Enhanced nanobody-driven bioluminescent immunoassay for rapid parathion detection using engineered split-nanoluciferase.

In this work, with parathion, a typical forbidden organophosphate pesticide as target drug, an enhanced nanobody-driven bioluminescent immunoassay based on the engineered split-nanoluciferase (NanoLuc) was proposed. Concretely, through labeling 11S and β10, two split-NanoLuc units onto the anti-parathion nanobody (Nb) VHH9 and the artificial antigen H1 coupled with carrier protein ovalbumin (H1-OVA) respectively, an NanoLuc Binary Technology (NanoBiT) system was firstly developed in the form of homogeneous immunoassay, in which the luminescence signal was produced by the reassembled NanoLuc after the combination of the 11S-fused VHH9 and β10-labeled H1-OVA. Subsequently, in order to enhance the signal-to-noise (S/N) ratio, a novel strategy of splitting 11S into two smaller subunits Δ11S and β9 was adopted so then an NanoLuc Ternary Technology (NanoTeT) system based on tri-part components of β9-fused VHH9, β10-labeled H1-OVA and Δ11S was successfully established.

The Simultaneous Determination of Chlorpyrifos-Ethyl and -Methyl with a New Format of Fluorescence-Based Immunochromatographic Assay.

The improper and excessive use in agriculture of chlorpyrifos-methyl (CPSM) and chlorpyrifos-ethyl (CPSE) may affect the health of human beings. Herein, a fluorescence-based immunochromatographic assay (FICA) was developed for the simultaneous determination of CPSM and CPSE. A monoclonal antibody (mAb) with equal recognition of CPSM and CPSE was generated by the careful designing of haptens and screening of hybridoma cells.

Nanobodies for Accurate Recognition of Iso-tenuazonic Acid and Development of Sensitive Immunoassay for Contaminant Detection in Foods.

The accurate analysis of chemical isomers plays an important role in the study of their different toxic effects and targeted detection of pollutant isomers in foods. The mycotoxins tenuazonic acid (TeA) and iso-tenuazonic acid (ITeA) are two isomer mycotoxins with the lack of single analysis methods due to the similar structures. Antibody-based immunoassays exhibit high sensitivity and superior application in isomer-specific determination.

Ultrasensitive and rapid colorimetric detection of paraquat via a high specific VHH nanobody.

Rapid and quantitative detection of paraquat is crucial because of its high toxicity. Here, we developed an ultrasensitive time-resolved fluorescence immunochromatographic assay (TRFICA) strip based on our synthesized variable domain of heavy chain antibody (VHH, also called Nanobody) for paraquat detection. Briefly, the specific immunogen selected from six designed antigens was employed to immunize alpaca, and a high-efficiency capacity of 1.

Prussian blue nanoparticles-enabled sensitive and accurate ratiometric fluorescence immunoassay for histamine.

Herein, a nanozyme-mediated ratiometric fluorescence immunoassay for histamine (HA) has been developed. Prussian blue nanoparticles (PBNPs) with outstanding peroxidase-like activity were labelled with goat anti-mouse IgG via a facile electrostatic adsorption to yield the nanozyme-antibody conjugate which acted as a bridge to link the ratiometric fluorescence readout with HA concentration. As substrate, o-phenylenediamine (OPD) was oxidized into 2,3-diaminophenazine (oxOPD) by HO under the catalysis of PBNPs, producing a novel emission at 570 nm and quenching the fluorescence of carbon dots (CDs) at 450 nm simultaneously.

Citrulline Accumulation Mechanism of and in Soy Sauce and the Effects of Phenolic Compound on Citrulline Accumulation.

Citrulline is one of the major precursors of ethyl carbamate in soy sauce, and the accumulation of citrulline is attributed to the metabolism of arginine by bacteria with the arginine deiminase (ADI) pathway. However, key strains and factors affecting citrulline accumulation are not yet clear. In this study, two key strains of and were isolated from soy sauce , and the regularity of citrulline formation was studied.

Noni ( L.) Fruit Polysaccharides Regulated IBD Mice Via Targeting Gut Microbiota: Association of JNK/ERK/NF-κB Signaling Pathways.

Inflammatory bowel disease (IBD) is a disease characterized by intestinal inflammation with immune dysregulation and intestinal microecological imbalance. In a dextran sulfate sodium salt (DSS)-induced IBD mouse model, noni ( L.) fruit polysaccharides (NFP) with homogalacturonan and rhamnogalacturonan-I domain decreased the concentration of serum LPS, TNF-α, and IL-17 by 84, 42, and 65%, respectively.

Enhanced Non-Toxic Immunodetection of Mycotoxin Tenuazonic Acid Based on Ferritin-Displayed Anti-Idiotypic Nanobody-Nanoluciferase Multimers.

The non-toxic immunoassay for mycotoxins is being paid more attention due to its advantages of higher safety and cost savings by using anti-idiotype antibodies to substitute toxins. In this study, with tenuazonic acid (TeA), a kind of highly toxic mycotoxin as the target, an enhanced non-toxic immunoassay was developed based on the ferritin-displayed anti-idiotypic nanobody-nanoluciferase multimers. First, three specific β-type anti-idiotype nanobodies (AId-Nbs) bearing the internal image of TeA mycotoxin were selected from an immune phage display library.

The Most Active Oxidase-Mimicking Mn O Nanozyme for Biosensor Signal Generation.

Oxidase-mimicking nanozymes are more desirable than peroxidase-mimicking ones since H O can be omitted. However, only a few nanomaterials are known for oxidase-like activities. In this work, we compared the activity of Mn O , Mn O and MnO and found that Mn O had the highest oxidase activity.

Inhibition of ethyl carbamate accumulation in soy sauce by adding quercetin and ornithine during thermal process.

Ethyl carbamate (EC), a genotoxic and carcinogenic compound in soy sauce accumulated during thermal processes, has raised public health concern for its multipoint potential carcinogenic risk to human. In this work, based on the analysis of EC accumulation during thermal processes of soy sauce, ornithine and quercetin were added before thermal processes to reduce EC accumulation. A reduction rate of 23.

Visual upconversion nanoparticle-based immunochromatographic assay for the semi-quantitative detection of sibutramine.

Immunochromatographic assay (ICA) has been used widely for the onsite monitoring of illegal additives due to its simplicity, speed, and low cost. However, a scanner is commonly required for ICA to achieve quantitative results. In this work, we developed a visual semi-quantitative ICA for sibutramine, a banned additive in diet foods, without the need for a scanner for measurement.

Fluorescent enzyme-linked immunoassay based on silane-doped carbon dots for sensitive detection of microcystin-LR in water and crucian samples.

In this work, a fluorescent nanoparticles labeling-free fluorescence enzyme-linked immunoassay (FELISA) has been established for the ultrasensitive detection of microcystin-LR (MC-LR) in water and fish samples. Polyclonal antibody against MC-LR was labeled with horseradish peroxidase (HRP) and used as signal probe for binding with analyte in sample or for coating antigen. After washing of the unbound antibody, the substrate system (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS)/HO) was added.

Dislocation Engineered PtPdMo Alloy With Enhanced Antioxidant Activity for Intestinal Injury.

Radiotherapy is the mainstay for abdomen and pelvis cancers treatment. However, high energy ray would inflict gastrointestinal (GI) system and adversely disrupt the treatment. The anti-oxidative agents provide a potential route for protecting body from radiation-induced injuries.

The Constipation-Relieving Property of d-Tagatose by Modulating the Composition of Gut Microbiota.

d-tagatose, a monosaccharide as well as a dietary supplement, has been reported as having a wide range of applicability in the food industry, however, the prebiotic activity, anticonstipation effects, and related mechanisms are still unclear. In this study, using the loperamide-induced constipation Kunming mice as the animal model, the effects of d-tagatose for the prevention of constipation were evaluated by gastrointestinal transit experiment and defecation experiment. Furthermore, the underlying mechanism was clarified by evaluating the change of the biochemical indicators and analyzing 16S rRNA amplicon of gut microbiota among the different mice groups.

A rapid and simple fluorescence enzyme-linked immunosorbent assay for tetrabromobisphenol A in soil samples based on a bifunctional fusion protein.

Tetrabromobisphenol A (TBBPA) is the largest brominated flame retardant which can be released to environment and cause long-term hazard. In this work, we developed a rapid and highly sensitive fluorescence enzyme-linked immunosorbent assay (FELISA) for monitoring of TBBPA in soil samples. TBBPA specific nanobody derived from camelid was fused with alkaline phosphatase to obtain the bi-functional fusion protein, which enable the specific binding of TBBPA and the generation of detection signal simultaneously.

High affinity antibody based on a rationally designed hapten and development of a chemiluminescence enzyme immunoassay for quantification of Alternariol in fruit Juice, maize and flour.

Alternariol (AOH), a secondary metabolites of the genus Alternaria, is a genotoxic mycotoxin. Because the previous "Mannich antigen" for AOH readily underwent unstable induction, a new AOH hapten was designed for inducing a high-quality antibody against AOH using a conjugate of the AOH carboxymethyl derivative with a carrier protein as the immunogen. A competitive indirect chemiluminescence enzyme immunoassay (ciCLEIA) for AOH was optimized and showed good sensitivity (limit of detection 0.

Ultrasensitive immunosensor for acrylamide based on chitosan/SnO-SiC hollow sphere nanochains/gold nanomaterial as signal amplification.

An electrochemical immunosensor for ultrasensitive detection of acrylamide (AA) in water and food samples was developed. SnO-SiC hollow sphere nanochains with high surface area and gold nanoparticles with good electroconductivity were fabricated onto the surface of a glassy carbon electrode pre-coated with chitosan. The coating antigen (AA-4-mercaptophenylacetic acid-ovalbumin conjugate, AA-4-MPA-OVA) was immobilized on the electrode.

Naturally-Derived PHA-L Protein Nanoparticle as a Radioprotector Through Activation of Toll-Like Receptor 5.

High energy ray in medical diagnosis and therapy can benefit to patients, but can also cause the significant damages to biomolecules such as DNA, as well as free radical generation, inevitably leading to numerous side effects. Small molecular radioprotectors provide an effective route to preserve the healthy tissue and whole body from ionizing radiation, but always have a short circulation time in body. Inorganic nanoparticles show major protection effect but their heavy metal components considerably jeopardize translational promise due to suboptimal biocompatibility.

A full-automated magnetic particle-based chemiluminescence immunoassay for rapid detection of cortisol in milk.

A sensitive full-automated micromagnetic particles (MMPs) based competitive chemiluminescent immunoassay (CLIA) was developed to detect cortisol in milk. Polyclonal antibody (pAb) with good specificity against cortisol was produced. The antigen (cortisol-OVA) was labeled with acridinium ester (cortisol-OVA-AE) as signal tracer.

Production of Antigen-Binding Fragment against ,-Diethyl Organophosphorus Pesticides and Molecular Dynamics Simulations of Antibody Recognition.

Immunoassay for pesticides is an emerging analytical method since it is rapid, efficient, sensitive, and inexpensive. In this study, a recombinant antigen-binding fragment (Fab) against a broad set of ,-diethyl organophosphorus pesticides (DOPs) was produced and characterized. The κ chain and Fd fragment were amplified via PCR and inserted into the vector pComb3XSS and the soluble Fab on phagemid pComb3XSS was induced by isopropyl -d-thiogalactoside in TOP 10F’.

Preparation and cellular protection against oxidation of Konjac oligosaccharides obtained by combination of γ-irradiation and enzymatic hydrolysis.

Konjac glucomannan (KGM) is an important source for preparation of Konjac oligo-glucomannan (KOG), but high molecular weight and viscosity in KGM inhibited its full degradation into KOG. In this study, KOG with a degree of polymerization between 2 and 9 was obtained by combining γ-irradiation and enzymatic hydrolysis in high yield. We investigated the protective effect of KOG against HO - induced oxidative damage in vitro, using human hepatic cell line (LO2) as a cell model.

Physicochemical Properties of Bovine Serum Albumin-Glucose and Bovine Serum Albumin-Mannose Conjugates Prepared by Pulsed Electric Fields Treatment.

The pulsed electric fields (PEF) treatment is a novel method for obtaining glycated proteins by way of a Maillard reaction between proteins and polysaccharides but its effect on the preparation of protein-monosaccharide conjugate has not been explored. This study aimed to prepare bovine serum albumin (BSA)-glucose and BSA-mannose conjugates using PEF in pH 10.0 at an intensity of 10 or 20 kV/cm, frequency of 1 kHz, pulse width of 20 μs and 73.

Nutritional Composition and Antioxidant Properties of the Fruits of a Chinese Wild Passiflora foetida.

The aim of this work was to evaluate the main nutrients and their antioxidant properties of a Chinese wild edible fruit, , collected from the ecoregion of Hainan province, China. The analytical results revealed that fruits were rich in amino acids (1097 mg/100 g in total), minerals (595.75 mg/100 g in total), and unsaturated fatty acids (74.

Fluorescence enhancement of gold nanoclusters Zn doping for biomedical applications.

Gold nanoclusters (NCs) have been widely used in bioimaging and cancer therapy due to their unique electronic structures and tunable luminescence. However, their weak fluorescence prevents potential biomedical application, and thus it is necessary to develop an effective route to enhance the fluorescence of gold NCs. In this work, we report the fluorescence enhancement of ultrasmall GSH-protected Au NCs by Zn atom doping.