Automatic detection of multi-antibiotic residues simultaneously in aquatic products by visual protein microarray chips.

A 96-well microplate-based protein microarray chip which can simultaneously detect three different families of antibiotics using a multiplexed approach has been developed for the first time. All steps in the microarray chip can be completed through an automated biochip analyzer, enabling high throughput analysis of 96 samples within 60 min according to the set program. The microarray chip can be visually evaluated by the color depth of array points, and can also be quantified through a scanner.

High-Performance Suspension Bead Sensor Based on Optical Tweezers and Immuno-Rolling Circle Amplification.

In recent years, optical tweezers have become an effective bioassay tool due to their unique advantages, especially in combination with suspension beads, which can be applied to develop a high-performance analysis platform capable of high-quality imaging and stable signal output. However, the optical tweezer-assisted bead analysis is still at the early stage, and further development of different favorable methods is in need. Herein, we have first developed the optical tweezer-assisted immuno-rolling circle amplification (immuno-RCA) on beads for protein detection.

Simultaneous detection of five mycotoxins in traditional Chinese medicines (TCMs) by visual protein microarray.

The pollution of mycotoxins to crops such as traditional Chinese medicines (TCMs) is an established problem throughout the world. Thus, mycotoxin determination in TCMs during production and processing is significantly necessary, which means rapid, sensitive and accurate analytical methods are needed. In this work, a new method of visual protein microarray based on a 96-well microtiter plate was proposed.

Machine learning-assisted matrix-assisted laser desorption/ionization time-of-flight mass spectrometry toward rapid classification of milk products.

This study established a method for rapid classification of milk products by combining MALDI-TOF MS analysis with machine learning techniques. The analysis of 2 different types of milk products was used as an example. To select key variables as potential markers, integrated machine learning strategies based on 6 feature selection techniques combined with support vector machine (SVM) classifier were implemented to screen the informative features and classify the milk samples.

A versatile dilution-treatment-detection microfluidic chip platform for rapid In vitro lung cancer drug combination sensitivity evaluation.

Combination drug therapy represents an effective strategy for treating certain drug-resistant and intractable cancer cases. However, determining the optimal combination of drugs and dosages is challenging due to clonal diversity in patients' tumors and the lack of rapid drug sensitivity evaluation methods. Microfluidic technology offers promising solutions to this issue.

A label-free aptasensing method for detecting SARS-CoV-2 virus antigen by using dumbbell probe-mediated circle-to-circle amplification.

Controlling the spread of pathogen requires an efficient and accurate diagnosis. Compared with nucleic acid and antibody detection, antigen assays are more convenient to meet clinical diagnostic needs. However, antigen detection is often difficult to achieve high sensitivity in a limited time.

A novel label-free capillary electrophoresis LED-induced fluorescence platform based on catalytic hairpin assembly for sensitive detection of multiple circulating tumor DNA.

Circulating tumor DNA (ctDNA) is a highly promising biomarker for the early diagnosis and treatment of gastric cancer (GC). However, there is still a lack of effective and practical ctDNA detection methods. In this work, a simple and economical capillary non-gel sieving electrophoresis-LED induced fluorescence detection (NGCE-LEDIF) platform coupled with catalytic hairpin assembly (CHA) as the signal amplification strategy is proposed for quantitative detection of PIK3CA E542K and TP53 (two types of ctDNA associated with GC).

In-Depth Serum Proteomics Reveals the Trajectory of Hallmarks of Cancer in Hepatitis B Virus-Related Liver Diseases.

Hepatocellular carcinoma (HCC) is a prevalent cancer in China, with chronic hepatitis B (CHB) and liver cirrhosis (LC) being high-risk factors for developing HCC. Here, we determined the serum proteomes (762 proteins) of 125 healthy controls and Hepatitis B virus-infected CHB, LC, and HCC patients and constructed the first cancerous trajectory of liver diseases. The results not only reveal that the majority of altered biological processes were involved in the hallmarks of cancer (inflammation, metastasis, metabolism, vasculature, and coagulation) but also identify potential therapeutic targets in cancerous pathways (i.

An ultrasensitive fluorescence aptasensor for SARS-CoV-2 antigen based on hyperbranched rolling circle amplification.

Sensitive and accurate diagnosis of SARS-CoV-2 infection at early stages can help to attenuate the effects of the COVID-19. Compared to RNA and antibodies detection, direct detection of viral antigens could reflect infectivity more appropriately. However, it is still a great challenge to construct a convenient, accurate and sensitive biosensor with a suitable molecular recognition element for SARS-CoV-2 antigens.

Web hybrid chain reaction enhanced fluorescent magnetic bead array for digital nucleic acid detection.

The detection of biomarkers at low concentrations is important in clinical diagnostic analyses and has attracted continuous research. In this work, absolute quantification of hepatitis B virus (HBV) DNA was achieved using magnetic beads with isothermal, enzyme-free DNA nanostructure for fluorescence amplification. Firstly, the DNA-functionalized bead captured the target nucleic acid in the form of sandwich hybridization, and the individual target lighted up the entire bead by isothermal web hybridization chain reaction (wHCR).

Highly-sensitive and simple fluorescent aptasensor for 17 b-estradiol detection coupled with HCR-HRP structure.

As an important kind of environmental endocrine disruptors, 17 β -Estradiol (E2) plays a major role in affecting the growth of human including sexual characters, pregnancy system, etc. In the modern society, with the threat of abuse in breeding, it is imperative to design sensitive methods for detecting low concentration of E2 in environment. In this work, we constructed a highly sensitive and simple fluorescent aptasenor for detecting E2 via amplification of hybridization chain reaction (HCR) and horseradish peroxidase (HRP).

Fully Automatic Multi-Class Multi-Residue Analysis of Veterinary Drugs Simultaneously in an Integrated Chip-MS Platform.

Microfluidic chip analysis has great potential advantages such as high integration, fast speed analysis, and automatic operation and is widely used not only in biological fields but also in many other analytical areas such as agriculture and food safety. Herein, a fully automatic multi-class multi-residue analysis of veterinary drugs simultaneously in an integrated chip-mass spectrometry (chip-MS) platform was developed. The developed microfluidic chip platform integrated three modules including the extraction and filtration module, "pass-through" clean-up module, and online evaporation module.

A Cascaded DNA Circuit in Bead Arrays for Quantitative Single-Cell MicroRNA Analysis.

Single-cell microRNA (miRNA) analysis helps people understand the causes of diseases and formulate new disease treatment strategies. However, miRNA from a single cell is usually very rare and requires signal amplification for accurate quantification. Here, to amplify the signal, we constructed the cascaded DNA circuits consisting of catalytic hairpin assembly and hybrid chain reaction into the bead array platform, on which the uniformly distributed beads were adopted for miRNA quantification.

MoS-Assisted LDI Mass Spectrometry for the Detection of Small Molecules and Quantitative Analysis of Sulfonamides in Serum.

A two-dimensional MoS nanosheet was prepared by a chemical exfoliation method and served as an excellent matrix for the detection of small molecules by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In comparison with organic matrices (CHCA, 3-AQ) and a graphene matrix, we found that a MoS matrix showed better performance in analysis of amino acids, peptides, fatty acids, and sulfonamides. A systematic comparison of the MoS matrix with both ion modes showed that mass spectra produced in negative ion mode featured a corresponding single deprotonated ion, which was rather different from the complex multiple alkali metal addition peaks present in positive ion mode.

A fluorescent microarray platform based on catalytic hairpin assembly for MicroRNAs detection.

The DNA microarray has distinctive advantages of high-throughput and less complicated operations, but tends to have a relatively low sensitivity. Catalytic hairpin assembly (CHA) is one of the most promising enzyme-free, isothermal DNA circuit for high efficient signal amplification. Here, a microarray-based catalytic hairpin assembly (mi-CHA) biosensing method has been developed to detect various miRNAs in a single test simultaneously.

Accomplishment of one-step specific PCR and evaluated SELEX process by a dual-microfluidic amplified system.

One of the main obstacles for systematic evolution of ligands by exponential enrichment (SELEX) failure is the generation of a non-specific product, as selection-inherent amplification procedures tend to form by-products, which prevents the enrichment of target-binding aptamers. Herein, we reported a dual-microfluidic amplified system (dual-MAS) based on the real-time polymerase chain reaction (PCR) detection chip and the large volume PCR chip for one-step specific PCR and for evaluating the SELEX process. First, it is a simple method to accomplish analytical PCR and amplification PCR in one step, and the optimal number of cycles for generating the specific PCR product is the cycles when the slope of the linear amplification period of the real-time PCR curve begins to decrease.

Screening aptamers for serine β-lactamase-expressing bacteria with Precision-SELEX.

Klebsiella pneumoniae carbapenemase 2 (KPC-2) is a serine β-lactamase that can hydrolyze almost all β-lactam antibiotics. The drug resistant problem of bacteria expressing carbapenemases is currently a global problem, therefore, rapid and specific detection of pathogenic bacteria is urgent. In order to obtain an aptamer that can specifically recognize bacteria expressing KPC-2, we have established a method called Precision-SELEX.

On-line multi-residue analysis of fluoroquinolones and amantadine based on an integrated microfluidic chip coupled to triple quadrupole mass spectrometry.

An on-line multi-residue qualitative and quantitative analysis method for fluoroquinolones and amantadine using an integrated microfluidic chip was developed prior to directly coupling to triple quadrupole mass spectrometry (QQQ-MS). Six parallel channels consisting of sample filtration units and micro solid phase extraction (micro-SPE) columns were present in the specifically designed microfluidic device. Firstly, the impurities in the sample solution were trapped by the micropillars in the filtration units.

A novel method combining aptamer-AgNPs based microfluidic biochip with bright field imaging for detection of KPC-2-expressing bacteria.

The β-lactam drugs resistance poses a serious threat to human health throughout the world. Klebsiella pneumoniae carbapenemase 2 (KPC-2) is a carbapenemase that produced in bacteria can hydrolyze carbapenems, which typically considered as the antibiotics of last resort. Therefore, there is an urgent need to quickly and accurately detect whether bacteria express KPC-2.

The discovery of lactoferrin dual aptamers through surface plasmon resonance imaging combined with a bioinformation analysis.

An analytical method for screening aptamers for different recognition sites in lactoferrin (Lac) molecules has been developed based on Surface Plasmon Resonance imaging (SPRi), combined with the cluster classification calculation of a quasi-aptamer library strategy and molecular docking simulation analysis. Using the software simulation, a homology analysis was performed on the selected quasi-aptamer sequences, which could be divided into 8 different families. Based on the principle of biomolecular recognition, a label-free, high-throughput dual immune site screening method was established, in which the nucleic acid aptamers of recognizing ability for lactoferrin molecules were fixed onto the surface of the SPRi sensor chip and could bind to the lactoferrin molecules.

COVID-19 diagnostic testing: Technology perspective.

The corona virus disease 2019 (COVID-19) is a highly contagious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). More than 18 million people were infected with a total of 0.7 million deaths in ∼188 countries.

Highly Integrated Microfluidic Chip Coupled to Mass Spectrometry for Online Analysis of Residual Quinolones in Milk.

In this work, a highly integrated microfluidic chip with multifunction coupled to mass spectrometry (MS) was developed for online analysis of seven different regulated quinolones (QNs) in milk samples. Procedures of sample extraction, immunoaffinity enrichment, magnetic separation, and online elution were performed simultaneously on the specifically designed device. Based on the specificity of antibodies, direct (electrospray ionization) ESI-MS at full scan mode without liquid chromatography (LC) separation and further tandem mass spectrometry (MS/MS) analysis was developed for the identification of target QNs.

Enzyme-free fluorescence microarray for determination of hepatitis B virus DNA based on silver nanoparticle aggregates-assisted signal amplification.

In this study, we designed a fluorescence enhancement strategy based on silver nanoparticle (AgNP) aggregates for the detection of hepatitis B virus DNA sequences. AgNPs were functioned with recognition probes (Cy3-probe) and hybrid probes (Oligomer-A and Oligomer-B). The presence of target DNA mediated the formation of sandwich complexes between the immobilized capture probes and the functionalized AgNPs, which was followed by hybridization-induced formation of AgNP aggregates.