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Updated: Feb 11, 2026

Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Sensitive colorimetric assay using insulin G-quadruplex aptamer arrays on DNA nanotubes coupled with magnetic
A Rafati1, A Zarrabi1, S Abediankenari2
1Department of Biotechnology, Faculty of Advanced Science and Technology, University of Isfahan, Isfahan, Iran.
Abstract:
Described here is a methodology for fabrication of a sensitive colorimetric nanoassay for measurement of insulin using G-quadruplex aptamer arrays on DNA nanotubes (DNTs) coupled with magnetic nanoparticles. The spectroscopic findings (e.g. visible spectra, velocity assay and limit of detection determination) indicated a highly sensitive performance of this new nanoassay in comparison to those results obtained from the insulin assay with non-arrayed aptamers. The clinical performance statistics (i.e. paired sample t-test, Bland-Altman plot and scatter diagram) from the newly developed assay and the enzyme-linked immunosorbent assay suggested its reliable precision and its acceptable repeatability for measurement of insulin in human sera. This is, to our knowledge, the first study for the application of magnetic nanoparticle-coupled DNTs for carrying G-quadruplex aptamers for detection of biomolecules (such as insulin) in human serum.
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