A Three-Dimensional AgNPs/TiO 2 /Ti 3 C 2 Tx Composite for Label-Free Thrombin Aptamer Sensor

A one-step hydrothermal method was employed to synthesize a three-dimensional (3D) AgNPs/TiO 2 /Ti 3 C 2 Tx composite. Hydrothermal conditions were used to promote the growth of TiO 2 nanorods on the Ti 3 C 2 Tx sheet, resulting in the formation of a three-dimensional composite nanomaterial. Glutamic acid served as both a reducing agent and a stabilizer to load Ag nanoparticles (AgNPs) onto the 3D composite nanomaterial. The structure of the composite material provided a large accessible surface area, facilitating the anchoring of Ag NPs. Thrombin aptamers were then linked to Ag NPs through Ag-S bonds, establishing a sensitive and label-free aptasensor for thrombin detection. The proposed aptasensor demonstrated excellent electrochemical performance, with a broad linearity range of 5.0 fM to 500 nM and a relatively low detection limit of 2.0 fM (S/N = 3). These findings indicate the potential of Ag NPs/TiO 2 /Ti 3 C 2 Tx in the development of promising electrochemical biosensors. A one-step hydrothermal method was employed to synthesize a three-dimensional AgNPs/TiO 2 /Ti 3 C 2 Tx composite. AgNPs/TiO 2 /Ti 3 C 2 Tx composite was utilized for fabrication of the label-free thrombin aptamer sensor. TiO 2 nanorods and AgNPs were grown in vivo on the Ti 3 C 2 Tx sheet.