Colloidal Nanogold-Based Immunochromatographic Strip Test for the Detection of Digoxin Toxicity

Abstract

Digoxin is widely used as a cardiac glycoside drug in the treatment of various heart conditions. Because it is a toxic drug, it should be regularly monitored in the serum of patients under treatment. In this study, colloidal nanogold is synthesized and the preparation of nanogold-labeled monoclonal antibody probe to digoxin is described under optimal conditions. In addition, an immunochromatographic (IC) method for digoxin analysis employing nanogold-labeled probe is developed. With this technique, it requires only 5 min to complete the quantitative detection of digoxin. The detection time is decreased 20-30 times in comparison to radioimmunoassay (RIA). The sensitivity to digoxin was about 2 ng/ml by naked eye, which is within the therapeutic and toxic ranges of digoxin. The results of serum samples obtained by IC strip were in agreement with those obtained by RIA. The IC strip was sufficiently sensitive and accurate to be used for the rapid detection of digoxin in serum samples.

Development of Medical Devices Based on Protein Marker for Animal and Human Diseases

“…The size of the gold particles varies between 2 and 150 nm, but generally 15-25 nm particles were used (Zhao et al, 2008;Omidfar et al, 2010). The advantages of gold particles are being stable, easy to use and have convenient surfaces to accelerate the antibody-antigen recognitions, which increases the immunoassay signals and allows a smooth flow through the membrane (Aulanni"am, 2013).…”

A new gold nanoparticle based rapid immunochromatographic assay for screening EBV-VCA specific IgA in nasopharyngeal carcinomas

“…Once the color in the solution changed from light yellow to purple-red the solution was cooled down. The yielded gold colloid was stored at 4 8C in a dark-colored glass bottle after adjusting the pH to 8.5 by 0.01 M potassium carbonate, and adding sodium azide (0.01% w/v) (Omidfar et al, 2010(Omidfar et al, , 2012a.…”

“…For example, the ICG strip test contains GNPs with the diameter of 20 nm for developing color signal. The size of the GNPs can affect the results; if GNPs with a diameter larger than 60-70 nm is used there is a risk for self-aggregation after storage at 4 8C (Omidfar et al, 2010). On the other hand, GNPs with lower than 15 nm diameter would generate a very weak signal.…”

“…The intra particles' electrostatic repulsion and London-van der Waals's attraction equilibrium contributes to the formation of the GNPs. Immunoglobulins can be directly attached on the surface of GNPs by the non-covalent reactions during the conjugation (Omidfar et al, 2010). The efficacy of the conjugate is strongly associated with the size and quality of the colloidal gold NPs (Gui et al, 2008;Omidfar et al, 2011).…”

Development of an immunochromatographic assay based on carbon nanoparticles for the determination of the phytoregulator forchlorfenuron

“…Accordingly, the development of quantitative immunochromatographic tests is gaining increasing attention. Successful examples have been described for the analysis of proteins (Kim et al, 2006;van Amerongen et al, 1994;Wei et al, 2011), nucleic acids (Blažková et al, 2011;He et al, 2011;Noguera et al, 2011;van Amerongen and Koets, 2005), and small organic molecules (Blažková et al, 2010;Campbell et al, 2007;Hua et al, 2010;Kaur et al, 2007;Omidfar et al, 2010;Mirasoli et al, 2012;O'Keeffe et al, 2003;Wang et al, 2011;Xie et al, 2009).…”