A DNAzyme-based label-free fluorescent probe for guanosine-5′-triphosphate detection

The Analyst ◽  
2020 ◽  
Vol 145 (21) ◽  
pp. 6948-6954
Author(s):  
Chengzhen Hu ◽  
Kemei Jiang ◽  
Zihao Shao ◽  
Minqing Shi ◽  
Hong-Min Meng
Keyword(s):  
Human Serum ◽  
Fluorescent Probe ◽  
Label Free ◽  
Serum Samples ◽  
Human Serum Samples

A DNAzyme-based fluorescent probe with self-phosphorylation ability for label-free and sensitive GTP detection in buffer and human serum samples.

scholarly journals Single-step label-free nanowell immunoassay accurately quantifies serum stress hormones within minutes

2021 ◽  
Vol 7 (27) ◽  
pp. eabf4401
Author(s):  
S. Reza Mahmoodi ◽  
Pengfei Xie ◽  
Daniel P. Zachs ◽  
Erik J. Peterson ◽  
Rachel S. Graham ◽  
...  
Keyword(s):  
Human Serum ◽  
Real Time ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Label Free ◽  
Serum Samples ◽  
Electrode Gap ◽  
Buffer Solution ◽  
Human Serum Samples ◽  
Free Cortisol

A non-faradaic label-free cortisol sensing platform is presented using a nanowell array design, in which the two probe electrodes are integrated within the nanowell structure. Rapid and low volume (≤5 μl) sensing was realized through functionalizing nanoscale volume wells with antibodies and monitoring the real-time binding events. A 28-well plate biochip was built on a glass substrate by sequential deposition, patterning, and etching steps to create a stack nanowell array sensor with an electrode gap of 40 nm. Sensor response for cortisol concentrations between 1 and 15 μg/dl in buffer solution was recorded, and a limit of detection of 0.5 μg/dl was achieved. Last, 65 human serum samples were collected to compare the response from human serum samples with results from the standard enzyme-linked immunosorbent assay (ELISA). These results confirm that nanowell array sensors could be a promising platform for point-of-care testing, where real-time, laboratory-quality diagnostic results are essential.

Simultaneous Monitoring of Febuxostat and Uric Acid in Human Serum Samples Using the Direct Square-Wave Voltammetric Method

2019 ◽  
Vol 15 (6) ◽  
pp. 678-684
Author(s):  
Biljana Nigović ◽  
Jakov Vlak
Keyword(s):  
Uric Acid ◽  
Human Serum ◽  
Oxidase Inhibitor ◽  
Serum Samples ◽  
Boron Doped Diamond ◽  
Fast Analysis ◽  
Xanthine Oxidase Inhibitor ◽  
Voltammetric Method ◽  
Square Wave ◽  
Human Serum Samples

Background: High uric acid serum level, hyperuricemia, is now associated with many diseases such as gout, chronic kidney disease, hypertension, coronary artery disease and diabetes. Febuxostat is a novel selective xanthine oxidase inhibitor approved for the treatment of hyperuricemia. Objective: The aim of this study was to develop a first analytical method for the simultaneous determination of febuxostat and uric acid. Methods: An unmodified boron-doped diamond electrode provided concurrent quantitation of drug at low levels and uric acid, which has clinical significance in the diagnosis and therapy of hyperuricemia, at relatively high concentrations. The direct square-wave voltammetric method was applied to the analysis of both analytes in human serum samples. Results: Under the optimized conditions, the linear response of peak current on febuxostat concentration was achieved in the range from 7.5 × 10-7 to 3 × 10-5 M, while uric acid showed two linear ranges of 5 × 10-6 - 5 × 10-5 M and 5 × 10-5 - 2 × 10-4 M. The method was successfully utilised for quantification of both analytes in human serum samples. Good recoveries were obtained without interference from common inorganic cations and anions as well as glucose, dopamine, ascorbic and folic acids at concentrations expected in physiological conditions. Conclusion: The great benefits of developed method are fast analysis (only 7.5 s for run), low cost and simplicity of performance.

A rat granulosa cell plasminogen activator bioassay for FSH in human serum

1990 ◽  
Vol 126 (1) ◽  
pp. 159-168 ◽  
Author(s):  
A. N. Thakur ◽  
R. Coles ◽  
A. Sesay ◽  
B. Earley ◽  
H. S. Jacobs ◽  
...  
Keyword(s):  
Human Serum ◽  
Plasminogen Activator ◽  
Granulosa Cell ◽  
Serum Samples ◽  
Glycoprotein Hormone ◽  
Assay Sensitivity ◽  
Serum Factors ◽  
Human Serum Samples ◽  
Heat Treated ◽  
Fsh Bioactivity

ABSTRACT A previously described in-vitro rat granulosa cell plasminogen activator bioassay for FSH has been modified and applied in the assay of human serum. This modified method consists of exposing the diethylstilboestrol-stimulated granulosa cells from 25- to 26-day-old rats to FSH or test substance for 3·5 h in wells coated with 125I-labelled fibrinogen and treated with thrombin. Following stimulation with FSH, the dose-related production of plasminogen activator was measured as the degree of 125I-labelled fibrinolysis in the presence of added plasminogen. Using the urinary FSH/LH bioassay reference preparation as the assay standard, the useful range of the assay was 0·3–15IU/l, with an assay sensitivity of 0·3 IU/l. As determined using purified glycoprotein hormone preparations, the assay was highly specific for FSH. The minor degree of FSH bioactivity measured in some of the hormone preparations was accounted for by the amount of FSH contamination in these preparations. To abolish interference caused by unknown serum factors, we heat-treated the serum samples for 15 min at 56 °C before the assay. The results indicated that neither immunoreactivity nor bioactivity was affected by this treatment. Furthermore, heat-treated human sera gave responses parallel to the standard curve at the three dose levels (2, 4 and 8 μl) studied. We used this bioassay to estimate the FSH-like bioactivity in 15 human serum samples. The estimates of immunoreactive FSH in these samples correlated well with the corresponding FSH bioactivity (r = 0·745, n = 15 and P < 0·05). The results indicate that with this sensitive and rapid (completed within 24 h) bioassay, it should be possible to measure FSH bioactivity in heat-treated human serum samples. Journal of Endocrinology (1990) 126, 159–168

scholarly journals Evaluation of PCR-based assay in human serum samples for diagnosis of fatal cases of spotted fever group rickettsiosis

2009 ◽  
Vol 15 ◽  
pp. 232-234 ◽  
Author(s):  
E.M Mendes do Nascimento ◽  
S. Colombo ◽  
T.K. Nagasse-Sugahara ◽  
R.N. Angerami ◽  
M.R. Resende ◽  
...  
Keyword(s):  
Human Serum ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
Serum Samples ◽  
Human Serum Samples

Simultaneous determination of ascorbic and uric acids and dopamine in human serum samples using three-way calibration with data from square wave voltammetry

2016 ◽  
Vol 129 ◽  
pp. 205-212 ◽  
Author(s):  
Adrian Marcelo Granero ◽  
Gastón Darío Pierini ◽  
Sebastián Noel Robledo ◽  
María Susana Di Nezio ◽  
Héctor Fernández ◽  
...  
Keyword(s):  
Human Serum ◽  
Simultaneous Determination ◽  
Square Wave Voltammetry ◽  
Serum Samples ◽  
Square Wave ◽  
Human Serum Samples ◽  
Wave Voltammetry

scholarly journals A Novel, Rapid, and Low-Volume Assay for Therapeutic Drug Monitoring of Posaconazole and Other Long-Chain Azole-Class Antifungal Drugs

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Gregory R. Wiedman ◽  
Yanan Zhao ◽  
David S. Perlin
Keyword(s):  
Liquid Chromatography ◽  
Therapeutic Drug Monitoring ◽  
Human Serum ◽  
Drug Monitoring ◽  
Fungal Infections ◽  
Antifungal Drugs ◽  
Therapeutic Drug ◽  
Serum Samples ◽  
Human Serum Samples ◽  
Long Chain

ABSTRACT Clinicians need a better way to accurately monitor the concentration of antimicrobials in patient samples. In this report, we describe a novel, low-sample-volume method to monitor the azole-class antifungal drug posaconazole, as well as certain other long-chain azole-class antifungal drugs in human serum samples. Posaconazole represents an important target for therapeutic drug monitoring (TDM) due to its widespread use in treating invasive fungal infections and well-recognized variability of pharmacokinetics. The current “gold standard” requires trough and peak monitoring through high-pressure liquid chromatography (HPLC) or liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Other methods include bioassays that use highly susceptible strains of fungi in culture plates or 96-well formats to monitor concentrations. Currently, no method exists that is both highly accurate in detecting free drug concentrations and is also rapid. Herein, we describe a new method using reduced graphene oxide (rGO) and a fluorescently labeled aptamer, which can accurately assess clinically relevant concentrations of posaconazole and other long-chain azole-class drugs in little more than 1 h in a total volume of 100 µl. IMPORTANCE This work describes an effective assay for TDM of long-chain azole-class antifungal drugs that can be used in diluted human serum samples. This assay will provide a quick, cost-effective method for monitoring concentrations of drugs such as posaconazole that exhibit well-documented pharmacokinetic variability. Our rGO-aptamer assay has the potential to improve health care for those struggling to treat fungal infections in rural or resource-limited setting.

scholarly journals Cryogenic zone compression GC-HRTOFMS for the measurement of PCB-153 and DDE in 20 μL serum samples

2016 ◽  
Vol 8 (2) ◽  
pp. 249-255 ◽  
Author(s):  
B. L'Homme ◽  
J.-F. Focant
Keyword(s):  
Human Serum ◽  
Human Exposure ◽  
Proof Of Concept ◽  
Serum Samples ◽  
Human Serum Samples

Human exposure to POPs is of concern and typical biomonitoring studies require large amounts of blood (5–75 mL) from participants. As a proof of concept, we developed a miniaturized method based on MEPS and CZC applied to GC-HRTOFMS for the measurement of markers of exposure (PCB-153, DDE) in 20 μL human serum samples.

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