Diagnostics

2515 KiB

Open AccessArticle

Screen Printed Carbon Electrode Based Electrochemical Immunosensor for the Detection of Dengue NS1 Antigen

by Om Parkash, Chan Yean Yean and Rafidah Hanim Shueb

Diagnostics 2014, 4(4), 165-180; https://doi.org/10.3390/diagnostics4040165 - 20 Nov 2014

Cited by 46 | Viewed by 12361

An electrochemical immunosensor modified with the streptavidin/biotin system on screen printed carbon electrodes (SPCEs) for the detection of the dengue NS1 antigen was developed in this study. Monoclonal anti-NS1 capture antibody was immobilized on streptavidin-modified SPCEs to increase the sensitivity of the assay. Subsequently, a direct sandwich enzyme linked immunosorbent assay (ELISA) format was developed and optimized. An anti-NS1 detection antibody conjugated with horseradish peroxidase enzyme (HRP) and 3,3,5,5'-tetramethybezidine dihydrochloride (TMB/H₂O₂) was used as an enzyme mediator. Electrochemical detection was conducted using the chronoamperometric technique, and electrochemical responses were generated at −200 mV reduction potential. The calibration curve of the immunosensor showed a linear response between 0.5 µg/mL and 2 µg/mL and a detection limit of 0.03 µg/mL. Incorporation of a streptavidin/biotin system resulted in a well-oriented antibody immobilization of the capture antibody and consequently enhanced the sensitivity of the assay. In conclusion, this immunosensor is a promising technology for the rapid and convenient detection of acute dengue infection in real serum samples. Full article

(This article belongs to the Special Issue In Vitro Diagnostics)

► Show Figures

Figure 1

683 KiB

Open AccessReview

Current Challenges Towards the Development of a Blood Test for Parkinson’s Disease

by Jose A. Santiago and Judith A. Potashkin

Diagnostics 2014, 4(4), 153-164; https://doi.org/10.3390/diagnostics4040153 - 22 Oct 2014

Cited by 10 | Viewed by 6627

Abstract

Parkinson’ disease (PD) is the second most prevalent neurodegenerative disease worldwide. To date, there is no disease-modifying agent, and current medical treatment only provides symptomatic benefits. Early diagnosis of PD would be useful in clinical practice to identify patients for clinical trials, test potential drugs and neuroprotective agents and track their therapeutic effect. Considerable progress has been made in the discovery and validation of diagnostic biomarkers for PD. In particular, blood-based biomarkers have shown promise in identifying PD patients in samples from independent clinical trials. Evaluation of these biomarkers in de novo patients and individuals at risk for PD remains a top priority. Here, we review the current advances and challenges toward the clinical translation of these biomarkers into a blood-based test for PD. Full article

(This article belongs to the Special Issue Biomarkers in Blood)

1318 KiB

Open AccessArticle

Spectro-Fluor™ Technology for Reliable Detection of Proteins and Biomarkers of Disease: A Pioneered Research Study

by Farid Menaa, Bouzid Menaa and Olga N. Sharts

Diagnostics 2014, 4(4), 140-152; https://doi.org/10.3390/diagnostics4040140 - 29 Sep 2014

Cited by 4 | Viewed by 7644

Abstract

Quantitative and qualitative characterization of fluorinated molecules represents an important task. Fluorine-based medicinal chemistry is a fast-growing research area due to the positive impact of fluorine in drug discovery, and clinical and molecular imaging (e.g., magnetic resonance imaging, positron emission tomography). Common detection methods include fluorinated-based labelling using radioactive isotopes or fluorescent dyes. Nevertheless, these molecular imaging methods can be harmful for health due to the potential instability of fluorochromes and cytoxicity of radioisotopes. Therefore, these methods often require expensive precautionary measures. In this context, we have developed, validated and patented carbon-fluorine spectroscopy (CFS™), recently renamed Spectro-Fluor™ technology, which among a non-competitive family of in-house made devices called PLIRFA™ (Pulsed Laser Isochronic Raman and Fluorescence Apparatus™), allows reliable detection of Carbon-Fluorine (C-F) bonds. C-F bonds are known to be stable and safe labels once incorporated to any type of molecules, cells, compounds or (nano-) materials. In this pioneered research study, we used Spectro-Fluor™ to assess biomarkers. As a proof-of-principle experiment, we have established a three-step protocol intended to rapid protein detection, which simply consisted of: (i) incorporating a sufficient concentration of an aromatic amino-acid (fluorinated versus non-fluorinated) into cultured cells; (ii) simultaneously isolating the fluorinated protein of interest and the non-fluorinated form of the protein (control) by immune-precipitation; (iii) comparatively analyzing the respective spectrum obtained for the two protein forms by Spectro-Fluor™. Thereby, we were able to differentiate, from colon cancer cells HCT-116, the fluorinated and non-fluorinated forms of p21, a key transcriptional factor and downstream target of p53, the so-called “guardian of the genome”. Taken together, our data again demonstrates the beneficial alternative use of Spectro-Fluor™, which once combined with an innovative methodology permits one to quickly, reliably, safely and cost-effectively detect physiological or pathological proteins in cells. Full article

(This article belongs to the Special Issue In Vitro Diagnostics)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Diagnostics, Volume 4, Issue 4 (December 2014) – 3 articles , Pages 140-180

Further Information

Guidelines

MDPI Initiatives

Follow MDPI