聚苯胺修饰钨丝针型复合微pH传感器的研究及在水果测试中的应用

Investigations on Polyaniline Film Modified Tungsten Filament as Composite Micro Needle-Concentric pH Sensor and Its Applications to the Fruit Internal pH Detection

由电聚合法将聚苯胺修饰的钨丝电极作为pH敏感电极，把Ag－AgCl体系填入针型塑料管内构成参比电极，把经聚苯胺修饰的钨丝电极安置入该针型参比电极内构成复合针型微pH传感器，在pH2～12范围内，该传感器呈现Nernst响应，斜率为55mV／pH，响应时间＜1min，该传感器成功地应用于水果内微区pH的测定。

A tungsten filament electrode modified with polyaniline by electro-polymerization was prepared to work as pH-sensitive electrode.A plastics needle filled with Ag/Agcl redox system was used as rettrence electrode.A micro needleconcentric pH sensor was constructed by inseFting the polyaniline-modified tungsten filament electrode in the needle reference electrode obtained above.The sensor exhibited a linear response in the range 2~12 pH.with a Nernst response slope (55mV/pH) and a response time of less than 1 min .The results obtained from the sensor were in good agreement with those from the glass pH electrode.The sensor has been successfully employed to determine pH in micro region of fruit.