This research demonstrated the electrochemical modification of low-cost titanium (Ti) metal substrate with gold nanoparticles (AuNPs) for the aptamer-based detection of cardiac troponin I (cTnI). AuNPs were deposited onto Ti sheets by the potential-step deposition method with high density and homogeneity as well as good crystallinity. It was then applied as a transducer to immobilize a thiol-functionalized DNA aptamer via the self-assembled monolayer mechanism for the specific binding of cTnI. This was verified through electrochemical and morphological analyses. The aptasensor could detect cTnI in a linear range of 1-1100 pM with a detection limit of ca. 0.18 pM. The aptasensor showed high sensitivity and specificity to cTnI over other interfering compounds with good recoveries in the diluted human serum samples.
Keywords: Aptamer; Cardiac troponin I; Differential pulse voltammetry; Gold nanoparticles; Label-free; Ti foil.
Copyright © 2018 Elsevier B.V. All rights reserved.