scholarly journals A Fluorescence Inner-Filter Effect Based Sensing Platform for Turn-On Detection of Glutathione in Human Serum

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 228 ◽  
Author(s):  
Shurong Tang ◽  
Xiuhua You ◽  
Quanhui Fang ◽  
Xin Li ◽  
Guangwen Li ◽  
...  
Keyword(s):  
Human Serum ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Inner Filter Effect ◽  
Disease Diagnosis ◽  
Fluorescent Properties ◽  
Serum Samples ◽  
Turn On ◽  
Filter Effect ◽  
Sensing Platform

A novel turn-on fluorescence assay was developed for the rapid detection of glutathione (GSH) based on the inner-filter effect (IFE) and redox reaction. Molybdenum disulfide quantum dots (MoS2 QDs), which have stable fluorescent properties, were synthesized with hydrothermal method. Manganese dioxide nanosheets (MnO2 NSs) were prepared by exfoliating the bulk δ-MnO2 material in bovine serum albumin (BSA) aqueous solution. The morphology structures of the prepared nanoparticles were characterized by transmission electron microscope (TEM). Studies have shown that the fluorescence of MoS2 QDs could be quenched in the presence of MnO2 NSs as a result of the IFE, and is recovered after the addition of GSH to dissolve the MnO2 NSs. The fluorescence intensity showed a good linear relationship with the GSH concentration in the range 20–2500 μM, the limit of detection was 1.0 μM. The detection method was applied to the analysis of GSH in human serum samples. This simple, rapid, and cost-effective method has great potential in analyzing GSH and in disease diagnosis.

scholarly journals A Fluorescent Aptasensor Based on Assembled G-Quadruplex and Thioflavin T for the Detection of Biomarker VEGF165

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Zheng ◽  
Shunxiang Gao ◽  
Jihong Wu ◽  
Xiaobo Hu
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Disease Diagnosis ◽  
Serum Samples ◽  
Signal Molecule ◽  
Diagnosis And Prognosis ◽  
Cost Effective Approach ◽  
G Quadruplex ◽  
Diabetic Eye Disease ◽  
Fluorescent Aptasensor

VEGF165, a regulator of angiogenesis, has been widely used as a serum biomarker for a number of human diseases, including cancer, rheumatoid arthritis, bronchial asthma, and diabetic eye disease. The rapid, accurate, and convenient detection of VEGF165 is a crucial step in effective healthcare monitoring, disease diagnosis, and prognosis assessment. In this study, a fluorescent aptasensor based on an assembled G-quadruplex and the signal molecule ThT was developed for VEGF165 detection. First, G-rich DNA fragments were assembled at both ends of the anti-VEGF165 aptamer, and the B-DNA form was converted into a G-quadruplex structure aptamer (G4-Apt). Then, ThT was introduced, and the G-quadruplex significantly enhanced the fluorescence intensity of the bound ThT. When VEGF165 was present, the higher affinity of the aptamer to the target protein allowed the G4-Apt/VEGF165 complex to form and release ThT, which emitted only weak fluorescence in the free state. Therefore, the aptasensor exhibited a good linear detection window from 1.56 to 25 nM VEGF165, with a limit of detection of 0.138 nM. In addition, the aptasensor was applied to detect VEGF165 in clinical serum samples, showing good accuracy, reproducibility, and stability. These results indicate that our developed fluorescent aptasensor can potentially be a reliable, convenient, and cost-effective approach for the sensitive, specific, and rapid detection of the VEGF165 biomarker.

scholarly journals Methodology and Applications of Disease Biomarker Identification in Human Serum

2007 ◽  
Vol 2 ◽  
pp. 117727190700200 ◽  
Author(s):  
Ziad J. Sahab ◽  
Suzan M. Semaan ◽  
Qing-Xiang Amy Sang
Keyword(s):  
Human Serum ◽  
Protein Separation ◽  
High Sensitivity ◽  
Disease Diagnosis ◽  
Plasma Lipoproteins ◽  
Great Promise ◽  
Protein Biomarkers ◽  
Serum Samples ◽  
Disease Biomarkers ◽  
Diagnosis And Prognosis

Biomarkers are biomolecules that serve as indicators of biological and pathological processes, or physiological and pharmacological responses to a drug treatment. Because of the high abundance of albumin and heterogeneity of plasma lipoproteins and glycoproteins, biomarkers are difficult to identify in human serum. Due to the clinical significance the identification of disease biomarkers in serum holds great promise for personalized medicine, especially for disease diagnosis and prognosis. This review summarizes some common and emerging proteomics techniques utilized in the separation of serum samples and identification of disease signatures. The practical application of each protein separation or identification technique is analyzed using specific examples. Biomarkers of cancers of prostate, breast, ovary, and lung in human serum have been reviewed, as well as those of heart disease, arthritis, asthma, and cystic fibrosis. Despite the advancement of technology few biomarkers have been approved by the Food and Drug Administration for disease diagnosis and prognosis due to the complexity of structure and function of protein biomarkers and lack of high sensitivity, specificity, and reproducibility for those putative biomarkers. The combination of different types of technologies and statistical analysis may provide more effective methods to identify and validate new disease biomarkers in blood.

scholarly journals Spectrofluorimetric Determination of Hydrochlorothiazide by a Carbon Dots-Based Probe via Inner Filtering Effect and Resonance Rayleigh Scattering

2022 ◽  
Author(s):  
Ali Ghafarloo ◽  
Reza Sabzi ◽  
Naser Samadi ◽  
Hamed Hamishehkar
Keyword(s):  
Carbon Dots ◽  
Rayleigh Scattering ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Emission Spectra ◽  
Cost Effective ◽  
Inner Filter Effect ◽  
Resonance Rayleigh Scattering ◽  
Excitation Spectra ◽  
One Pot

Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (HCTZ) via inner filter effect (IFE) and resonance Rayleigh scattering (RRS). The as-prepared CDs had wide emission spectra, excitation-dependent emission, high solubility, high stability, and visible fluorescence light with a quantum yield of up to 11%. The absorption of HCTZ overlapped with the excitation spectra of CDs. Therefore, CDs represented excellent quenching due to IFE when HCTZ was gradually added. Furthermore, this fluorescent sensor was successfully used to quantify HCTZ in the linear ranges (0.17-2.50 μg mL-1) with the limit of detection of 0.11 μg mL-1. The sensing system was simple as no surface functionalization was required for CDs, leading to less laborious steps and more cost-effective synthesis. The reaction time was short, i.e., less than 2 min, indicating a simple approach for rapid analysis of HCTZ. By optimizing conditions, successful measurements were carried out on pharmaceutical tablets.

scholarly journals Development of a Dot-Immunoenzyme Filtration Assay for the Detection of Enterovirus 71 Antigen in Human Serum via Immunoglobulin M

2012 ◽  
Vol 40 (3) ◽  
pp. 1122-1129
Author(s):  
A Zhang ◽  
M Zhang ◽  
H Zhang ◽  
H Li ◽  
Q Liu
Keyword(s):  
Human Serum ◽  
Healthy Adult ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Cost Effective ◽  
Immunoglobulin M ◽  
Healthy Controls ◽  
Structural Protein ◽  
Serum Samples ◽  
Effective Screening

OBJECTIVES: This study evaluated the sensitivity and specificity of a rapid, sensitive dot-immunoenzyme filtration assay to detect enterovirus 71 (EV71) antigen in serum samples from paediatric patients with hand, foot and mouth disease (HFMD), through detection of anti-EV71 immunoglobulin (Ig)M. METHODS: Serum samples from HFMD patients and healthy adult controls were evaluated for the presence of anti-EV71 IgM using a dot-immunoenzyme filtration assay (DIEFA). The results were compared with those obtained using a dot-immunogold filtration assay (DIGFA). The EV71 structural protein VP1 was used as the antigen for both assays. RESULTS: Serum samples from 72 HFMD patients and 54 healthy controls were evaluated. The DIGFA procedure showed a sensitivity of 98.5% and a specificity of 100%, whereas the DIEFA procedure showed a sensitivity of 98.6% and a specificity of 98.0%. There were no significant differences between the assays in either specificity or sensitivity. CONCLUSION: The DIEFA procedure developed in this study has potential as a rapid, simple, sensitive and cost-effective screening technique for detecting EV71 antigen in serum samples from patients with HFMD.

scholarly journals Cytidine-stabilized copper nanoclusters as a fluorescent probe for sensing of copper ions and hemin

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9057-9062 ◽  
Author(s):  
Yong Wang ◽  
Tianxia Chen ◽  
Zhengtao Zhang ◽  
Yongnian Ni
Keyword(s):  
Fluorescent Probe ◽  
Copper Ions ◽  
Simultaneous Detection ◽  
Inner Filter Effect ◽  
Copper Nanoclusters ◽  
Turn On ◽  
Filter Effect ◽  
Fluorescence Turn On

A sensitive and selective fluorescence “turn on–off” strategy for simultaneous detection of Cu2+and hemin was proposed on the basis of the formation of fluorescent CuNCs and the inner filter effect of hemin on the fluorescence of the CuNCs.

Monoclonal antibodies evaluated for use in a screening assay for conjugates of human serum albumin and pyridoxal 5'-phosphate.

1989 ◽  
Vol 35 (8) ◽  
pp. 1756-1760 ◽  
Author(s):  
B B Miller ◽  
W E Turner
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Human Serum Albumin ◽  
Human Serum ◽  
Limit Of Detection ◽  
Screening Method ◽  
Serum Samples ◽  
Screening Assay ◽  
Antibody Avidity ◽  
Negative Results

Abstract This enzyme immunoassay (EIA) was developed to measure pyridoxal 5'-phosphate bound to albumin (PLP-HSA) in human serum. The monoclonal antibody titer was 1:2000 and a sequential saturation analysis curve, prepared with samples containing from 10 to 1000 nmol/L, showed a 50% inhibition of antibody at 50 nmol of the conjugate per liter. The lower limit of detection for PLP-HSA was 10 nmol/L, a sensitivity 1000-fold greater than that for any potential interferent. When serum samples gave negative results in the assay, we compared the antigenicity of the principal sites for PLP binding on HSA. It was apparent that the preferred physiological site was not antigenic; however, three additional sites for PLP binding on HSA elicited comparable antibody avidity. This EIA is potentially quite sensitive and specific for PLP-HSA, but considerable additional effort is required to convert serum PLP to an HSA-bound form detectable in the assay, which limits its application as a screening method.

A facile ratiometric sensing platform based on inner filter effect for hypochlorous acid detection

2020 ◽  
Vol 325 ◽  
pp. 128766
Author(s):  
Chenggong Xu ◽  
Yanmei Zhou ◽  
Yunhao Zhou ◽  
Zhaoge Li ◽  
Xiaojun Peng
Keyword(s):  
Hypochlorous Acid ◽  
Inner Filter Effect ◽  
Ratiometric Sensing ◽  
Filter Effect ◽  
Sensing Platform

scholarly journals Graphitic-Phase C3N4 Nanosheets Combined with MnO2 Nanosheets for Sensitive Fluorescence Quenching Detection of Parathion-Methyl

2021 ◽  
Author(s):  
Bicheng Liu ◽  
Sihao Wu ◽  
Zoujun Peng ◽  
Jiahan Rui ◽  
Ping Qiu
Keyword(s):  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Organophosphorus Pesticides ◽  
Cost Effective ◽  
Inner Filter Effect ◽  
Enzymatic Hydrolysate ◽  
Analytical Instruments ◽  
Dimethyl Phosphate ◽  
User Friendly

Abstract In this study, we have developed a sensitive approach to measure organophosphorus pesticides (OPs) using graphitic-phase C3N4 nanosheets (g-C3N4) combined with a nanomaterial-based quencher MnO2 nanosheets (MnO2 NS). Because MnO2 NS could quench the fluorescence of g-C3N4 via the inner-filter effect (IFE), the enzymatic hydrolysate (thiocholine, TCh) can efficiently trigger the decomposition of MnO2 nanosheets in the presence of acetylcholinesterase (AChE) and acetylthiocholine, resulting in the fluorescence recovery of g-C3N4. OPs, as inhibitors for AChE activity, can prevent the generation of TCh and decomposition of MnO2 nanosheets, accompanied by fluorescence quenching again. So the AChE-ATCh-MnO2-g-C3N4 system can be utilized to detect OPs quantitatively based on the g-C3N4 fluorescence. Under the optimum conditions, the linear range for the determination of parathion-methyl (PM) and 2,2-dichlorovinyl dimethyl phosphate (DDVP) were found in the range of 0.1-2.1 ng/mL with a limit of detection of 0.069 ng/mL, and 0.5-16 ng/mL with a limit of detection of 0.069 ng/mL, respectively. Finally, this method was exploited for the monitoring of PM in real samples. The advantages of the assay are user-friendly, easy-to-ease, cost-effective compared to sophisticated analytical instruments.

scholarly journals Reusable, Noninvasive, and Sensitive Fluorescence Enhanced ZnO-Nanorod-Based Microarrays for Quantitative Detection of AFP in Human Serum

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Saima Rafique ◽  
Farukh Kiyani ◽  
Sumbal Jawaid ◽  
Rubina Nasir ◽  
Mahmoosh Ahmad ◽  
...  
Keyword(s):  
Human Serum ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Zno Nanorods ◽  
Protein Microarrays ◽  
Great Promise ◽  
Quantitative Detection ◽  
Zno Nanorod ◽  
Serum Samples ◽  
Protein Assay

The fabrication of sensitive protein microarrays such as PCR used in DNA microarray is challenging due to lack of signal amplification. The development of microarrays is utilized to improve the sensitivity and limitations of detection towards primal cancer detection. The sensitivity is enhanced by the use of ZnO-nanorods and is investigated as a substrate which enhance the florescent signal to diagnose the hepatocellular carcinoma (HCC) at early stages. The substrate for deposition of ZnO-nanorods is prepared by the conventional chemical bath deposition method. The resultant highly dense ZnO-nanorods enhance the fluorescent signal 7.2 times as compared to the substrate without ZnO-nanorods. The microarray showed sensitivity of 1504.7 ng ml-1 and limit of detection of 0.1 pg ml-1 in wide dynamic range of 0.05 pg-10 μg ml-1 for alpha fetoprotein (AFP) detection in 10% human serum. This immunoassay was successfully applied for human serum samples to detect tumor marker with good recoveries. The ZnO-nanorod substrate is a simple protein microarray which showed a great promise for developing a low-cost, sensitive, and high-throughput protein assay platform for several applications in both fundamental research and clinical diagnosis.

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