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

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.

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

Sensors ◽

10.3390/s19020228 ◽

2019 ◽

Vol 19 (2) ◽

pp. 228 ◽

Cited By ~ 3

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.

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Self-Assembly of Functional Nucleic Acid-Based Colorimetric Competition Assay for the Detection of Immunoglobulin E

Sensors ◽

10.3390/s19102224 ◽

2019 ◽

Vol 19 (10) ◽

pp. 2224 ◽

Cited By ~ 1

Author(s):

Xuexia Lin ◽

Caiyun Yu ◽

Honggui Lin ◽

Cui Wang ◽

Jianlong Su ◽

...

Keyword(s):

Self Assembly ◽

Immunoglobulin E ◽

Limit Of Detection ◽

Solid Phase ◽

Colorimetric Assay ◽

Cost Effective ◽

Enzyme Linked Immunosorbent Assay ◽

Cost Effective Approach ◽

G Quadruplex ◽

Functional Nucleic Acids

In this work, we have developed a simple and rapid colorimetric assay for the detection of immunoglobulin E (IgE) using functional nucleic acids (FNAs) and a solid-phase competition enzyme-linked immunosorbent assay (ELISA). The FNAs including aptamer of recombinant IgE, G-quadruplex and its complementary fragments were immobilized on 96-well microplates to achieve recognition and detection of IgE in biological samples. The G-quadruplex DNAzyme catalyzed 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS)-hemin-H2O2 system was used to improve the sensitivity of colorimetric assay. In the presence of IgE, the hairpin structure and G-quadruplex would be destroyed, resulting in the inactivation of DNAzyme and subsequent reduction of its absorbance. This cost-effective approach detected IgE in the linear range from 5.0 pg/mL to 500 ng/mL, with the limit of detection (LOD) of 2.0 pg/mL, under optimal conditions. Moreover, the developed method was successfully applied to the rapid detection of IgE in human urine, indicating a great potentiality of this approach in clinical diagnosis and other biomedical applications.

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Methodology and Applications of Disease Biomarker Identification in Human Serum

Biomarker Insights ◽

10.1177/117727190700200034 ◽

2007 ◽

Vol 2 ◽

pp. 117727190700200 ◽

Cited By ~ 54

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.

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Machine Learning Perspective in Cancer Research

Handbook of Research on Disease Prediction Through Data Analytics and Machine Learning - Advances in Medical Diagnosis, Treatment, and Care ◽

10.4018/978-1-7998-2742-9.ch008 ◽

2021 ◽

pp. 142-163

Author(s):

Aman Sharma ◽

Rinkle Rani

Keyword(s):

Machine Learning ◽

Cancer Research ◽

Expression Profiles ◽

Genetic Diseases ◽

Cost Effective ◽

Healthcare Sector ◽

Diagnosis And Prognosis ◽

Cost Effective Approach ◽

Next Generation Sequencing Ngs ◽

Generation Sequencing

Advancement in genome sequencing technology has empowered researchers to think beyond their imagination. Researchers are trying their hard to fight against various genetic diseases like cancer. Artificial intelligence has empowered research in the healthcare sector. Moreover, the availability of opensource healthcare datasets has motivated the researchers to develop applications which can help in early diagnosis and prognosis of diseases. Further, next-generation sequencing (NGS) has helped to look into detailed intricacies of biological systems. It has provided an efficient and cost-effective approach with higher accuracy. The advent of microRNAs also known as small noncoding genes has begun the paradigm shift in oncological research. We are now able to profile expression profiles of RNAs using RNA-seq data. microRNA profiling has helped in uncovering their relationship in various genetic and biological processes. Here in this chapter, the authors present a review of the machine learning perspective in cancer research.

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Low temperature isothermal amplification of microsatellites drastically reduces stutter artifact formation and improves microsatellite instability detection in cancer

Nucleic Acids Research ◽

10.1093/nar/gkz811 ◽

2019 ◽

Vol 47 (21) ◽

pp. e141-e141 ◽

Cited By ~ 3

Author(s):

Antoine Daunay ◽

Alex Duval ◽

Laura G Baudrin ◽

Olivier Buhard ◽

Victor Renault ◽

...

Keyword(s):

Low Temperature ◽

Microsatellite Instability ◽

Tandem Repeats ◽

Limit Of Detection ◽

Cost Effective ◽

Isothermal Amplification ◽

Dna Repeat ◽

Cost Effective Approach ◽

Living Organisms ◽

Artifact Formation

Abstract Microsatellites are polymorphic short tandem repeats of 1–6 nucleotides ubiquitously present in the genome that are extensively used in living organisms as genetic markers and in oncology to detect microsatellite instability (MSI). While the standard analysis method of microsatellites is based on PCR followed by capillary electrophoresis, it generates undesirable frameshift products known as ‘stutter peaks’ caused by the polymerase slippage that can greatly complicate the analysis and interpretation of the data. Here we present an easy multiplexable approach replacing PCR that is based on low temperature isothermal amplification using recombinase polymerase amplification (LT-RPA) that drastically reduces and sometimes completely abolishes the formation of stutter artifacts, thus greatly simplifying the calling of the alleles. Using HT17, a mononucleotide DNA repeat that was previously proposed as an optimal marker to detect MSI in tumor DNA, we showed that LT-RPA improves the limit of detection of MSI compared to PCR up to four times, notably for small deletions, and simplifies the identification of the mutant alleles. It was successfully applied to clinical colorectal cancer samples and enabled detection of MSI. This easy-to-handle, rapid and cost-effective approach may deeply improve the analysis of microsatellites in several biological and clinical applications.

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Concentration of Penicillin G in Jawbone Affected by Antiresorptive Agent-Related Osteonecrosis Following a Single Preoperative Dose

Antibiotics ◽

10.3390/antibiotics10010017 ◽

2020 ◽

Vol 10 (1) ◽

pp. 17

Author(s):

Philipp Poxleitner ◽

Michael Andreas Ermer ◽

Rainer Trittler ◽

Carolin Lena Feuerstein ◽

Jörg-Elard Otten ◽

...

Keyword(s):

Antibiotic Therapy ◽

High Performance ◽

Limit Of Detection ◽

Cost Effective ◽

Osteonecrosis Of The Jaw ◽

Penicillin G ◽

Serum Samples ◽

Median Concentration ◽

Antiresorptive Agent ◽

Antiresorptive Agents

The aim of this study was to evaluate the concentration of penicillin G in bone affected by antiresorptive agent-related osteonecrosis of the jaw (ARONJ) following a single preoperative dose of 10 million international units (6000 mg). ARONJ is a major concern in patients administered antiresorptive agents for conditions associated with pathologically increased bone resorption. Antibiotic therapy is a key component of most treatment approaches for ARONJ and penicillin based regimens, providing a cost effective therapy option with a favorable side effect profile, are administered most frequently. In this study, high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) was applied to evaluate penicillin G concentration in serum and bone samples of 19 patients suffering from ARONJ and undergoing surgical treatment under perioperative intravenous (IV) antibiotic therapy. Penicillin G bone concentrations were above the limit of detection (0.1 μg/g bone tissue) in 16 out of 19 samples, with a median concentration of 2.7 μg/g (range 0.1–8.8 μg/g). Penicillin G concentrations in intraoperative serum samples were above the limit of detection in all serum samples, with a median concentration of 116 μg/mL (range 1–232 μg/mL). Thus, considering bacteria frequently found in ARONJ lesions, penicillin G at levels providing adequate antimicrobial activity was detected in the serum and 16 out of 19 osteonecrotic lesions of patients suffering from ARONJ.

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Electroencephalography as a Non-Invasive Biomarker of Alzheimer’s Disease: A Forgotten Candidate to Substitute CSF Molecules?

International Journal of Molecular Sciences ◽

10.3390/ijms221910889 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10889

Author(s):

Paloma Monllor ◽

Ana Cervera-Ferri ◽

Maria-Angeles Lloret ◽

Daniel Esteve ◽

Begoña Lopez ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Molecular Markers ◽

Cost Effective ◽

Disease Diagnosis ◽

Therapeutic Interventions ◽

Underlying Process ◽

Non Invasive ◽

Diagnosis And Prognosis ◽

Over Time

Biomarkers for disease diagnosis and prognosis are crucial in clinical practice. They should be objective and quantifiable and respond to specific therapeutic interventions. Optimal biomarkers should reflect the underlying process (pathological or not), be reproducible, widely available, and allow measurements repeatedly over time. Ideally, biomarkers should also be non-invasive and cost-effective. This review aims to focus on the usefulness and limitations of electroencephalography (EEG) in the search for Alzheimer’s disease (AD) biomarkers. The main aim of this article is to review the evolution of the most used biomarkers in AD and the need for new peripheral and, ideally, non-invasive biomarkers. The characteristics of the EEG as a possible source for biomarkers will be revised, highlighting its advantages compared to the molecular markers available so far.

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Label-Free Fluorescent Aptasensor for Adenosine Triphosphate Detection Using SYBR Gold as a Probe

Applied Spectroscopy ◽

10.1177/00037028211028668 ◽

2021 ◽

pp. 000370282110286

Author(s):

Jun Deng ◽

Mengyu Niu ◽

Xingquan Liu ◽

Jin Feng ◽

Shuang Ji ◽

...

Keyword(s):

Adenosine Triphosphate ◽

Cost Effective ◽

Random Coil ◽

Label Free ◽

Serum Samples ◽

Exonuclease I ◽

Cell Extracts ◽

G Quadruplex ◽

Sybr Gold ◽

Other Substances

In this experimental research, a label-free sensing strategy is developed and employed to detect adenosine triphosphate with utilization of aptamers, including exonuclease I and SYBR Gold. The conformation of aptamers bonding to the specific target molecule (ATP) is transformed into an antiparallel G-quadruplex structure from a random coil. Afterwards, considering the unfolded aptamers are the preferred substrates for exonuclease I, the addition of exonuclease I is used so as to digest unfolded aptamers in the mixture in a selective manner. In the follow-up study, in order to strengthen the fluorescence intensity, SYBR Gold is applied as a fluorescent probe. The aptasensor presents the features of high selectivity against adenosine triphosphate and the low detecting limit of concentrations (39.2 nM). In order to verify the validation of experimental procedures and the practical application of the aptasensor, the detection of adenosine triphosphate for human serum samples is performed with satisfactory success. The recovery result with the range of 93.8%–108.1% is desirable and suggests that the designed approach is applicable. The outcomes of the cellular adenosine triphosphate assay manifest that the level of adenosine triphosphate concentrations in cell extracts can be monitored without the interference of other substances in the cells. Subject to its advantageous benefits (cost-effective, easiness, rapidity, and extraordinary selectivity), the designed approach has a promising implication for adenosine triphosphate detection in the research domain of bioanalytical science and biology.

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