplification of multiple redox labels.

Di(Thioether Sulfonate)-Substituted Quinolinedione as a Rapidly Dissoluble and Stable Electron Mediator and Its Application in Sensitive Biosensors.

The commonly required properties of diffusive electron mediators for point-of-care testing are rapid dissolubility, high stability, and moderate formal potential in aqueous solutions. Inspired by nature, various quinone-containing electron mediators have been developed; however, satisfying all these requirements remains a challenge. Herein, a strategic design toward quinones incorporating sulfonated thioether and nitrogen-containing heteroarene moieties as solubilizing, stabilizing, and formal potential-modulating groups is reported.

Solid-phase recombinase polymerase amplification using an extremely low concentration of a solution primer for sensitive electrochemical detection of hepatitis B viral DNA.

Recombinase polymerase amplification (RPA) is considered one of the best amplification methods for realizing a miniaturized diagnostic instrument; however, it is notably challenging to obtain low detection limits in solid-phase RPA. To overcome these difficulties, we combined solid-phase RPA with electrochemical detection and used a new concentration combination of three primers (surface-bound forward primer, solution reverse primer, and an extremely low concentration of solution forward primer). When solid-phase RPA was performed on an indium tin oxide (ITO) electrode modified with a surface-bound forward primer in a solution containing a biotin-terminated solution reverse primer, an extremely low concentration of a solution forward primer, and a template DNA or genomic DNA for a target gene of hepatitis B virus (HBV), amplification occurred mainly in solution until all the solution forward primers were consumed.

Electrochemical immunoassay based on choline oxidase-peroxidase enzymatic cascade.

Horseradish peroxidase (HRP)-based electrochemical immunoassays are considered promising techniques for point-of-care clinical diagnostics, but the necessary addition of unstable HO in the enzymatic system may hinder their practical application. Although glucose oxidase (GOx) has been widely explored for in situ generation of HO in HRP-based immunoassay, the GOx-catalyzed reduction of oxidized peroxidase substrate may limit the immunosensing performance. Here, we report a sensitive electrochemical immunosensor based on a choline oxidase (ChOx)-HRP cascade reaction.

Boosting electrochemical immunosensing performance by employing acetaminophen as a peroxidase substrate.

In horseradish peroxidase (HRP)-based electrochemical immunosensing, an appropriate HRP substrate needs to be chosen to obtain a high electrochemical signal-to-background ratio. This is limited by the unwanted electrochemical reduction of HO, oxidation of the substrate, and the slow electrochemical reduction of the product. Herein, we report acetaminophen (AMP) as a new HRP substrate that allows for highly sensitive immunosensing.

Use of a Phosphatase-Like DT-Diaphorase Label for the Detection of Outer Membrane Vesicles.

DT-diaphorase (DT-D) is known to mainly catalyze the two-electron reduction of quinones and nitro(so) compounds. Detection of Gram-negative bacterial outer membrane vesicles (OMVs) that contain pyrogenic lipopolysaccharides (LPSs, also called endotoxins) is required for evaluating the toxic effects of analytical samples. Here, we report that DT-D has a high dephosphorylation activity: DT-D catalyzes reductive dephosphorylation of a phosphate-containing substrate in the presence of NADH.

Rapid and Sensitive Detection of Aspergillus niger Using a Single-Mediator System Combined with Redox Cycling.

Rapid and sensitive mold detection is becoming increasingly important, especially in indoor environments. Common mold detection methods based on double-mediated electron transfer between an electrode and molds are not highly sensitive and reproducible, although they are rapid and simple. Here, we report a sensitive and reproducible detection method specific to Aspergillus niger ( A.

Washing-Free Displacement Immunosensor for Cortisol in Human Serum Containing Numerous Interfering Species.

Simple and sensitive competitive immunosensors for small molecules are difficult to obtain, especially in serum containing numerous interfering species (ISs) with different concentrations. Herein, we report a washing-free and sensitive (competitive) displacement immunosensor for cortisol in human serum, based on electron mediation of Os(bpy)Cl between an electrode and a redox label [oxygen-insensitive diaphorase (DI)] (i.e.

Nitrosoreductase-Like Nanocatalyst for Ultrasensitive and Stable Biosensing.

Enzyme-like nanocatalytic reactions developed for high signal amplification in biosensors are of limited use because of their low reaction rates and/or unwanted side reactions in aqueous electrolyte solutions containing dissolved O. Herein, we report a nitrosoreductase-like catalytic reaction, employing 4-nitroso-1-naphthol, Pd nanoparticles, and HN-BH, which affords a high reaction rate and minimal side reactions, enabling its use in ultrasensitive electrochemical biosensors. 4-Nitroso-1-naphthol was chosen after five hydroxy-nitro(so)arene compounds were compared in terms of high signal and low background levels.