A novel smartphone-mediated ratiometric fluorescence imprinting sensor based on boric acid-functionalized Eu-MOF for the detection of horseradish peroxidase.

Horseradish peroxidase (HRP) was used as a model glycoprotein, and a molecularly imprinted ratiometric fluorescence sensor based on a smartphone (NEB@MIP) was constructed using the sol-gel method for the fluorescence and visual detection of HRP. The sensor consisted of boronic acid-functionalized metal-organic frameworks (Eu-MOF-B(OH)) and nitrogen-doped carbon dots (N-CDs). The Eu-MOF-B(OH) surface can not only load abundant N-CDs but also covalently bind with HRP through its boronic acid groups.

Magnetism-Functionalized Lanthanide MOF-on-MOF with Plasmonic Differential Signal Amplification for Ultrasensitive Fluorescence Immunoassays.

The successful application of fluorescence immunoassays for clinical diagnosis requires stable photoluminescent materials and highly efficient signal amplification strategies. In this work, the magnetism-functionalized lanthanide MOF-on-MOF (FeO@SiO@MOF-on-MOF) was synthesized through intermolecular (van der Waals) interaction-assisted growth and further homogeneous epitaxial growth, which significantly improved the fluorescence performances and uncovered the underlying mechanism. The quantum chemical theory calculation and experimental studies revealed that the introduced magnetic FeO@SiO not only endowed magnetic separation capability but also promoted fluorescence performances, which increased the energy transfer of the intersystem crossing process and suppressed the luminescence of ligands and aggregation-induced quenching.

A ratiometric fluorescence imprinted sensor based on N-CDs and metal-organic frameworks for visual smart detection of malathion.

Sensitive and rapid detection of pesticide residues in food is essential for human safety. A ratiometric imprinted fluorescence sensor N-CDs@Eu-MOF@MIP (BR@MIP) was constructed to sensitively detect malathion (Mal). Europium-based metal organic frameworks (Eu-MOF) were used as supporters to improve the sensitivity of the BR@MIP.

A signal-off photoelectrochemical sandwich-type immunosensor based on WO/TiO Z-scheme heterojunction.

A sandwich "signal-off" type photoelectrochemical (PEC) immunosensor was fabricated based on a composite heterojunction of tungsten oxide/titanium oxide microspheres (WO/TiO) acting as signal amplification platform and carbon microspheres loaded by gold nanoparticles (Cs@Au NPs) utilized as the label for detecting antibody. WO/TiO had excellent photoelectric performance, and the results of Mott-Schottky plots, open-circuit voltage, and electron spin resonance spectroscopy indicated that it belonged to the Z-scheme heterojunction transfer mechanism of photogenerated carriers. To achieve the sensitization of PEC immunosensor, Cs@Au NP-labeled immunocomplex can effectively reduce the photocurrent signal.

Novel dual-emission fluorescence imprinted sensor based on Mg, N-CDs and metal-organic frameworks for rapid and smart detection of 2, 4, 6-trinitrophenol.

Rapid and real-time detection of 2, 4, 6-trinitrophenol (TNP) is of great importance for the living environment and human health. Herein, we constructed an innovative ratiometric fluorescence imprinted sensor with fast response and high selectivity based on magnesium and nitrogen co-doped carbon dots (Mg, N-CDs) and chromium telluride quantum dots (r-CdTe) self-assembled in zirconium-based metal organic frameworks (UiO-66) combined with imprinted polymers for the detection of TNP. In the protocol, the introduction of UiO-66 with large specific surface area and porosity using as carrier material significantly enhanced the mass transfer rate, which improved the sensitivity of the Mg, N-CDs/r-CdTe@UiO-66@MIP (LHU@MIP).

A Novel SPR Immunosensor Based on Dual Signal Amplification Strategy for Detection of SARS-CoV-2 Nucleocapsid Protein.

Since the global outbreak of coronavirus disease 2019 (COVID-19), it has spread rapidly around the world. The nucleocapsid (N) protein is one of the most abundant SARS-CoV-2 proteins. Therefore, a sensitive and effective detection method for SARS-CoV-2 N protein is the focus of research.

A novel smartphone-integrated binary-emission molecularly imprinted fluorescence sensor embedded with MIL-101(Cr) for sensitive and real-time detection of protein.

Aiming for precise, real-time, and on-site analysis of proteins, an innovative binary-emission fluorescence imprinted polymer was designed by sol-gel method after mixing MIL-101(Cr), green CdTe (g-CdTe) and red CdTe (r-CdTe) for detection of protein. In this proposal, MIL-101(Cr), as a favorable supporter, provided high surface area and porosity for imprinting sites, which ameliorated the transfer rate and the sensitivity of the nanosensor. And g-CdTe and r-CdTe were served as signal transduction for dual-emission response.

CdTe QDs-sensitized TiO nanocomposite for magnetic-assisted photoelectrochemical immunoassay of SARS-CoV-2 nucleocapsid protein.

A sensitive, reliable, and cost-effective detection for SARS-CoV-2 was urgently needed due to the rapid spread of COVID-19. Here, a "signal-on" magnetic-assisted PEC immunosensor was constructed for the quantitative detection of SARS-CoV-2 nucleocapsid (N) protein based on Z-scheme heterojunction. FeO@SiO@Au was used to connect the capture antibody to act as a capture probe (FeO@SiO@Au/Ab).

Trimetallic Au@Pd@Pt nanozyme-enhanced lateral flow immunoassay for the detection of SARS-CoV-2 nucleocapsid protein.

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seriously threatened global public health. Establishing a rapid and sensitive diagnostic test for early detection of the SARS-CoV-2 nucleocapsid protein is urgently required to defend against the pandemic. Herein, an enhanced lateral flow immunoassay (LFIA) was fabricated by trimetallic Au@Pd@Pt core-shell nanozymes for detection of the SARS-CoV-2 nucleocapsid protein.

A Highly Sensitive Fluorescence and Screen-Printed Electrodes-Electrochemiluminescence Immunosensor for Ricin Detection Based on CdSe/ZnS QDs with Dual Signal.

A sensitive dual-readout immunosensor for fluorescence and electrochemiluminescence (ECL) detection of ricin was established, which was combined with a streptavidin-biotin signal amplification system. CdSe/ZnS quantum dots with fine fluorescence and ECL properties were used as the dual-signal function probes of the sandwich immunocomplex. Under the optimum experimental conditions, the dual signal intensity increased significantly with the rise in ricin concentration.

Magnetic/fluorescent dual-modal lateral flow immunoassay based on multifunctional nanobeads for rapid and accurate SARS-CoV-2 nucleocapsid protein detection.

The SARS-CoV-2 pandemic has posed a huge challenge to rapid and accurate diagnosis of SARS-CoV-2 in the early stage of infection. In this work, we developed a novel magnetic/fluorescent dual-modal lateral flow immunoassay (LFIA) based on multifunctional nanobeads for rapid and accurate determination of SARS-CoV-2 nucleocapsid protein (NP). The multifunctional nanobeads were fabricated by using polyethyleneimine (PEI) as a mediate shell to combine superparamagnetic FeO core with dual quantum dot shells (MagDQD).

A photoelectrochemical immunosensor based on magnetic all-solid-state Z-scheme heterojunction for SARS-CoV-2 nucleocapsid protein detection.

Rapid, convenient and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is urgently needed to timely diagnosis of coronavirus pandemic (COVID-19) and control of the epidemic. In this study, a signal-off photoelectrochemical (PEC) immunosensor was constructed for SARS-CoV-2 nucleocapsid (N) protein detection based on a magnetic all-solid-state Z-scheme heterojunction (FeO@SiO@TiO@CdS/Au, FSTCA). Integrating the advantages of magnetic materials and all-solid-state Z-scheme heterostructures, FSTCA was implemented to ligate the capture antibody to form magnetic capture probe (FSTCA/Ab).

A photoelectrochemical immunosensor based on Z-scheme CdS composite heterojunction for aflatoxin B1.

Aflatoxin B1 (AFB1) is a highly toxic fungal contaminant widely found in agricultural products. It causes serious harm to human health and the environment. Thus, a fast and sensitive detection approach is urgently needed to prevent AFB1-contaminated products from entering the market effectively.

Construction of g-CN/Au/NH-UiO-66 Z-scheme heterojunction for label-free photoelectrochemical recognition of D-penicillamine.

The wide clinical application of d-penicillamine (D-PA) makes it inevitably accumulates in the environment, seriously threatening human health and the ecological environment. To better supervisory control D-PA, a highly sensitive and reliable photoelectrochemical (PEC) sensor based on gold nanoparticles (Au NPs) loaded on graphitic carbon nitride sheet and hexagonal NH-UiO-66 composite (g-CN/Au/NH-UiO-66) was synthesized. Tactfully using the strong bonding between D-PA and Au NPs and the effective carrier separation of Z-scheme heterojunction, the designed g-CN/Au/NH-UiO-66 PEC sensor without an extra recognition unit exhibited a selective and sensitive photocurrent to D-PA.

Efficient detection for Nitrofurazone based on novel AgS QDs/g-CN fluorescent probe.

In the paper, a novel fluorescent probe based on AgS QDs/g-CN composite was synthesized by loading AgS quantum dots (AgS QDs) on the surface of g-CN through in-situ synthesis method and developed to detect Nitrofurazone (NFZ) sensitively. The results showed that the linear detection range of AgS QDs/g-CN to NFZ was 0-30 μM, with a low detection limit of 0.054 μM.

Enhanced degradation of chloramphenicol through peroxymonosulfate and visible light over Z-scheme Photocatalysts: Synergetic performance and mechanism insights.

Effective removal of antibiotics in the environment can be a demanding issue concerning the ecosystem and human health. Photocatalysis and peroxymonosulfate (PMS) oxidation have become important methods to effectively remove stubborn pollutants. In this work, by integrating these two technologies, an efficient system for degrading chloramphenicol (CAP) in water was proposed.

Label-free photoelectrochemical immunosensor for aflatoxin B1 detection based on the Z-scheme heterojunction of g-CN/Au/WO.

Aflatoxin B1 (AFB1) is the most toxic mycotoxin, is widely found in foods and animal feeds, and can pose a serious threat to our lives. A label-free photoelectrochemical (PEC) immunosensor was fabricated for the sensitive detection of AFB1. A Z-scheme heterojunction of gold nanoparticles (Au NPs) loaded on graphitic carbon nitride sheet and tungsten trioxide sphere composite (g-CN/Au/WO) acted as the highly sensitive platform.

Electrochemical Immunosensors for Sensitive Detection of Neuron-Specific Enolase Based on Small-Size Trimetallic Au@Pd^Pt Nanocubes Functionalized on Ultrathin MnO Nanosheets as Signal Labels.

Medically, neuron-specific enolase (NSE) as a specific tumor marker has become an important indicator to diagnose small-cell lung carcinoma. In this study, a sandwich-type electrochemical immunosensor was designed to determine NSE sensitively. Au nanoparticle (Au NP)-embedded zinc-based metal-organic frameworks (Au@MOFs) were prepared as the substrate materials to modify the electrode and immobilize the primary antibody (Ab).

A ratiometric fluorescent sensor based on g-CNQDs@Zn-MOF for the sensitive detection of riboflavin via FRET.

A novel ratiometric fluorescent sensor based on Förster resonance energy transfer (FRET) platform was designed for riboflavin (RF) detection. The graphitic carbon nitrides quantum dots - Zn-MOF composite (g-CNQDs@Zn-MOF) was used as the fluorescent probe. In the FRET system, g-CNQDs@Zn-MOF and RF acted as donor and acceptor, respectively.

Fluorescent MoS QDs based on IFE for turn-off determination of FOX-7 in real water samples.

A novel method for turn-off sensing 1,1-diamino-2,2-dinitroethylene (FOX-7) in aqueous medium was first proposed based on the inner filter effect (IFE) of FOX-7 on the fluorescence of molybdenum disulfide quantum dots (MoS QDs). Water-soluble MoS QDs as the fluorophore were prepared by the simple hydrothermal method. The morphology, structure, composition and optical properties of the prepared MoS QDs were characterized by Transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-vis absorption and photoluminescence spectra.

The preparation of hollow AgPt@Pt core-shell nanoparticles loaded on polypyrrole nanosheet modified electrode and its application in immunosensor.

The designed synthesis of efficient materials can significantly enhance the performance of electrochemical immunoassay in the detection of diseases, pesticide residues and environmental pollutants. The hollow AgPt@Pt core-shell nanoparticles (AgPt@Pt HNs) have exhibited high catalytic efficiency to the hydrogen peroxide (HO) reduction for its high mass activity from their hollow structure. Their limitation of instability can be overcome by loading on polypyrrole nanosheet (PPy NS).

Electrochemical immunosensor based on MoS NFs/Au@AgPt YNCs as signal amplification label for sensitive detection of CEA.

Medically, the dynamic change of carcinoembryonic antigen (CEA) concentration has been an important indicator for monitoring and diagnosing tumors. The sensitive and early detection of CEA plays a momentous role in the prevention and diagnosis of cancer and the evaluation of treatment efficiency. In this work, a sensitive sandwich-type electrochemical immunosensor was fabricated for the quantitative detection of CEA.

A sandwich-type electrochemical immunosensor based on RhPt NDs/NH-GS and Au NPs/PPy NS for quantitative detection hepatitis B surface antigen.

In this work, a sandwich-type electrochemical immunosensor was fabricated to quantitatively detect hepatitis B surface antigen (HBsAg). The immunosensor was based on Rh core and Pt shell nanodendrites loaded onto amino group functionalized graphene nanosheet (RhPt NDs/NH-GS) as label and gold nanoparticles loaded onto polypyrrole nanosheet (Au NPs/PPy NS) as platform. RhPt NDs with abundant catalytic active sites because of the branched core-shell structure, RhPt NDs/NH-GS as the label displayed high catalytic activity, amplifying the current signal of the immunosensor.

A sandwich-type amperometric immunosensor fabricated by Au@Pd NDs/Fe-CS/PPy NTs and Au NPs/NH-GS to detect CEA sensitively via two detection methods.

The quantitative detection of carcinoembryonic antigen (CEA) is significant to assess tumor status and therapeutic efficiency. In this study, a sandwich-type amperometric immunosensor for CEA detection sensitively was fabricated by novel signal amplification system. The signal amplification system was formed by gold nanoparticles loaded on amino functionalized graphene sheet (Au NPs/NH-GS) and gold@palladium nanodendrites loaded on ferrous-chitosan functionalized polypyrrole nanotubes (Au@Pd NDs/Fe-CS/PPy NTs).