A smartphone-based ultrasensitive colorimetric aptasensing platform for serine protease thrombin detection

Abstract

The first smartphone-based portable and ultrasensitive colorimetric aptasensor was reported for rapid and naked-eye detection of thrombin. The cysteamine-capped gold nanoparticles (CyA-AuNPs) along with thrombin-specific aptamer were employed for thrombin detection, which was based on the color change property of AuNPs from red to blue depending on the thrombin concentration in a sample solution. The quantitative detection was performed by capturing the image of sample solution in reusable eppendorfs and their color intensity (blue/red) was noted using Image J software. Smartphone-based aptasensing platform acquired a linear detection range for thrombin from 0.5 to 4.0 nM with a limit of detection (LOD) of 0.1595 nM, 0.2042 nM, and 0.2058 nM in de-ionized (DI) water, human serum, and human plasma, respectively within 10 min. The developed aptasensor showed high selectivity for thrombin in the presence of other interfering moieties. All the obtained results from smartphone-based analysis were validated by comparing them with UV–Visible analysis and analogous findings were found. The proposed smartphone-based aptasensing platform eliminates the usage of large instruments by providing the simple, economical, and rapid detection of thrombin. Correspondingly, the proposed promising smartphone-based detection method with mobility, lightweight, and flexibility can replace sophisticated instruments.