PdCl₂、Hb敏化的纳米SiO₂膜CO传感器的研究

【作者】 汤平；

【导师】 司士辉；

【作者基本信息】 中南大学 ， 分析化学， 2004， 硕士

【摘要】 用溶胶—凝胶盐酸催化法成功制备纳米SiO₂溶胶，并用浸渍法在经过超声的载玻片上制得SiO₂薄膜。将薄膜浸入氯化钯、氯化铜混合溶液，匀速提拉，干燥后制得敏感膜。利用钯盐与一氧化碳反应，生成钯单质，引起吸光度变化。实验中在510nm波长下测量吸光度的变化，发现在20min反应时间内，吸光度的变化随着CO气体浓度的增加而增大。实验表明基于3倍信噪比（3S／N）可估算，该敏感膜检测极限为1.8×10^-5（体积分数，下同），完全可用于6×10^-4CO气体临界报警浓度的检测。而氯化铜能在空气中将钯氧化成钯盐，使该敏感膜可反复使用。用一些家庭常见的易挥发有机溶剂所做的干扰实验表明此敏感膜受干扰程度小。为了提高传感器的响应灵敏度，还把3～4片同规格的膜排成阵列式进行了讨论。 此外还研制了血红蛋白的光学型CO传感器。用纳米SiO₂包埋Hb作成CO敏感膜，同时结合光学信号转换器，利用Hb与CO反应后吸收光谱的变化来检测CO浓度。实验证明这种传感器具有灵敏度高、响应速度快、选择性好等优点。本研究对提取和保存血红蛋白的方法进行了改进，Hb提取液的浓度为0.274g／ml，确定传感器的工作波长620nm，探讨了血红蛋白固定化方法。更多还原

【Abstract】 Silicon dioxide thin film prepared by a sol-gel technique, was used as a sensing layer after treatment of solution of palladium chloride and copper chloride,because the reduction of Pd2+ ions by CO gas resulted in change of the layer absorbance.With photocurrent measurement at 510nm wavelength, an obvious photocurrent response was observed for 6 10-1 CO gas in comparison with the blank sample and it can be expected that the present sensing layer can detect the concentration of CO gas below 1.8 X 10~5 based on three times of Signal-to-Noise.The sensing layer could be recovered through copper chloride oxidizing Pd. Interferential experiments showed that no obvious response was found for the organic odor in living surroundings. For the improvement of the performence of CO sensors, It was discussed that 3 ~4 pieces of identical standard film were arrayed.Moreover,the optical CO sensor based on sensing layer of hemoglobin/nano-sized SiO2 particles was explored.The sensing element was prepared by embeding hemoglobin in nano-SiO2 film. Using the optical transducer, the concentration of CO was determined based on the change of the spectrum of Hb. Experiment results showed that the present CO sensor possesses high sensitivity and selectivity, fast response, etc. In this study, the method for purification and storage of Hb was improved, and the concentration of the Hb extract was 0.274g/ml.The working wavelengh of the sensor was 620nm, which was optimized by experiments, and the response of Hb to CO was investigated.Finally.the immobilization of Hb was also dissussed.更多还原