Development of nano-scale sensing device using dielectrophoresis

(A)利用液相还原反应将Pd纳米粒子功能化dep制备的碳纳米管气体传感器及其在氢气传感器上的应用(1)将保留碳纳米管的微电极与石墨棒一起浸入醋酸钯溶液中。在微电极（阴极）和石墨棒（阳极）之间施加直流电压，使醋酸钯还原并在碳纳米管表面电沉积催化钯。(2)在室温下，碳纳米管传感器对空气中浓度在0.01% ~ 1%范围内的氢气有可逆响应。(1)我们提出了一种基于碳纳米管气体传感器和微加热器的新型细菌传感装置。利用空气中的微加热器对细菌进行加热，使细菌的有机组分氧化反应生成氨（NH3）气体。(2)利用碳纳米管气体传感器检测由此产生的NH3气体，碳纳米管气体传感器采用介质电泳法制备，与微加热器一起安装在一个小室中。该装置可检测和定量107种细菌（大肠杆菌）。

(A) Functionalization of DEP-fabricated CNT gas sensor with Pd nanoparticles using liquid-phase reducing reactions and its application to a hydrogen gas sensor(1) The CNT-retaining microelectrode was immersed in a palladium acetate solution together with a graphite rod. DC voltage was applied between the microelectrode (cathode) and the graphite rod (anode) so that palladium acetate could be reduced and catalytic Pd could be electrodeposited on the CNT surface.(2) The CNT sensor could reversibly respond to hydrogen gas in the air in the range of 0.01% - 1% concentration at room temperature.(B) Bacterial detection using a carbon nanotube gas sensor coupled with a microheater for ammonia synthesis by aerobic oxidization(1) We proposed a new bacteria sensing device, which is based on a CNT gas sensor and micro heater. Bacteria were heated by the micro heater in air so that ammonia (NH3) gas can be generated by oxidation reaction of organic components of bacteria.(2) Thus generated NH3 gas was detected by using the CNT gas sensor, which was fabricated by dielectrophoresis and installed in a small chamber together with the micro heater. The proposed device could detect and quantify 107 bacteria (Escherichia coli).