4,257 results match your criteria lod low

Electrochemical aptasensor for 17β-estradiol using disposable laser scribed graphene electrodes.

Biosens Bioelectron 2021 Apr 28;185:113247. Epub 2021 Apr 28.

Polymer Biointerface Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, PO Box 600, Wellington, New Zealand. Electronic address:

17β-Estradiol (E2), the strongest of the three major physiological estrogens in females, is an important factor in the female reproductive system. The abnormal level of E2 causes health issues, such as weak bones, urinary tract infections and even depression. Here, we present a novel, sensitive and selective, electrochemical aptasensor for detection of 17β-estradiol (E2). Read More

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Electrochemical immunosensor development based on core-shell high-crystalline graphitic carbon nitride@carbon dots and CdZnS/d-TiCT MXene composite for heart-type fatty acid-binding protein detection.

Mikrochim Acta 2021 May 7;188(6):182. Epub 2021 May 7.

Faculty of Health Sciences, Department of Nutrition and Dietetics, Hasan Kalyoncu University, Gaziantep, Turkey.

Acute myocardial infarction (AMI) is a significant health problem owing to its high mortality rate. Heart-type fatty acid-binding protein (h-FABP) is an important biomarker in the diagnosis of AMI. In this work, an electrochemical h-FABP immunosensor was developed based on CdZnS/d-TiCT MXene (MXene: Transition metal carbide or nitride) composite as signal amplificator and core-shell high-crystalline graphitic carbon nitride@carbon dots (hc-g-CN@CDs) as electrochemical sensor platform. Read More

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Thiol functionalized covalent organic framework for highly selective enrichment and detection of mercury by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Analyst 2021 May;146(9):2991-2997

Partner State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, 224 Waterloo Road, Kowloon Tong, Hong Kong, SAR, P. R. China.

A spherical thiol-functionalized covalent organic framework (COF-SH) was designed via a facile thiol-yne click reaction of a alkynyl-terminated COF and pentaerythritol tetra(3-mercaptopropionate). The COF-SH was explored as a new adsorbent for the selective enrichment of Hg2+. The as-prepared COF-SH exhibited a uniform mesoporous structure, a high abundance of binding sites, and good chemical stability, which endow it with great performance for the adsorption of Hg2+ and its corresponding maximum adsorption capacity was up to 617. Read More

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Paper-based analytical device with colorimetric detection for urease activity determination in soils and evaluation of potential inhibitors.

Talanta 2021 Aug 19;230:122301. Epub 2021 Mar 19.

Instituto de Química e Biotecnologia, Universidade Federal de Alagoas, Campus A.C. Simões, 57072-900, Maceió, Alagoas, Brazil. Electronic address:

Urease is an enzyme associated with the degradation of urea, an important nitrogen fertilizer in agriculture. Thus, this current report describes the use of a paper-based analytical device (UrePAD) designed to contain a microzone array for colorimetric determination of urease activity in soils in the absence/presence of potential enzyme inhibitors. The UrePAD can be used at the point-of-need (point-of-care), and it offers advantages such as low cost, simplicity in handling, low sample/reagent volumes, and no use of toxic reagents. Read More

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Development of smart core-shell nanoparticle-based sensors for the point-of-care detection of alpha amylase in diagnostics and forensics.

Biosens Bioelectron 2021 Apr 15;184:113244. Epub 2021 Apr 15.

Nanomedicine Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. Electronic address:

Smart biocompatible materials, responsive to various external stimuli, hold immense potential in the development of biosensors for low-cost diagnostics. The present paper outlines the development of smart enzyme-responsive core-shell nanoparticle-based sensors as low-cost diagnostics for alpha amylase detection. The biocompatible core-shell nanoparticles of 200-250 nm size consisted of a chitosan-tripolyphosphate core formed by ionic gelation coated with a starch-iodine shell. Read More

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Metal-enhanced sensing platform for the highly sensitive detection of C-reactive protein antibody and rhodamine B with applications in cardiovascular diseases and food safety.

Dalton Trans 2021 Apr 30. Epub 2021 Apr 30.

Faculty of Materials Science and Technology, University of Science, Ho Chi Minh City, Viet Nam. and Vietnam National University, Ho Chi Minh City, Viet Nam.

The potential applications of metal-enhanced fluorescence (MEF) devices include biosensors for the detection of trace amounts in biosciences, biotechnology, and pathogens that are relevant to medical diagnostics and food control. In the present study, the silver (Ag) film thickness (56 nm) of an MEF system was calibrated to maximize the depth-to-width ratio (Γ) of the surface plasmon resonance (SPR) active metal from reflectance dip curves. Upon plasmon coupling with thermally evaporated Ag, we demonstrated a 2. Read More

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A lateral flow strip for on-site detection of tobramycin based on dual-functional platinum-decorated gold nanoparticles.

Analyst 2021 Apr 30. Epub 2021 Apr 30.

The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.

A novel lateral flow strip assay has been developed for rapid on-site detection of tobramycin. In this assay, unique dual-functional platinum-decorated gold nanoparticles (Au@Pt NPs) are synthesized by covering conventional gold nanoparticles (AuNPs) with an ultra-thin Pt film. Au@Pt NPs retain the plasmon activity of AuNPs and exhibit ultra-high catalytic activity that the Pt skin can achieve. Read More

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A Phenothiazine-HPQ Based Fluorescent Probe with a Large Stokes Shift for Sensing Biothiols in Living Systems.

Molecules 2021 Apr 17;26(8). Epub 2021 Apr 17.

College of Pharmacy, Qiqihar Medical University, Qiqihar 161006, China.

Due to the redox properties closely related to numerous physiological and pathological processes, biothiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), have received considerable attention in biological science. On account of the important physiological roles of these biothiols, it is of profound significance to develop sensitive and selective detection of biothiols to understand their biological profiles. In this work, we reported an efficient fluorescent probe, , for detecting biothiols in vitro and vivo, based on the phenothiazine-HPQ skeleton, with DNBS (2,4-dinitrobenzenesulfonate) as the response unit. Read More

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Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry.

Biosensors (Basel) 2021 Apr 11;11(4). Epub 2021 Apr 11.

Lash Miller Laboratories, Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.

The determination of protease activity is very important for disease diagnosis, drug development, and quality and safety assurance for dairy products. Therefore, the development of low-cost and sensitive methods for assessing protease activity is crucial. We report two approaches for monitoring protease activity: in a volume and at surface, via colorimetric and acoustic wave-based biosensors operated in the thickness-shear mode (TSM), respectively. Read More

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Recent Advances of Field-Effect Transistor Technology for Infectious Diseases.

Biosensors (Basel) 2021 Apr 2;11(4). Epub 2021 Apr 2.

Biologically Sensors and Actuators (BioSA) Laboratory, Lassonde School of Engineering, York University, Keel Street, Toronto, ON M3J 1P3, Canada.

Field-effect transistor (FET) biosensors have been intensively researched toward label-free biomolecule sensing for different disease screening applications. High sensitivity, incredible miniaturization capability, promising extremely low minimum limit of detection (LoD) at the molecular level, integration with complementary metal oxide semiconductor (CMOS) technology and last but not least label-free operation were amongst the predominant motives for highlighting these sensors in the biosensor community. Although there are various diseases targeted by FET sensors for detection, infectious diseases are still the most demanding sector that needs higher precision in detection and integration for the realization of the diagnosis at the point of care (PoC). Read More

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Saliva Is a Valid Alternative to Nasopharyngeal Swab in Chemiluminescence-Based Assay for Detection of SARS-CoV-2 Antigen.

J Clin Med 2021 Apr 2;10(7). Epub 2021 Apr 2.

Laboratorio di Virologia, Istituto Nazionale per le Malattie Infettive (INMI) Lazzaro Spallanzani IRCCS, 00149 Rome, Italy.

Diagnostic methods based on SARS-CoV-2 antigens detection are a promising alternative to SARS-CoV-2 RNA amplification. We evaluated the automated chemiluminescence-based Lumipulse G SARS-CoV-2 Ag assay on saliva samples, using Simplexa™ COVID-19 Direct assay as a reference test. Analytical performance was established on a pool of healthy donors' saliva samples spiked with the 2019-nCoV/Italy-INMI1 isolate, whereas clinical performance was assessed on fresh saliva specimens collected from hospitalized patients with suspect or confirmed COVID-19 diagnosis. Read More

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Genetic Mapping by Sequencing More Precisely Detects Loci Responsible for Anaerobic Germination Tolerance in Rice.

Plants (Basel) 2021 Apr 6;10(4). Epub 2021 Apr 6.

International Rice Research Institute, DAPO Box 7777, Metro Manila 1301, Philippines.

Direct seeded rice (DSR) is a mainstay for planting rice in the Americas, and it is rapidly becoming more popular in Asia. It is essential to develop rice varieties that are suitable for this type of production system. ASD1, a landrace from India, possesses several traits desirable for direct-seeded fields, including tolerance to anaerobic germination (AG). Read More

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Determination of DDT in honey samples by liquid-liquid extraction with low-temperature purification (LLE-LTP) combined to HPLC-DAD.

Anal Methods 2021 04 12;13(16):1955-1964. Epub 2021 Apr 12.

Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.

Honey is widely consumed worldwide, however, this food can be contaminated by chemical contaminants, such as the insecticide dichlorodiphenyltrichloroethane (DDT). Despite legal restrictions on DDT use, this organochlorine pesticide has been detected in honey collected in several developed and developing countries, representing risks to human health, animals, and the environment due to its high environmental persistence, potential carcinogenicity, and ecotoxicological effects. Thus, the development of an analytical method for DDT monitoring in this matrix is important to ensure food security. Read More

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A facile strategy for synthesis of porous CuO nanospheres and application as nanozymes in colorimetric biosensing.

J Mater Chem B 2021 Apr;9(16):3533-3543

School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.

Due to the unique advantages, developing a rapid, simple and economical synthetic strategy for porous nanomaterials is of great interest. In this work, for the first time, using sodium hypochlorite as a green oxidant, urea was oxidized to CO2 as a carbon source to prepare the fine-particle crosslinked Cu-precursors, which could be further reduced by sodium ascorbate into pure Cu2O nanospheres (NPs) with a porous morphology at room temperature. Interestingly, our study reveals that introduction of an appropriate amount of MgCl2 into the raw materials can tune the pore sizes and surface area, but has no influence on the phase purity of the resulting Cu2O NPs. Read More

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A bi-modal, cellulose-based sensor for fluorometric detection of Fe(III) and antimicrobial studies of its silver-loaded form.

Int J Biol Macromol 2021 Apr 24;183:35-44. Epub 2021 Apr 24.

Department of Chemistry, Faculty of Science, Selcuk University, Konya, Turkey. Electronic address:

The study reports designing of a new, low-cost and environmentally friendly colorimetric and fluorometric sensor by using cellulose-based materials for detection and determination of Fe(III). To make powder cellulose (Cel) and filter paper (PCel) fluorescent, they were modified with hexamethylene diisocyanate (HMDI) and 4-sulfo-1,8-naphthalimide (Nap). Fluorescent Cel-Nap and PCel-Nap materials were used for spectroscopic detection of Fe(III). Read More

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Controllable Graphene Wrinkle for a High-Performance Flexible Pressure Sensor.

ACS Appl Mater Interfaces 2021 May 25;13(17):20448-20458. Epub 2021 Apr 25.

Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, P. R. China.

Flexible pressure sensors have aroused tremendous attention, owing to their broad applications in healthcare, robotics, and prosthetics. So far, it remains a critical challenge to develop low-cost and controllable microstructures for flexible pressure sensors. Herein, a high-sensitivity and low-cost flexible piezoresistive sensor was developed by combining a controllable graphene-nanowalls (GNWs) wrinkle and a polydimethylsiloxane (PDMS) elastomer. Read More

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Fully integrated 3D-printed electrochemical cell with a modified inkjet-printed Ag electrode for voltammetric nitrate analysis.

Anal Chim Acta 2021 May 20;1160:338430. Epub 2021 Mar 20.

Department of Chemistry, Ateneo de Manila University, Quezon City, 1108, Philippines. Electronic address:

To address the need for low-cost analytical tools for on-site aquaculture water quality monitoring, miniaturized electrochemical sensor systems can be readily fabricated using additive manufacturing technologies such as 3D printing and inkjet printing. In this work, we report the design and fabrication of an additively manufactured electrochemical platform featuring a reusable 3D-printed electrochemical cell with integrated reference and counter electrodes, and a replaceable inkjet-printed Ag (IJP-Ag) working electrode. The electrochemical cell was 3D-printed with acrylonitrile butadiene styrene (ABS) filament and features a 3D-printed ABS-carbon counter electrode and a Ag|AgCl|gel-KCl reference electrode with a 3D-printed porous junction directly integrated along the sides of the sample compartment. Read More

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Toehold-mediated ligation-free rolling circle amplification enables sensitive and rapid imaging of messenger RNAs in situ in cells.

Anal Chim Acta 2021 May 29;1160:338463. Epub 2021 Mar 29.

School of Chemistry, Sun Yat-Sen University, 135 Xingang West Road, Guangzhou, 510275, PR China.

In situ analysis of tumor-related messenger RNAs (mRNAs) is significant in identifying cancer cells at the genetic level in the early stage. Rolling circle amplification (RCA)-based methods are primary tools for in situ mRNA assay, however, the necessary ligation reaction not only shows low ligation efficiency, but also greatly prolongs the assay time that increases the risk of cells losing and mRNAs leakage. In this work, we propose a novel toehold-mediated ligation-free RCA (TMLFRCA) on a designed structure-switchable dumbbell-shaped probe (SDP). Read More

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Clinical evaluation of Bladder CARE, a new epigenetic test for bladder cancer detection in urine samples.

Clin Epigenetics 2021 Apr 21;13(1):84. Epub 2021 Apr 21.

Department of Urology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.

Background: Bladder cancer (BC) is the 5th most common cancer in the USA. Non-muscle invasive bladder cancer represents about 70% of all cases and has generally a favorable outcome. However, recurrence rates as high as 60 to 70% and progression rates of 10 to 20% necessitate intensive surveillance with cystoscopy. Read More

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A Simple Determination of Trinitrotoluene (TNT) Based on Fluorescence Quenching of Rhodamine 110 with FRET Mechanism.

J Fluoresc 2021 Apr 20. Epub 2021 Apr 20.

Faculty of Engineering, Department of Chemistry, Istanbul University-Cerrahpasa, Avcilar, 34320, Istanbul, Turkey.

Sensitive and selective detection of nitroaromatic explosives is an important issue in regard to human health, environment, public security and military issues. In this study, a simple and sensitive fluorescence quenching - based assay utilizing Rhodamine 110 as fluorophore probe was developed for the determination of trinitrotoluene (TNT). This sensitive fluorometric method could measure the decrease in fluorescence of Rhodamine 110 (λ = 490 nm, λ = 521 nm) owing to the primary amine groups of Rhodamine 110 (different from other rhodamines) capable of donor-acceptor interaction with TNT. Read More

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Fluorescent and colorimetric dual-mode detection of tetracycline in wastewater based on heteroatoms-doped reduced state carbon dots.

Environ Pollut 2021 Apr 9;283:117109. Epub 2021 Apr 9.

College of Environment and Resources, Xiangtan University, Xiangtan, 411105, Hunan Province, China. Electronic address:

A large amount of tetracycline (TC) persists in water, soil, food, and feed due to the overuse of antibiotics, causing serious environmental problems such as damage to ecosystems and posing risks to human health. Thus, there is an urgent need to find a method to detect TC that is practical, rapid, sensitive, and offers ready visualization of TC levels so that adequate remediation measures can be immediately implemented. Herein, we report a fluorescent and colorimetric dual-mode nanosensor for the detection of TC based on reduced state carbon dots (r-CDs). Read More

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Rapid, ultrasensitive and non-enzyme electrochemiluminescence detection of hydrogen peroxide in food based on the ssDNA/g-CN nanosheets hybrid.

Food Chem 2021 Apr 8;357:129753. Epub 2021 Apr 8.

School of the Environment, Jiangsu University, Zhenjiang 212013, China. Electronic address:

Hydrogen peroxide (HO) is usually used as a fungicide in food, it is carcinogenic, accelerates aging or inducing toxic effects such as cardiovascular disease. Herein, to meet the demand for effective and fast detection of HO in food, a novel non-enzymatic electrochemiluminescence (ECL) sensor based on single-stranded DNA (ssDNA)/g-CN nanosheets (NS) was established. The ssDNA/g-CN NS hybrid was prepared by simple mixing g-CN NS and ssDNA solution together. Read More

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An ultra-sensitive selective fluorescent sensor based on a 3D zinc-tetracarboxylic framework for the detection and enrichment of trace Cu in aqueous media.

Dalton Trans 2021 Apr 25;50(14):4944-4951. Epub 2021 Mar 25.

Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of the Education Ministry, Shanxi University, Taiyuan, Shanxi 030006, P. R. China.

Herein, a novel and fluorescent zinc-organic framework sensor [Zn(μ-Hbptc)(μ-4,4'-bpy)(HO)]·2nHO (1) (Hbptc = 2,3,3',4'-biphenyl tetracarboxylic acid, 4,4'-bpy = 4,4'-bipyridine) is synthesized and characterized, demonstrating its excellent fluorescence performance for Cu detection and the enrichment of Cu in aqueous media. The fluorescence intensity of 1 can be selectively quenched by Cu in a linear range of Cu concentrations of 0-0.7 μM. Read More

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Wireless Self-Powered High-Performance Integrated Nanostructured-Gas-Sensor Network for Future Smart Homes.

ACS Nano 2021 Apr 19;15(4):7659-7667. Epub 2021 Apr 19.

Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.

The accelerated evolution of communication platforms including Internet of Things (IoT) and the fifth generation (5G) wireless communication network makes it possible to build intelligent gas sensor networks for real-time monitoring chemical safety and personal health. However, this application scenario requires a challenging combination of characteristics of gas sensors including small formfactor, low cost, ultralow power consumption, superior sensitivity, and high intelligence. Herein, self-powered integrated nanostructured-gas-sensor (SINGOR) systems and a wirelessly connected SINGOR network are demonstrated here. Read More

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Investigating the effect of 6-mercaptohexanol on the performance of a biosensor based on nanosurface energy transfer between gold nanoparticles and quantum dots.

Anal Methods 2021 Apr 19. Epub 2021 Apr 19.

College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.

Nanosurface energy transfer (NSET)-based sensors have been widely developed using various pairs of nanomaterials including gold nanoparticles (AuNPs) and quantum dots (QDs). However, a low signal to background ratio is one of the most important problems that researchers are continually trying to solve. Herein, we present a 6-mercaptohexanol (MCH) modified MCH/DNA-Au-QD sensor for the detection of nucleic acids and MUC1. Read More

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Continuous twin screw granulation: Impact of microcrystalline cellulose batch-to-batch variability during granulation and drying - A QbD approach.

Int J Pharm X 2021 Dec 19;3:100077. Epub 2021 Mar 19.

Laboratory of Pharmaceutical Technology, Department of Pharmaceutics, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium.

Despite significant advances in the research domain of continuous twin screw granulation, limited information is currently available on the impact of raw material properties, especially considering batch-to-batch variability. The importance of raw material variability and subsequent mitigation of the impact of this variability on the manufacturing process and drug product was recently stressed in the Draft Guidance for Industry on Quality Considerations for Continuous Manufacturing by the U.S. Read More

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December 2021

Naked-Eye Detection of Hepatitis B Surface Antigen Using Gold Nanoparticles Aggregation and Catalase-Functionalized Polystyrene Nanospheres.

ACS Omega 2021 Apr 30;6(14):9828-9833. Epub 2021 Mar 30.

Key Laboratory of Optoelectronic Technology & Systems (Chongqing University), Ministry of Education, Chongqing 400044, China.

Developing rapid, efficient, highly sensitive, simple, stable, and low-cost virus marker detection products that are appropriate for basic facilities is of great importance in the early diagnosis and treatment of viruses. Naked-eye detection methods are especially important when medical testing facilities are limited. Polystyrene nanospheres (PSs) with catalytic and specific recognition functions were successfully developed by simultaneously modifying catalase and goat anti-hepatitis B surface antibodies on nanospheres. Read More

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Single Molecule Assay for Ultrasensitive Detection of Cathepsin B in Human Blood.

ACS Omega 2021 Apr 31;6(14):9609-9616. Epub 2021 Mar 31.

Brain Trauma Neuroprotection Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States.

Cathepsin B (catB) is a lysosomal cysteine protease expressed in several cells and organs, where it plays a role in protein degradation and turnover. Extracellular, secreted catB has utility as a biomarker for a host of pathological or physiological states, including a myriad of cancers or neurological diseases and injuries. Analytical or diagnostic assessment may be limited by biological sample volume availability. Read More

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Altered toxicological endpoints in humans from common quaternary ammonium compound disinfectant exposure.

Toxicol Rep 2021 9;8:646-656. Epub 2021 Mar 9.

Department of Biomedical Science, E. Via College of Osteopathic Medicine - Virginia, Blacksburg, VA, 24060, USA.

Humans are frequently exposed to Quaternary Ammonium Compounds (QACs). QACs are ubiquitously used in medical settings, restaurants, and homes as cleaners and disinfectants. Despite their prevalence, nothing is known about the health effects associated with chronic low-level exposure. Read More

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A time-resolved fluorescence lateral flow immunoassay for rapid and quantitative serodiagnosis of Brucella infection in humans.

J Pharm Biomed Anal 2021 Apr 15;200:114071. Epub 2021 Apr 15.

Department of Transfusion Medicine, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, 510515, China. Electronic address:

Brucellosis is a worldwide infectious zoonotic disease, posing severe threats to human health and social-economic development. By comparing with time-consuming, low sensitive and non-quantitative conventional serological methods, herein, protein G (prG) coupled with europium nanospheres (EuNPs) (detection probe) and highly purified Brucella lipopolysaccharide (LPS) (capture antigen) were used to develop a novel time-resolved fluorescence lateral flow immunoassay (TF-LFIA) for detecting anti-Brucella IgG antibody in human plasmas. The entire testing took 15 min. Read More

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