Gallic acid (GA) is a phenolic compound found in almost all plants and has been reported to possess powerful health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, and anti-diabetic properties. However, GA suffers a short half-life when administered in vivo. Recent studies have employed graphene oxide (GO), a biocompatible and cost-effective graphene derivative, as a nanocarrier for GA. However, the toxicity effect of this formulated nano-compound has not been fully studied. Thus, the present study aims to evaluate the toxicity and teratogenicity of GA loaded GO (GAGO) against zebrafish embryogenesis to further advance the development of GA as a therapeutic agent. GAGO was exposed to zebrafish embryos (n ≥ 10; 24hr post fertilization (hpf)) at different concentrations (0-500 μg/ml). The development of zebrafish was observed and recorded twice daily for four days. The toxicity of pure GO and GA was also observed at similar concentrations. Distilled water was used as control throughout the experiment. A significantly high mortality rate, delayed hatching rate and low heartbeat were recorded in embryos exposed to GO at concentrations of ≥ 150 μg/ml at 48 hr (p
Room temperature carbon nanotubes (CNT)-based gas sensor was utilised in detection of methane, CH4 gas. The CNT was functionalized with amide group via Fischer esterification process and labelled as CNT-Amide. Silicon dioxide, SiO2 substrate with interdigitated prepatterned gold electrodes were employed as transducers and drop casting technique was used to deposit the multi walled-CNT samples. The electrical properties of the functionalized CNT samples in the exposure of CH4 gas are studied by recorded the changes of resistance using digital multimeter. Concentration of CH4 gas was varied from 1250 ppm to 10 000 ppm. The changes of electrical resistance of CNT-Amide increases with the concentration of tested gas. Sensor response of functionalized CNT are improved more than 10% as compared to pristine CNT. The sensitivity of CNT-Amide also better than CNT-Carboxyl due to the presence of nitrogen element in amide functional group which chemically active to react with CH4 gas. Additionally, fast response of CNT-Amide towards CH4 gas suggested that the functional group enhanced the rate of gas adsorption on sensing layer.
Multi walled-carbon nanotubes (CNT) functionalized with ester was used for detecting methane, CH4 gas at room temperature. Quartz substrate with interdigitated prepatterned gold electrodes was employed as transducers and drop casting method was used to deposit the CNT samples. The electrical properties of the functionalized CNT samples in the presence of CH4 gas were studied and the changes of resistance were recorded using digital multimeter. Concentration of CH4 gas was varied from 0.125 % to 1.0 %. The resistance variation of functionalized CNT increased with the concentration of tested gas. Sensor response of functionalized CNT was improved more than 10 % as compared to pristine CNT. CNT-Ester gives the higher sensitivity due to the presence of ester functional group which act as active site to react with CH4 gas. The fast response of functionalized CNT towards CH4 gas suggested that the functional group enhanced the rate of gas adsorption on sensing layer