Specific and Quantitative Detection of Albumin in Biological Fluids by Tetrazolate-Functionalized Water-Soluble AIEgens

2019 ◽  
Vol 11 (33) ◽  
pp. 29619-29629 ◽  
Author(s):  
Yujie Tu ◽  
Yeqing Yu ◽  
Zhibiao Zhou ◽  
Sheng Xie ◽  
Bicheng Yao ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Water Soluble ◽  
Quantitative Detection

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals Streamlined circular proximity ligation assay provides high stringency and compatibility with low-affinity antibodies

2018 ◽  
Vol 115 (5) ◽  
pp. E925-E933 ◽  
Author(s):  
Roxana Jalili ◽  
Joe Horecka ◽  
James R. Swartz ◽  
Ronald W. Davis ◽  
Henrik H. J. Persson
Keyword(s):  
Limit Of Detection ◽  
Biological Fluids ◽  
Protein Detection ◽  
Ease Of Use ◽  
Proximity Ligation Assay ◽  
Quantitative Detection ◽  
High Signal ◽  
Affinity Reagents ◽  
Proximity Ligation ◽  
Assay Format

Proximity ligation assay (PLA) is a powerful tool for quantitative detection of protein biomarkers in biological fluids and tissues. Here, we present the circular proximity ligation assay (c-PLA), a highly specific protein detection method that outperforms traditional PLA in stringency, ease of use, and compatibility with low-affinity reagents. In c-PLA, two proximity probes bind to an analyte, providing a scaffolding that positions two free oligonucleotides such that they can be ligated into a circular DNA molecule. This assay format stabilizes antigen proximity probe complexes and enhances stringency by reducing the probability of random background ligation events. Circle formation also increases selectivity, since the uncircularized DNA can be removed enzymatically. We compare this method with traditional PLA on several biomarkers and show that the higher stringency for c-PLA improves reproducibility and enhances sensitivity in both buffer and human plasma. The limit of detection ranges from femtomolar to nanomolar concentrations for both methods. Kinetic analyses using surface plasmon resonance (SPR) and biolayer interferometry (BLI) reveal that the variation in limit of detection is due to the variation in antibody affinity and that c-PLA outperforms traditional PLA for low-affinity antibodies. The lower background signal can be used to increase proximity probe concentration while maintaining a high signal-to-noise ratio, thereby enabling the use of low-affinity reagents in a homogeneous assay format. We anticipate that the advantages of c-PLA will be useful in a variety of clinical protein detection applications where high-affinity reagents are lacking.

Quantitative Detection of PEGylated Biomacromolecules in Biological Fluids by NMR

2016 ◽  
Vol 88 (7) ◽  
pp. 3730-3738 ◽  
Author(s):  
Rohan D. A. Alvares ◽  
Advait Hasabnis ◽  
R. Scott Prosser ◽  
Peter M. Macdonald
Keyword(s):  
Biological Fluids ◽  
Quantitative Detection

Robust SERS spectral analysis for quantitative detection of pyocyanin in biological fluids

2017 ◽  
Author(s):  
William Thrift ◽  
Arunima Bhattacharjee ◽  
Allon I. Hochbaum ◽  
Regina Ragan ◽  
Cuong Nguyen ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Biological Fluids ◽  
Quantitative Detection

Enhanced Chemiluminescent Assay for Measuring the Total Antioxidant Capacity of Serum, Saliva and Crevicular Fluid

1997 ◽  
Vol 34 (4) ◽  
pp. 412-421 ◽  
Author(s):  
I L C Chapple ◽  
G I Mason ◽  
I Garner ◽  
J B Matthews ◽  
G H Thorpe ◽  
...  
Keyword(s):  
Gingival Crevicular Fluid ◽  
Biological Fluids ◽  
Water Soluble ◽  
Clinical Samples ◽  
Antioxidant Defence ◽  
Oral Fluids ◽  
Water Soluble Vitamin ◽  
Total Antioxidant ◽  
Reproducible Method ◽  
Crevicular Fluid

This paper reports the development of an enhanced chemiluminescent (ECL) assay for measuring the total antioxidant (AO) capacity of serum, saliva and a fluid collectable from the gum margin called gingival crevicular fluid (GCF). The theory behind the assay is explained, and the optimum conditions for the assay, and for storage of reagents and clinical samples is described. Calibration lines were linear ( R≥0·99; P<0·0001) and the within batch coefficient of variations for a water soluble vitamin E analogue (Trolox), serum and saliva samples were <5%. In saliva and GCF, a characteristic AO response not seen in serum of the same patients, was identified. Total peripheral (serum) and local (saliva) AO capacities (μmol/L Trolox) were investigated in patients with ( n = 18) and without ( n = 16) adult periodontitis. Serum AO status did not differ between groups. Salivary total AO concentrations were lower in the periodontitis (P) group [175 (53)μmol/L] than in the nonperiodontitis (NP) group [254 (110)μmol/L1: P<0·01], as were saliva:serum AO ratio's [0·37 (0·11) versus 0·5 (0·18): P<0·01]. Periodontitis patients may have a reduced salivary AO concentration, which could result from, or predispose to, the damaging effects of reactive oxygen species (ROS). The potential for ROS production in the oral and periodontal environment may explain the presence of a specific antioxidant in oral fluids that is not detectable in serum. The ECL assay described provides a rapid, simple and reproducible method of measuring total antioxidant defence in small volumes of biological fluids.

scholarly journals Methods of Analysis for Anthocyanins in Plants and Biological Fluids

2004 ◽  
Vol 87 (1) ◽  
pp. 129-145 ◽  
Author(s):  
G Mazza ◽  
Juan E Cacace ◽  
Colin D Kay
Keyword(s):  
Biological Fluids ◽  
Multistep Method ◽  
Water Soluble ◽  
Plant Tissues ◽  
Vis Spectroscopy ◽  
Satisfactory Method ◽  
Zone Electrophoresis ◽  
Capillary Zone ◽  
Complexation Reactions ◽  
Layer Chromatography

Abstract Anthocyanins are the largest group of water-soluble pigments in the plant kingdom. They are responsible for most of the red, blue, and purple colors of fruits, vegetables, flowers, and other plant tissues or products. The analysis of anthocyanins is complex as a result of their ability to undergo structural transformations and complexation reactions. In addition, they are difficult to measure independently of other flavonoids, as they have similar structural and reactivity characteristics. Anthocyanins are generally extracted with weakly acidified alcohol-based solvents, followed by concentration (under vacuum), and purification of the pigments. Paper and/or thin-layer chromatography and UV-Vis spectroscopy have traditionally been used for the identification of anthocyanins. Capillary zone electrophoresis, a hybrid of chromatography and electrophoresis, is gaining popularity for the analysis of anthocyanins; however, liquid chromatography (LC) has become the standard method for identification and separation in most laboratories and may be used for both preparative and quantitative analysis. LC with mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are possibly the most powerful methods for the structural elucidation of anthocyanins available, to date. At present, the most satisfactory method for mixture analysis is the multistep method of separation, isolation, and quantification by LC with peak identification by MS and high-field NMR.

scholarly journals Determination of eugenitin in mouse blood by ultra-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study

2021 ◽  
Author(s):  
Chongliang Lin ◽  
Dezhen Song ◽  
Haodong Jiang ◽  
Lvqi Luo ◽  
Xi Bao ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Ultra Performance Liquid Chromatography ◽  
Quantitative Detection ◽  
Syzygium Aromaticum ◽  
Mouse Blood ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass

Abstract Eugenitin is a non-volatile chromone derivative which is always found in dried flower buds of Syzygium aromaticum L. (Merr.) & L.M. Perry. Until now, there were no reports about the pharmacokinetics of eugenitin in biological fluids. A UPLC-MS/MS method developed to determine eugenitin in mouse blood. The blood samples were prepared by protein precipitation with acetonitrile. Chrysin (internal standard, IS) and eugenitin were gradient eluted by mobile phase of acetonitrile and water (0.1% formic acid) in a BEH C18 column. The multiple reaction monitoring (MRM) of m/z 221.1→206.0 for eugenitin and m/z 255.1→152.9 for IS with an electrospray ionization (ESI) source was used for quantitative detection. The calibration curve ranged from 0.5 to 500 ng/mL (r > 0.995). The accuracy ranged from 98 to 113%, the precision was less than 12%, and the matrix effect was between 86 and 94%, the recovery was better than 81%. The developed method was successfully used for pharmacokinetics of eugenitin in mice after intravenous (5 mg/kg) and oral (20 mg/kg) administration, and the absolute availability of eugenitin was 12%.

A comparison between the antioxidant and peroxynitrite-scavenging functions of the vitamin E metabolites alpha- and gamma-carboxyethyl-6-hydroxychromans

2004 ◽  
Vol 74 (5) ◽  
pp. 362-373 ◽  
Author(s):  
Galli ◽  
Piroddi ◽  
Iannone ◽  
Pagliarani ◽  
Tomasi ◽  
...  
Keyword(s):  
Vitamin E ◽  
Lipid Oxidation ◽  
Biological Fluids ◽  
Inhibitory Effect ◽  
Experimental Models ◽  
Water Soluble ◽  
Ldl Oxidation ◽  
Similar Concentration ◽  
Dependent Inhibition

Carboxyethyl-6-hydroxychromans (CEHC) are vitamin E metabolites with proposed in vitro antioxidant function. In this study we compared the antioxidant potency of the two main CEHC metabolites found in biological fluids (i.e., alpha-CEHC and gamma-CEHC) using two different experimental models of lipid oxidation: 1) plasma diluted 1/50 vol/vol in phosphate buffered saline (PBS) exposed to 50 muM Cu2+ ions, and 2) LDL (100 mug of proteins) exposed to different pro-oxidants as 2.5 muM Cu2+, 1 mM of the water soluble peroxyl radical generator 2,2'-Azobis(2-amidinopropane) hydrochloride (AAPH) and human macrophages (4 x 105 cells). Moreover, the two CEHC homologues were assessed for the inhibitory effect on the peroxynitrite (ONOO–)-induced nitration of tyrosine (Tyr). The results showed that in the concentration range 0.015–5 muM the CEHC metabolites and the hydrosoluble analogue Trolox exert similar concentration-dependent inhibition of the Cu2+-induced lipid oxidation of plasma. After in vitro exposure to tert-butyl hydroperoxide/Fe2+, CEHC formed chromanoxyl radicals with electron spin resonance spectra matching exactly those of their parent tocopherols. The LDL oxidation induced by AAPH or Cu2+ was significantly and similarly inhibited by 1 muM of both the CEHC homologues and Trolox. gamma-CEHC showed a slight but significantly higher inhibition of the macrophage-induced low-density lipoprotein (LDL) oxidation than alpha-CEHC. Both the CEHC homologues inhibit Tyr nitration induced by ONOO–. However, gamma-CEHC produced a slightly greater inhibitory effect than alpha-CEHC through the formation of the nitrated congener 5-nitro-gamma-CEHC. In all the systems under investigation, low nanomolar concentrations of CEHC (i.e., the concentration range in the blood of subjects with normal dietary intake of vitamin E) produced feeble antioxidant effects. In conclusion, gamma-CEHC and alpha-CEHC show similar concentration-dependent inhibition of plasma and LDL lipid oxidation. gamma-CEHC has a fairly higher potency than alpha-CEHC as ONOO– scavenger through the formation of 5-nitro-gamma-CEHC. CEHC metabolites show the same in vitro antioxidant chemistry of their parent tocopherols, but the characteristic hydrophilicity of these metabolites could result in different biopotency and roles. Further studies are needed to clarify whether CEHC could contribute to the antioxidant network in biological fluids and tissues.

Sign in / Sign up

Export Citation Format

Share Document