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Two-dimensional materials have attracted great interest in humidity sensing due to their excellent sensitivity and response time. Herein, we propose a humidity sensor consisting of MXene and single-walled carbon nanotubes (SWCNTs), using the Marangoni effect to self-assemble two-dimensional materials on the liquid surface, and then preparing them on the interdigital substrate through the layer-by-layer dip-coating method. Due to the expanded interlayer spacing of MXene and more exposed hydrogen active sites provided by SWCNTs, the sensor showed an excellent dynamic property with the response and recovery time of 2 s and 1.75 s Besides, the sensitivity is 0.53 pF/% RH (10–60% RH) and 7.6 pF/% RH (60–90% RH), the maximum humidity hysteresis is 6% of full scale (60% RH), and the reproducibility is ＞200cycles. Then, a flexible humidity breathing detection system has been developed based-on the sensor. Result demonstrated that it can detect human respiration and be successfully used to distinguish different human respiratory patterns. This work not only optimizes the dynamic property of sensors, but also provides a solution for the production of high-performance flexible humidity monitoring systems on this basis. • A low-cost manufacturing preparation method for MXene -SWCNTs humidity sensors has been proposed. • SWCNTs are doped in MXene to expand the interlayer spacing, resulting in a response and recovery time of 2/1.75s. • Making a wearable testing system by mounting sensors on flexible circuit boards and it can detect human respiration. [ABSTRACT FROM AUTHOR]

Teramethylpyrazine (TMP) is a pyrazine alkaloid with a variety of pharmacological effects and widely used in clinical practice. In this study,Monascusstrain M-3 with high TMP and low citrinin productions was screened from red yeast rice collected from different areas of Fujian province in China.Monascusstrain M-3 was further identified through molecular biological methods based on the sequencing of different gene regions. Results showed that primer set of β-tubulin-F/β-tubulin-R targeting the β-tubulin gene was more suitable for the identification ofMonascusstrain M-3. Based on comparative analysis of the results obtained by different primer sets,Monacusstrain M-3 was finally identified asMonascus purpureus. Then, the composition of culture medium and liquid state fermentation conditions ofMonacusstrain M-3 were optimized by single-factor experiment and central composite design of response surface methodology, with the purpose of optimizing the TMP productions. The optimum composition of culture medium and liquid state fermentation conditions are as follows: starch 5.1%, peptone 3.51%, Mg2SO40.1%, NaNO30.2%, KH2PO40.25%, fermentation temperature of 28.23 °C, fermentation time of 9 d, shaker speed of 180 r/min, inoculum size of 7.21% and loading volume of 100 mL/250 mL triangular flask. Under the optimum composition of culture medium and liquid state fermentation conditions, the TMP production ofMonacusstrain M-3 can reach 13.49 µg/mL. This study is expected to provide a new approach of TMP production through biosynthesis byMonascusstrain, and promote the further development of functional foods or medicines fromMonascusfermentation products. [ABSTRACT FROM AUTHOR]