Ultrasensitive detection of thrombin based on MoS_2-aptamer biosensors by resonance light scattering technique

摘要

Graphical abstractIn this design, DNA1, a label-free ssDNA, is composed of thrombin aptamer (TBA) and the random DNA (rDNA). In the absence of thrombin, DNA1 was adsorbed on the surface of MoS2to form a stable DNA1-MoS2complex which produced a weak RLS signal. In the presence of thrombin, the thrombin aptamer can transform into a G-quartet structure and combine with thrombin, and the rDNA will still dissociate in solution. Once MoS2is introduced, the free rDNA can be adsorbed on the surface of MoS2to form a stable DNA1-thrombin-MoS2complex, which increases RLS signals.Display OmittedHighlights•A label-free RLS sensor based on MoS2is developed for ultrasensitive detection of thrombin.•The preparation process is greatly simplified without cumbersome substrate material.•The sensor possesses highly selective and ultrasensitive for thrombin detection.AbstractRapid and sensitive detection of thrombin has very important significance in biomedical and bioanalytical applications. In this study, a label-free and simple resonance light scattering (RLS) sensor based on MoS2nanomaterial is developed for ultrasensitive and highly selective detection of thrombin. In the presence of thrombin, the thrombin aptamer can transform into a G-quartet structure and combine with thrombin, resulting in dissociation of the random DNA (rDNA) in the solution. Once MoS2is introduced, the free rDNA can be adsorbed on the surface of MoS2to form a stable DNA1–thrombin–MoS2complex, which increases RLS signals. The sensor shows two linear ranges of 10 pM to 500 pM and 1nM to 60nM, and a detection limit of 0:71 pMfor detection of thrombin. Our sensor is a promising tool for clinical diagnosis of thrombin in human serum. Moreover, this work can offer new opportunities for the development of convenient sensor for detecting other proteins.