Nanopore-assisted ELISA for ultrasensitive, portable, and on-site detection of ricin.

Effective detection technologies in food safety with the merits of portable and on-site detection potential are always in pressing demand. Herein, we developed a nanopore-assisted Enzyme-linked immunosorbent assay (NELISA) platform, which innovatively introduced hairpin DNA (HP DNA) probes as reaction substrates. This innovation of substrates effectively avoided the inherent limitations of colorimetric signals (i.

A nanopore-based label-free CRISPR/Cas12a system for portable and ultrasensitive detection of zearalenone.

Background: Food safety has become a serious global concern. Therefore, there is a need for effective detection technologies in this field. Currently, the development of effective on-site detection techniques is extremely important for food safety.

Nanopore-Based Biomimetic ssDNA Reporters for Multiplexed Detection of Meat Adulteration.

Meat adulteration detection is crucial for ensuring food safety, protecting consumer rights, and maintaining market integrity. However, the current methods face challenges in achieving multiplexed detection through efficient signal conversion and output. This study introduces a nanopore-based approach for the simultaneous detection of multiple meat adulteration.

A Clickase-Mediated Immunoassay Based on Nanopore and Bionic Signal Labels for Ultrasensitive, Portable, and On-Site Detection of Ricin.

It is of particular importance to develop an effective method that possesses several merits simultaneously of rapid, ultrasensitive, portable, and on-site detection potential for food safety detection. Herein, we propose a clickase-mediated immunoassay based on nanopore and bionic signal labels for the detection of ricin. The introduction of Cu/Cys clickase and nanopore simultaneously effectively addressed the inherent limitations of natural enzymes and colorimetric signal output, respectively.

Recent advances in nanopore-based analysis for carbohydrates and glycoconjugates.

Saccharides are not only the basic constituents and nutrients of living organisms, but also participate in various life activities, and play important roles in cell recognition, immune regulation, development, cancer, The analysis of carbohydrates and glycoconjugates is a necessary means to study their transformations and physiological roles in living organisms. Existing detection techniques can hardly meet the requirements for the analysis of carbohydrates and glycoconjugates in complex matrices as they are expensive, involve complex derivatization, and are time-consuming. Nanopore sensing technology, which is amplification-free and label-free, and is a high-throughput process, provides a new solution for the identification and sequencing of carbohydrates and glycoconjugates.

Recent advances of nanopore technique in single cell analysis.

Single cells and their dynamic behavior are closely related to biological research. Monitoring their dynamic behavior is of great significance for disease prevention. How to achieve rapid and non-destructive monitoring of single cells is a major issue that needs to be solved urgently.

Emerging Nanoparticles in Food: Sources, Application, and Safety.

Nanoparticles (NPs) are small-sized, with high surface activity and antibacterial and antioxidant properties. As a result, some NPs are used as functional ingredients in food additives, food packaging materials, nutrient delivery, nanopesticides, animal feeds, and fertilizers to improve the bioavailability, quality, and performance complement or upgrade. However, the widespread use of NPs in the industry increases the exposure risk of NPs to humans due to their migration from the environment to food.

Facile synthesis of boric acid-functionalized magnetic covalent organic frameworks and application to magnetic solid-phase extraction of trace endocrine disrupting compounds from meat samples.

A facile approach was proposed for the preparation of boric acid-functionalized core-shell structured magnetic covalent organic framework (COF) nanocomposites through employing the FeO nanoparticles as magnetic core, boric acid-functionalized COFs as the shell via sequential post-synthetic modification (denoted as FeO@COF@BA). The synthesized nanocomposites showed large specific surface area, high magnetic responsiveness, and desirable chemical and thermal stability. Combined with HPLC-MS/MS, the as-prepared FeO@COF@BA composite was applied as a sorbent for magnetic solid-phase extraction (MSPE) of endocrine disrupting compounds (EDCs) from meat samples.

Artificial clickase-triggered fluorescence "turn on" based on a click bio-conjugation strategy for the immunoassay of food allergenic protein.

Herein, based on an artificial clickase-catalyzed bio-conjugation strategy, we established a sensitive fluorescent clickase-linked immunosorbent assay (FCLISA) platform using an oligonucleotide-molecular beacon (Oligo-MB) hairpin structure as a fluorescence switch for detection of food allergenic protein. Firstly, a highly stable Cu(I)-containing nanocube was prepared for usage as an artificial clickase, which could catalyze the bio-conjugation of two short oligonucleotides (i.e.

High-efficiency enzyme-free catalyzed hairpin assembly-mediated homogeneous SERS and naked-eyes dual-mode assay for ultrasensitive and portable detection of mycotoxin.

We developed an aptamer recognition-trigged enzyme-free catalyzed hairpin assembly (CHA) assisted signal amplification homogeneous naked-eyes and surface-enhanced Raman scattering (SERS) dual-mode sensor for highly sensitive and portable detection of Aflatoxin B (AFB) in food samples. The recognition of AFB by aptamer induced the generation of HP1-AFB complexes, which hybridized with Ag-labeled hairpin DNA (HP2) and released Ag, subsequently initiating the enzyme-free CHA reaction by a designed helper DNA (HP3) to form double-stranded DNA (HP2-HP3) and accompanied by the release of HP1-AFB complexes. The released HP1-AFB complexes were recognized by HP2 and HP3 again to trigger cascade recycling amplification and resulted in the generation of a larger number of free Ag and dsDNA.

Low background interference SERS aptasensor for highly sensitive multiplex mycotoxin detection based on polystyrene microspheres-mediated controlled release of Raman reporters.

Mycotoxin contamination is a serious global issue in food safety. The accurate detection of mycotoxins in complex samples, particularly via a portable detection system that realizes multi-analyte detection, remains a great challenge. Here, a polystyrene (PS)-mediated surface-enhanced Raman scattering (SERS) aptasensor was designed for ultrasensitive and simultaneous detection of multiple mycotoxins in food samples.

An aptamer-assisted biological nanopore biosensor for ultra-sensitive detection of ochratoxin A with a portable single-molecule measuring instrument.

Biological nanopore-based single-molecule detection technology has shown ultrahigh sensitivity to various target analyte. But the detection scope of interesting targets is limited due to the lack of effective signal conversion strategies. In addition, conventional nanopore detection instruments are cumbersome, resulting nanopore detection can only be performed in laboratory.

Recent advances of sensing strategies for the detection of β-glucuronidase activity.

β-Glucuronidase (β-GLU), a kind of hydrolase, is widely distributed in mammalian tissues, body fluids, and microbiota. Abnormal changes of β-GLU activity are often correlated with the occurrence of diseases and deterioration of water quality. Therefore, detection of β-GLU activity is of great significance in biomedicine and environmental health such as cancer diagnosis and water monitoring.

Recent Progress on Single-Molecule Detection Technologies for Food Safety.

Rapid and sensitive detection technologies for food contaminants play vital roles in food safety. Due to the complexity of the food matrix and the trace amount distribution, traditional methods often suffer from unsatisfying accuracy, sensitivity, or specificity. In past decades, single-molecule detection (SMD) has emerged as a way to realize the rapid and ultrasensitive measurement with low sample consumption, showing a great potential in food contaminants detection.

Bio-inspired Nanoenzyme Synthesis and Its Application in A Portable Immunoassay for Food Allergy Proteins.

Nanozymes as a cost-effective and robust enzyme mimic have attracted widespread attention in the development of novel analytical methods. Herein, a new nanozyme-enhanced surface-enhanced Raman scattering (SERS) immunoassay platform was successfully developed using a peroxidase-mimicking nanozyme to replace the natural enzymes as a catalytic label of the enzyme-linked immunosorbent assay for the detection of allergy proteins. In this platform, the peroxidase-mimicking nanozymes as a catalytic label could catalyze the oxidation of the Raman-inactive reporter [i.

Crowding-Induced DNA Translocation through a Protein Nanopore.

A crowded cellular environment is highly associated with many significant biological processes. However, the effect of molecular crowding on the translocation behavior of DNA through a pore has not been explored. Here, we use nanopore single-molecule analytical technique to quantify the thermodynamics and kinetics of DNA transport under heterogeneous cosolute PEGs.

Hybridization chain reaction (HCR) for amplifying nanopore signals.

Circulating tumor DNA (ctDNA) in the blood is an important biomarker for noninvasive diagnosis, assessment, prediction and treatment of cancer. However, sensing performance of solid nanopore is limited by the fast kinetics of small DNA targets and unmatched dimensions. Here, we combines hybridization chain reaction (HCR) with nanopore detection to translate the presence of a small DNA target to characteristic nanopore signals of a long nicked DNA polymer.

Simultaneous High-Resolution Detection of Bioenergetic Molecules using Biomimetic-Receptor Nanopore.

A novel artificial receptor, heptakis-[6-deoxy-6-(2-hydroxy-3-trimethylammonion-propyl) amino]-beta-cyclomaltoheptaose, with similar functions of mitochondrial ADP/ATP carrier protein, was synthesized and harbored in the engineered α-HL (M113R) nanopore, forming a single-molecule biosensor for sensing bioenergetic molecules and their transformations. The strategy significantly elevates both selectivity and signal-to-noise, which enables simultaneous recognition and detection of ATP, ADP, and AMP by real-time single-molecule measurement.

Single-molecule transformation and analysis of glutathione oxidized and reduced in nanopore.

The determination of glutathione reduced (GSH) or oxidized (GSSG) in bulk solution has been reported previously. However, it is critically important to set up a simple and label-free method to recognize GSSG and GSH selectively and dynamically, especially at a single-molecule level. Here we report a novel nanopore method to recognize GSSG based on a newly synthesized per-6-quaternary ammonium-β-cyclodextrin (p-QABCD), which is used as both the molecular adaptor of protein nanopore and the recognizing element of GSSG.