Belt-like X-doped VO2(M) (X=W, Mo, Sn or Fe) with rectangular cross sections were successfully synthesized by a facile one-pot hydrothermal approach. The as-obtained samples were characterized by XRD, XPS, SEM, DSC and variable-temperature IR. The results showed that the additives W, Mo, Sn and Fe could promote the formation of VO2(M) under hydrothermal conditions. The additives had little influence on the morphology of doped VO2(M), but they were the key factor for the synthesis of VO2(M). The W and Mo atoms could effectively reduce the Tc of VO2(M), while Sn and Fe atoms had little influence on Tc. Furthermore, it was found that the as-obtained doped VO2(M) possessed prominent thermochromic properties and optical switching characters.Graphical abstractThe additives W, Mo, Sn and Fe can promote the formation of VO2(M) under the hydrothermal conditions.Highlights► one-pot hydrothermal route was developed to fabricate belt-like doped VO2(M). ► Additives W, Mo, Sn and Fe can promote the formation of VO2(M). ► Additives have little influence on the morphology of doped VO2(M). ► W and Mo can reduce Tc of VO2(M), while Sn and Fe have little influence on Tc. ► Doped VO2(M) has thermochromic characters and optical switching properties.

•A QCM and SERS combination setup was designed to monitor the thrombin aptamer binding kinetics.•A sandwich-structural sensing interface was assembled, and the process was monitored by QCM.•The sensing interface enables QCM response and SERS signals for low concentration thrombin.We reported quartz crystal microbalance (QCM) and surface enhancement Raman spectroscopy (SERS) combination to detect thrombin for the first time. 1,6-hexanedithiol (HDT) monolayer was assembled on the Au electrode of crystal ship and 20 nm Au NPs were assembled on this layer with stable Au-S linkage to form a two-dimensional nanoarray interface. Aptamers modified by thiol groups were assembled on this interface for capturing thrombin in succession. In the QCM detection process, the introduction of 40 nm aptamer-functionalized Au NPs amplify the frequency signal significantly. The thrombin detection limit reduced from 1 μM to 0.1 μM, and a good linear correlation was obtained between the change of frequency and the concentration of the thrombin in a range of 0.1 to 1.0 μM. Meanwhile, with the modification of Raman reporter 4-mercaptobenzoic acid onto the surface of 40 nm Au NPs, SERS signals of thrombin were obtained simultaneously. This assay also exhibited excellent selectivity both in QCM and SERS detection of thrombin.