Integration of DNA-Decorated Hapten in Emergency Immunoassays for Antibody and Small-Molecule Detection: A Review.

DNA-decorated hapten (DDH)-based immunoassays have emerged, demonstrating supreme advantages in sensing applications because of their excellent sensitivity, specificity, and reliability. DDH combines both a recognition element (hapten) and a signal transduction element (DNA portion) with its highly programmable DNA structure enabling the trigger of signal transduction following a recognition event, thereby introducing a novel signal transduction mechanism to immunoassays. In this review, we provide a critical overview of recent research in the DDH-based immunoassays, which are designed to detect specific small molecules and antibodies.

ZIF-derived Co nanoparticles embedded into N-doped carbon nanotube composites for highly efficient electrochemical detection of nitrofurantoin in food.

Designing efficient and sensitive methods for the detection of nitrofurantoin (NFT) residues is of great importance for food safety and environmental protection. Herein, a composite with cobalt nanoparticles encapsulated in nitrogen-doped carbon nanotube (N/Co@CNTs@CC-II) was synthesized by in-situ growth and sublimation-gas phase transformation strategy and used to establish an ultrasensitive electrochemical sensor for NFT determination. The N/Co@CNTs@CC-II sensor exhibits uniform N doping, fine hollow structure, and abundant active metal sites, which lays a solid foundation for the ultra-sensitive detection of NFT.

Sn/MoC@NC hollow nanospheres as Schottky catalyst for highly sensitive electrochemical detection of methyl parathion.

Developing electrode materials with excellent electrocatalytic properties for detecting pesticide residues plays a vital role in the safety of agricultural products and environmental applications. Herein, we designed a new electrochemical sensor on the basis of N-doped carbon hollow nanospheres modified with Sn/MoC Schottky junction (Sn/MoC@NC) for methyl parathion (MP) detection. The Sn/MoC@NC was prepared by self-assembled polymerization-anchoring strategy and high-temperature carbonization design.

Immunochromatographic Assay based on Sc-TCPP 3D MOF for the rapid detection of imidacloprid in food samples.

In this work, a highly sensitive immunochromatographic test strip (ITS) based on Scandium-Tetrakis (4-carboxyphenyl) porphyrin (TCPP) metal-organic framework nanocubes (ScTMNs) was developed for ultrasensitive and facile visual determination of imidacloprid (IDP). TCPP as the porphyrin-based planar ligand and Sc as the metal center were applied to form the ScTMNs via coordination chelation. Giving the credit to its excellent optical characteristics, strong affinity with monoclonal antibodies, and favorable biocompatibility, the ScTMNs was selected as a signal tag.

Simple high-temperature annealing affords commercial carbon cloth with enhanced electrochemical performance for highly sensitive detection of imidacloprid.

Imidacloprid (IDP) residue in modern agricultural production seriously endangers human health and environmental safety. The establishment of a rapid and efficient method for the detection of IDP residue can effectively prevent its harm to human health. Herein, we demonstrate the carbon cloth (CC) prepared by a high-temperature annealing strategy possesses enhanced electrochemical performance, which could be directly used in electrochemical IDP sensing.

Sodium caseinate decorating on shellac nanoparticles as a stabilizer for the encapsulation of quercetin.

To protect quercetin and address some of the barriers about shellac as a delivery carrier, we investigated the effects of sodium caseinate surface decoration on the formation, stability, and physiochemical properties of shellac nanoparticles (SNPs) for the first time. Herein, 0.3% caseinate was selected to prepare the quercetin-loaded shellac/sodium caseinate complex nanoparticles (SQCNPs), ensuring stable formation of nanoparticles and preventing irreversible aggregation of SNPs in acid.

Hybrid structures of cobalt-molybdenum bimetallic oxide embedded in flower-like molybdenum disulfide for sensitive detection of the antibiotic drug nitrofurantoin.

Excessive residues of nitrofurantoin (NFT) can cause serious contamination of water bodies and food, and potential harm to ecosystems and food safety. Given that, rapid and efficient detection of NFT in real samples is of particular importance. MoS is a promising electrochemical material for this application.

Golf-shaped BiSe microparticles based-immunochromatographic strip for ultrasensitive detection of Acetamiprid.

Rapid and sensitive detection of pesticide is of significance to the field of food safety and human health, but it is still challenging due to interferents from complex food matrices. Herein, a superb golf-shaped BiSe microparticles-based immunochromatographic strip (BS MPs-ICS) was constructed for ultrasensitive detection of acetamiprid (ATM). The novel immune signal tag demonstrated outstanding luminance, excellent biocompatibility, and high affinity with ATM (affinity constant was 3.

Dual-Modal Immunochromatographic Test for Sensitive Detection of Zearalenone in Food Samples Based On Biosynthetic -Mediated Polymer Dot Nanocomposites.

The rapid detection of toxins is of great significance to food security and human health. In this work, a dual-modality immunochromatographic test (DICT) mediated by (SA)-biosynthesized polymer dots (SABPDs) was constructed for sensitive monitoring of zearalenone (ZEN) in agro products. The SABPDs as potent microorganism nanoscaffolds with excellent solubility, brightness, and stability were ingeniously fabricated employing hydroquinone and SA as precursors in the Schiff base reaction and a self-assembly technique.

"Lighting-up" methylene blue-embedded zirconium based organic framework triggered by Al for advancing the sensitivity of E. coli O157:H7 analysis in dual-signal lateral flow immunochromatographic assay.

The sensitive detection of foodborne pathogens is of great significance for ensuring food safety and quality. Herein, on the basis of methylene blue-embedded zirconium based organic framework (UIO@MB) as the remarkable capture carrier and signal indicator, with the Al-assisted the fluorescent signal response, we developed a label-free and dual-signal lateral flow immunochromatographic assay (LDLFIA) for sensitive detection of Escherichia coli (E. coli) O157:H7.

Rose petals-like Bi semimetal embedded on the zeolitic imidazolate frameworks based-immunochromatographic strip to sensitively detect acetamiprid.

Ultrasensitive and facile detection of Acetamiprid (ACE) is of exceptional significance to assess the environmental and biological pollution. In this study, an advanced Bi semimetal/Zeolitic imidazolate frameworks hybrid material-based immunochromatographic strip (Bi/ZIF HM-ICS) sensor was developed for the sensitive detection of ACE. The novel Bi/ZIF HM was prepared through one-pot hydrothermal reduction of Bi nanoparticles on ZIF, which was selected as a signal tag taking advantages of its excellent color intensity, strong affinity with monoclonal antibodies (mAbs), and favorable biocompatibility.

Integrating electrochemical sensor based on MoO/CoO heterostructure for highly sensitive sensing of nitrite in sausages and water.

Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, CoO nanoflowers coupled with ultrafine MoO nanoparticles (MoO/CoO) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO/CoO/CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO and CoO caused by the heterostructure of MoO/CoO.

Multifunctional bacteria-derived tags for advancing immunoassay analytical performance with dual-channel switching and antibodies bioactivity sustaining.

Constructing multifunctional immunochromatographic assays (ICA) carriers with multiple signals and retaining bioactivity of monoclonal antibodies (mAbs) are conducive to the sensitive and accurate point-of-care testing (POCT). To fulfill this pressing need, a microorganism-based microsphere mediated dual-modal ICA (DICA) was developed for sensitive and reliable detection of zearalenone (ZEN). As the key to the biosensor, a superb biotag with an intact coccus morphology was designed based on Staphylococcus aureus biosynthesized quantum dots incorporating Ru(bpy) (SAQDsRu), in which SA offered a specific recognition capacity for Fc region of mAbs, QDs endowed a naked-eye discernible colorimetric signal on the SA, and robust fluorescence signal that remedied for the insufficient brightness of QDs was derived from Ru(bpy).

Well-orientation strategy for direct binding of antibodies: Development of the immunochromatographic test using the antigen modified FeO nanoprobes for sensitive detection of aflatoxin B.

One of the major concerns in the application of nanocarriers in biosensing is the impair of the recognition molecules bioactivity loaded on their surfaces due to harsh and laborious cross-linking and random orientation, resulting in unsatisfactory sensitivity. Herein, we proposed a novel immunochromatographic test strip (FNS-ag-DICTS) by taking advantage of the antigen (ag) modified FeO nanostructures (FNSs) as new signal tags and goat anti-mouse IgG labeling on the detection line instead of ag, which was used for sensitive detection of aflatoxin B (AFB). The fabricated FNS-ag can orientate the Fab region of monoclonal antibodies (mAbs), waiving the intrinsic limitations of traditional nanomaterials labeled mAbs.

Immunochromatographic Assay Based on Polydopamine-Decorated Iridium Oxide Nanoparticles for the Rapid Detection of Salbutamol in Food Samples.

Salbutamol (SAL), a β-2 adrenoreceptor agonist, is an unpopular addition to livestock and poultry, causing several side effects to human health. Thus, it is very important to develop a simple and rapid analytical method to screen SAL in the field of food safety. Here, we present an immunochromatographic assay (ICA) method for sensitively detecting SAL with polydopamine-decorated iridium oxide nanoparticles (IrO@PDA NPs) as a signal tag.

Diverse Dyes-Embedded as Potential Biocarriers for Enhancing Sensitivity in Biosensing.

Nanomaterials-based immunochromatographic assays (ICAs) have gained great commercial success in real-life point-of-care testing (POCT). Exploring novel carriers of ICAs with improved signaling and sustained activity favors the development of sensitive POCT. Herein a potent signal biotag, colored (SA), was created for ICA carriers through a mild self-assembly strategy, providing high luminance and abundant specific binding sites for immobilization of monoclonal antibodies (mAbs).

Dual-Emission Zr-MOF-Based Composite Material as a Fluorescence Turn-On Sensor for the Ultrasensitive Detection of Al.

In this work, a novel zirconium-based metal-organic framework (MOF) composite material, UiO-(OH)@RhB, has been solvothermally prepared with zirconyl chloride octahydrate, 2,5-dihydroxyterephthalic acid, and rhodamine B (RhB) for ratiometric fluorescence sensing of Al ions in an aqueous medium. The luminescence measurement results showed that, at the single excitation wavelength of 420 nm, the fluorescence intensity of the ligand at 500 nm increased significantly in the case of Al, while that of RhB at 583 nm changed slightly, together with an apparent color change. Under optimal conditions, UiO-(OH)@RhB exhibited an extraordinary sensitivity (10 nM), good selectivity, and a fast response (2 min) for Al.

An innovative prussian blue nanocubes decomposition-assisted signal amplification strategy suitable for competitive lateral flow immunoassay to sensitively detect aflatoxin B.

A prussian blue nanocubes decomposition-assisted signal amplification strategy for competitive lateral flow immunoassay (PBNCD-SALFIA) was innovatively proposed to analyze aflatoxin B (AFB) in foodstuffs. The signal was amplified on account of the PBNCs can degrade and fade under alkaline condition, which could weak the color of the test- and control-lines, thereby improving the sensitivity of the sensor. The strategy was technically-simple, just using NaOH as an amplifier can realize signal amplification in the competition assay.

Gold nanoparticles-functionalized three-dimensional flower-like manganese dioxide: A high-sensitivity thermal analysis immunochromatographic sensor.

A sensitive photothermal immunochromatographic test strip (PITS) for the detection of deoxynivalenol (DON) was developed using flower-like gold nanoparticle-deposited manganese dioxide nanocarrier (FMD-G NC) labeled antibodies (Abs) as the photothermal-sensing probe. FMD was used as a template to deposit small gold nanoparticles (GNPs) to synthesize FMD-G NC with large specific surface area and significant photothermal conversion property. The FMD-G-Ab probe was competitively captured by DON target and antigen coated on test line (T-line), forming colorimetric signals under naked eyes and photothermal signals under an 808 nm laser.

Polydopamine coated zirconium metal-organic frameworks-based immunochromatographic assay for highly sensitive detection of deoxynivalenol.

Conventional immunochromatographic assays (ICAs) based on gold nanoparticles (GNPs) suffer from the disadvantage of low sensitivity. In this work, a highly sensitive ICA based on polydopamine coated zirconium metal-organic frameworks labeled antibodies (ZrPA-Ab) as a novel probe was developed for visual determination of deoxynivalenol (DON). The ZrPA was synthesized via an oxidative self-polymerized assembly (OPMA) strategy using porphyrin functionalized zirconium metal-organic frameworks (Zr-MOFs, MOF-525) and polydopamine (PDA).

Chitosan-based bifunctional composite aerogel combining absorption and phototherapy for bacteria elimination.

The bacterial infection is one of the most common but critical problems in the wound healing process due to the general antibiotic resistance of bacteria. Hence it is increasingly necessary and urgent to develop an advanced and efficient sterilization strategy. Herein, a chitosan-based aerogel embedded amino-functionalized molybdenum disulfide nanosheets (abbreviated to CS/NMNSs) was successfully constructed through amino modification and physical assembly.

Metal-polydopamine framework based lateral flow assay for high sensitive detection of tetracycline in food samples.

Gold nanoparticles (AuNPs)-based lateral flow assay (LFA) enables a rapid detection of tetracycline (TET) in food samples but suffers from low sensitivity. Herein, metal-polydopamine framework (MPF), as a label, was employed to load monoclonal antibodies (mAbs) directly as the probe in LFA for highly sensitive sensing of TET. Combining zeolitic imidazolate framework (ZIF-67) and polydopamine (PDA), a stable MPF with large size, well water-dispersible, excellent affinity and optical properties was prepared through a versatile layer-by-layer assembly (LLA) strategy.

FeO@CuS-based immunochromatographic test strips and their application to label-free and dual-readout detection of Escherichia coli O157:H7 in food.

Herein, a label-free and dual-readout immunochromatographic test strip (ITS) for the sensitive detection of Escherichia coli (E. coli) O157:H7 by taking advantages of the strong capture ability of FeO@CuS nanostructures (NSs) towards bacteria and their ultrahigh photothermal effects (PTEs) was reported. Especially, without the customarily antibody (Ab)-labeled probe, FeO@CuS NSs could be adsorbed onto the surfaces of bacteria to form FeO@CuS-bacteria conjugates and then trapped by immobilized Abs on the test line (T-line), forming a characteristic yellow band.