An Electrochemical Aptamer-Based Assay for Femtomolar Determination of Insulin Using a Screen Printed Electrode Modified With Mesoporous Carbon and 1,3,6,8-Pyrenetetrasulfonate Publisher Pubmed



Amouzadeh Tabrizi M^{1, 2} ; Shamsipur M³ ; Saber R^{2, 4} ; Sarkar S^{2, 5} ; Besharati M^{6, 7} Show Affiliations
Source: Microchimica Acta Published:2018

Abstract

The authors describe an electrochemical method for aptamer-based determination of insulin at femtomolar concentrations. The surface of a screen printed electrode was modified with ordered mesoporous carbon that was chemically modified with 1,3,6,8-pyrenetetrasulfonate (TPS). The amino-terminated aptamer was then covalently linked to TPS via reactive sulfonyl chloride groups. Subsequently, the redox probe Methylene Blue (MB) was interacted into the aptamer. The MB-modified binds to insulin and this results in the release of MB and a decreased signal as obtained by differential pulse voltammetry, best at a working voltage of −0.3 V (versus silver pseudo-reference electrode). Insulin can be quantified by this method in the 1.0 f. to 10.0 pM concentration range, with a 0.18 f. limit of detection (at 3σ/slope). The assay was applied to the determination of insulin in spiked human serum samples. The method is highly sensitive, selective, stable, and has a wide analytical range.[Figure not available: see fulltext.]. © 2017, Springer-Verlag GmbH Austria, part of Springer Nature.