Optimized Vacuum-Sputtered Gold Nanoparticle-Modified Titanium Dioxide Nanotubes for Ultrasensitive Myocardial Infarction Multi-Biomarker Detection.

Abstract

Myocardial infarction, a sudden reduction in blood flow to the heart, requires rapid and sensitive detection of biomarkers reflecting different stages of cardiac injury and plaque destabilization. Herein, a universal electrochemical biosensing platform based on gold nanoparticle-modified titanium dioxide nanotubes (AuNPs/TNTs) was developed for the detection of cardiac troponin T (cTnT), heart-type fatty acid-binding protein (H-FABP), and pregnancy-associated plasma protein A (PAPP-A). Titanium dioxide nanotubes with a diameter of 50 ± 5 nm and a length of 1000 ± 100 nm, previously optimized for electrochemical and adsorption properties, were modified with AuNPs by vacuum sputtering at 20 mA for 10, 20, and 40 s. The influence of nanoparticle deposition on the morphology, phase composition, surface chemistry, wettability, and electrochemical properties of AuNPs/TNTs was systematically investigated. The AuNPs/TNTs sample prepared by Au sputtering for 10 s exhibited the most favorable physicochemical properties for biosensing applications. After nanocomposite functionalization, the platform enabled impedimetric detection of cTnT, H-FABP, and PAPP-A in clinically relevant concentration ranges. The obtained limits of detection for cTnT, H-FABP, and PAPP-A were 0.01, 0.23, and 0.008 ng/mL, respectively. To the best of the authors' knowledge, this is the first AuNPs/TNTs-based electrochemical platform for the detection of cTnT, H-FABP, and PAPP-A. In addition, no AuNPs/TNTs electrochemical biosensor for PAPP-A determination has been reported to date.

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