This paper demonstrated a hybrid composite of tin oxide–reduced graphene oxide (rGO) for ppm-level detection of ethanol vapour. A facile and low-cost method of hydrothermal synthesis was used to construct the SnO2–rGO hybrid film on a PCB substrate with coil-like interdigital microelectrodes. The presence of small-sized SnO2 nanocrystals on rGO sheets was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), an X-ray diffractometer (XRD) and Brunauer–Emmett–Teller (BET) measurements. The sensing properties of the SnO2–rGO hybrid film sensor, including the sensitivity, response–recovery times and repeatability, were investigated by exposing it to various concentrations of ethanol gas varying from 1 ppm to 100 ppm at room temperature. As a result, the presented sensor exhibited a low detection limit of 1 ppm at room temperature, as well as a fast response–recovery time and good repeatability, which outstripped that of pure rGO film sensors. Finally, the possible mechanism of ethanol gas-sensing for the above presented sensor was discussed in detail.
1 November 2014 in Chemico-Biological Interactions
Objectives: Chlorogenic acid (CGA) is one of the most widely consumed polyphenols in diets and is recognized to be a natural hepatoprotective agent. Here, we evaluated the protective effect and the potential mechanism of CGA against ɑ-naphthylisothiocyanate (ANIT)-induced cholestasis and liver injury. Methods: Twenty-five male 129/Sv mice were administered with CGA, and ANIT challenge was performed at 75 mg/kg on the 4th day. Blood was collected and subjected to biochemical analysis; the liver tissues were examined using histopathological analysis and signalling pathways. Key findings: Chlorogenic acid almost totally attenuated the ANIT-induced liver damage and cholestasis, compared with the ANIT group. Dose of 50 mg/kg of CGA significantly prevented ANIT-induced changes in serum levels of alanine aminotransferase, alkaline phosphatases, total bile acid, direct bilirubin, indirect bilirubin (5.3-, 6.3-, 18.8-, 158-, 41.4-fold, P<0.001) and aspartate aminotransferase (4.6-fold, P<0.01). Expressions of the altered bile acid metabolism and transport-related genes were normalized by cotreatment with CGA. The expressions of interleukin 6, tumour necrosis factor-α and suppressor of cytokine signalling 3 were found to be significantly decreased (1.2-fold, ns; 11.0-fold, P<0.01; 4.4-fold, P<0.05) in the CGA/ANIT group. Western blot revealed that CGA inhibited the activation and expression of signal transducer and activator of transcription 3 and NFκB. Conclusions: These data suggest that CGA inhibits both ANIT-induced intrahepatic cholestasis and the liver injury. This protective effect involves down-regulation of STAT3 and NFκB signalling.
1 January 2017 in Environmental Toxicology and Pharmacology