Solid-phase colorimetric apta-biosensor for thrombin detection

• Published in: Thin solid films 2019-09, Vol.686, p.137428, Article 137428
• Main Authors: Lee, Wonjung, Shaban, Samy M., Pyun, Do Gi, Kim, Dong-Hwan
• Format: Article
• Language: English
• Subjects: Aptamer; Colorimetric biosensor; Gold; Nanoparticles; Solid-phase detection; Thrombin
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2019.137428

Herein, we developed a solid-phase colorimetric apta-biosensor for thrombin detection. Aggregation of gold nanoparticles (AuNPs) deposited on a 3-aminopropyltriethoxysilane (APTES) substrate was utilized to form the colorimetric sensor. The APTES-coated substrate with primary aptamer (TBA1)-conjugated AuNPs (AuNP-TBA1) was used to construct the solid-phase sensing platform, where an enhancement of the localized surface plasmon resonance due to the AuNPs was observed upon incubation with a target molecule (thrombin). The introduction of secondary aptamer-conjugated AuNPs (AuNP-TBA2) induced plasmonic coupling of the AuNPs, resulting in significantly enhanced spectral signals and peak shifts and visually detectable color changes. This sensing platform not only includes several advantages, such as simplicity and rapid detection, but also allows naked-eye detection sensitivity at 3 μg/mL with no analytical equipment and a limit of detection of 1.33 μg/mL using UV–vis. •Development of a colorimetric dual-aptamer sandwich solid sensor for thrombin detection.•Thrombin visual detection is based on induced gold nanoparticles (AuNPs) aggregation.•The secondary aptamer-conjugated AuNPs induce plasmonic coupling of the AuNPs.•The sensing platform characteristics are simplicity and rapid naked-eye detection.