A photocurrent enhancing photoelectrochemical (PEC) immunosensor was developed for chloramphenicol (CAP) detection based on cation exchange reaction. The efficient split-type PEC immunosensor combined with controlled-release strategy was established using the ZnInS/TiO/TiC MXene (ZIS/T/M) composite as the photoactive material and CuO as the signal response probe. In the presence of target CAP, CuO-labeled CAP antibody (CuO-mAb) was introduced onto the microplate via a competitive-type immunoassay.
View Article and Find Full Text PDFThis study successfully synthesized hydrogels by modifying chitosan with water-soluble and carboxyethyl groups, followed by crosslinking with oxidized carboxymethyl cellulose (OCMC). Structural analyses substantiated the establishment of robust imine linkages between the amino and aldehyde groups, affirming the hydrogel's architecture. Using scanning electron microscopy and texture analysis, it was observed that incorporating water-soluble chitosan significantly increased the hydrogel's porosity and hardness.
View Article and Find Full Text PDFChitosan, as a biomaterial, has increasingly garnered attention. However, its limited solubility in water-only dissolving in certain dilute acidic solutions-substantially restricts its broader application. In this investigation, chitosan underwent a solubilization modification to acquire water solubility, facilitating its dissolution in neutral aqueous mediums.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
July 2024
A colorimetric immunoassay was built for determination of carcinoembryonic antigen (CEA) based on papain-based colorimetric catalytic sensing system through the use of glucose oxidase (GOx). In the presence of GOx, glucose was catalytically oxidized to produce HO. Through the assistance of papain (as a peroxide mimetic enzyme), the signal came from the oxidative color development of 3,3',5,5'-tetramethylbenzidine (TMB, from colorless to blue) catalyzed by the generated HO.
View Article and Find Full Text PDFCarcinoembryonic antigen (CEA), a vital biomarker, plays a significant role in the early diagnosis and prognostic estimation of malignant tumors. In this study, a split-type photoelectrochemical immunoassay for the sensitive quantification of CEA has been successfully developed based on the target-induced formation of a Z-type heterojunction. First, gold nanoparticle-decorated ZnInS (AuNPs/ZnInS) composites were synthesized and used for the fabrication of photoelectrodes.
View Article and Find Full Text PDFThis paper presents the formation of a self-healing hydrogel prepared by carboxyethyl modification of chitosan and crosslinking with oxidized sodium alginate. Concurrently, the incorporation of Ca facilitated the formation of "calcium bridges" through intricate coordination with carboxyl moieties, bolstering the attributes of the hydrogel. Various characterization methods, including scanning electron microscopy, texture analysis, and rheological measurements, demonstrated that the introduction of carboxyethyl groups resulted in a more compact hydrogel network structure and improved the hardness and elasticity.
View Article and Find Full Text PDFObjective: Small extracellular vesicle (sEV)-mediated intercellular communication is increasingly the key for the understanding of venous malformations (VMs). This study aims to clarify the detailed changes of sEVs in VMs.
Subjects And Methods: Fifteen VM patients without treatment history and twelve healthy donors were enrolled in the study.
This work for the first time reports on a simple and rapid colorimetric immunoassay with rapid coordination of ascorbic acid 2-phosphate (AAP) and iron (III) for determination of carcinoembryonic antigen (CEA, used as a model) by using FeO nanoparticle based-chromogenic substrate system. The signal was produced rapidly (1 min) from the coordination of AAP and iron (III) with color development of colorless to brown. TD-DFT calculation methods were employed to simulate the UV-Vis spectra of AAP-Fe and AAP-Fe complexes.
View Article and Find Full Text PDFLead halide perovskites have become a potential candidate as electrochemiluminescence (ECL) emitters owing to their appealing electronic-to-optical merits. It remains extremely challenging, however, to improve stability and enhance charge transfer. Herein, a self-enhanced superstructures was constructed by successively loading N-doped graphene quantum dot (NGQDs) and CsPbBr perovskite nanocrystals (PNCs) onto graphene supported two-dimensional mesoporous SiO nanosheets (2D mSiO-G).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2023
In this work, a split-type dual-mode (colorimetric/photothermal) immunoassay method was designed for point-of-care testing (POCT) detection of mycotoxins (aflatoxin B, AFB as the model analyte) in foodstuffs based on Pt supported on nitrogen-doped carbon amorphous (Pt-CN). The as-synthesized Pt-CN exhibits excellent peroxidase-mimicking activity, which can catalyze the oxidization of 3,3',5,5'-tetramethylbenzidine (TMB) into TMB with sensitive colorimetric readout in the presence of hydrogen peroxide (HO). Moreover, the TMB also serves as a near-infrared (NIR) photothermal agent to convert the colorimetric readout into heat under the irradiation of an 808 nm laser.
View Article and Find Full Text PDFCell Tissue Res
November 2022
Vascular wall resident stem cells (VW-SCs) play a key role in vascular formation and remodeling under both physiological and pathological situations. They not only serve as a reservoir to supply all types of vascular cells needed, but also regulate vascular homeostasis by paracrine effects. Venous malformations (VMs) are common congenital vascular malformations which are just characterized by the deficient quantity and abnormal function of vascular cells.
View Article and Find Full Text PDFNanozymes are a series of elaborately designed nanomaterials that can mimic the catalytic sites of natural enzymes for reactions. Bypassing the tedious design and preparation of nanomaterial, in this work, we report on a novel just-in-time production system of copper hexacyanoferrate nanoparticles (CHNPs), which act as an oxidase-mimicking nanozyme. This system can rapidly produce CHNPs nanozyme on demand by simply mixing Cu(II) with potassium hexacyanoferrate(III) (K[Fe(CN)]).
View Article and Find Full Text PDFObjective: Synovitis is a joint disease that seriously affects patient quality of life, but there are currently no diagnostic markers. The albumin to fibrinogen ratio (AFR) and monocyte to lymphocyte ratio (MLR) are non-invasive and cost-effective markers for various systemic inflammatory diseases. However, these markers have not yet been investigated for synovitis.
View Article and Find Full Text PDFThe relative humidity (RH) determination is crucial in many fields. Based on the phosphorescent properties of room-temperature phosphorescent (RTP) carbon dots, the RTP carbon dots as a probe are expected to be used to rapidly detect relative humidity. In this study, matrix-free room-temperature phosphorescent N-doped carbon dots (N-CDs) were successfully prepared from urea, succinic acid, and acrylamide using a hydrothermal method.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
April 2021
Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial to alleviation of inflammation-related diseases. The objective of this study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague-Dawley (SD) rats with hammer beating served as the in vivo models of acute STI.
View Article and Find Full Text PDF2,4,6-Trinitrophenol (TNP) is widely used in our daily life; however, excessive use of TNP can lead to a large number of diseases. Therefore, it is necessary to find an effective method to detect TNP. Herein, the rapid fluorescence quenching by TNP was developed for the fluorometric determination of TNP in aqueous medium based on the internal filter effect.
View Article and Find Full Text PDFThe aim of this study was to develop a novel colorimetric sensing method based on enzyme-regulated instant generation of Turnbull's blue, serving as a chromogenic agent, for a sensitive immunoassay for the determination of ochratoxin A (OTA). Unlike the traditional enzyme-linked immunosorbent assay (ELISA), the chromogenic reaction reported herein relies on the immediate formation of Turnbull's blue. K[Fe(CN)] rapidly forms a coordinate bond with iron(ii), yielding a blue product.
View Article and Find Full Text PDFThe authors describe a colorimetric immunoassay for the model nalyte aflatoxin B (AFB). It is based on the just-in-time generation of an MnO nanocatalyst. Unlike previously developed immunoassay, the chromogenic reaction relies on the just-in-time formation of an oxidase mimic without the aid of the substrate.
View Article and Find Full Text PDFWe designed a new colorimetric immunoassay for sensitive monitoring of brevetoxin B (BTB) using enzyme-controlled Fenton reaction with a high-resolution 3,3',5,5'-tetramethylbenzidine (TMB)-based visual colored system. Upon addition of hydrogen peroxide (H2O2), the equivalent iron(II) could be first converted into iron(III) and free hydroxyl radical (•OH) via the classical Fenton reaction. Then the as-produced iron(III) and •OH could cause a perceptible change from colorless to blue with the increasing H2O2 concentration in the presence of TMB.
View Article and Find Full Text PDFA new colorimetric immunosensing platform accompanying enzyme cascade amplification strategy was fabricated for quantitative screening of small-molecular mycotoxins (aflatoxin B, AFB used in this case) coupling with enzyme-controlled dissolution of MnO nanoflakes. The visual colored assay was executed by high-efficient MnO-3,3',5,5'-tetramethylbenzidine (TMB) system (blue). In the presence of ascorbic acid, MnO nanoflakes were dissolved into Mn ions, thus resulting in a perceptible color change from blue to colorless.
View Article and Find Full Text PDFPhotoelectrochemical (PEC) detection is an emerging and promising analytical tool. However, its actual application still faces some challenges like potential damage of biomolecules (caused by itself system) and intrinsic low-throughput detection. To solve the problems, herein we design a novel split-type photoelectrochemical immunoassay (STPIA) for ultrasensitive detection of prostate specific antigen (PSA).
View Article and Find Full Text PDFA convenient and feasible photoelectrochemical (PEC) sensing platform based on gold nanoparticles-decorated g-C3N4 nanosheets (AuNP/g-C3N4) was designed for highly sensitive monitoring of T4 polynucleotide kinase (PNK) activity, using DNAzyme-mediated catalytic precipitation amplification. To realize our design, the AuNP/g-C3N4 nanohybrid was initially synthesized through in situ reduction of Au(III) on the g-C3N4 nanosheets, which was utilized for the immobilization of hairpin DNA1 (HP1) on the sensing interface. Thereafter, a target-induced isothermal amplification was automatically carried out on hairpin DNA2 (HP2) in the solution phase through PNK-catalyzed 5'-phosphorylation accompanying formation of numerous trigger DNA fragments, which could induce generation of hemin/G-quadruplex-based DNAzyme on hairpin DNA1.
View Article and Find Full Text PDFA simple colorimetric immunoassay for quantitative monitoring of brevetoxin B on a functionalized magnetic bead by using glucose oxidase (GOx)/antibrevetoxin antibody-labeled gold nanoparticle as the signal transduction tag was developed. The assay was carried out on the basis of GOx-controlled sulfite-to-sulfate chemical conversion with a silver(I)-3,3',5,5'-tetramethylbenzidine [Ag(I)-TMB] system. Initially, the sulfite was used as an inhibitor of Ag(I) to hinder the color development of TMB due to the formation of insoluble silver sulfite.
View Article and Find Full Text PDFA new electrochemical immunosensor was designed for the determination of carcinoembryonic antigen (CEA) with sensitivity enhanced by using nanogold-poly(o-phenylenediamine)-manganese dioxide organic-inorganic hybrid nanostructures (GNPM) as nanotags and peroxidase mimics. Initially, mesoporous poly(o-phenylenediamine)-manganese dioxide (PPD-MnO) hollow microspheres were synthesized by an inorganic/organic interfacial polymerization technique. Then gold nanoparticles were assembled onto the surface of PPD-MnO, which were used for the labelling of the anti-CEA detection antibody (pAb).
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