测定牙菌斑氟浓度的超微型F^--ISFET电极的研制

Development of a F^--ion sensitive field transistor microelectrode and its preliminary application

目的 :了解局部牙菌斑氟的摄取与代谢情况。方法 :在氢离子敏场效应管 (H+ ISFET)的基础上研制出的一种新型的氟离子敏场效应管传感器 (F- ISFET) ,与毛细管盐桥的Ag/AgCl参比电极复合在一起 ,测定唾液和微量 (微升级 )牙菌斑液中的游离氟浓度 ,进行了性能测试和初步的定量检测。结果 :浓度检测范围 :10 -6～ 10 -1mol/L ,线性检测范围 :10 -6～ 10 -4mol/L ,灵敏度 :3 0～ 5 5mV/pF ,响应时间小于 3 0s ,线性相关系数r2 为 0 .97,回收率为 :94%～ 10 4%。测定唾液样本和菌斑液样本中氟离子浓度分别为 2 .3× 10 -6mol/L和3 .0 6× 10 -5mol/L。结论 :F- ISFET在低浓度测定牙菌斑的氟灵敏度较传统电极高 ,证实了这种F-小电极在口腔医学领域内的可用性。

Objective:To develop a new type of microelectrode used to measure free fluoride in minim solution. Methods:F--ion sensitive field transistor( F--ISFET) microelectrode was developed based on H+-ISFET combined with an Ag/AgCl referential electrode of microtube. The F--ISFET was used to determine the free fluoride ions in saliva and dental plaque fluid in microliter. And its property was investigated. Results:The test limit of F--ISFET was 10 -6 mol/L-10 -1mol/L, the linear test limit was 10 -6mol/L-10 -4mol/L, the sensitivity was 30-55 mV/pF, the responding time was less than 30 seconds, r2 was 0.97, the reclamation was 94%-104%. Conclusion:F--ISFET can be used to measure free fluoride ions in dental plaque.