基于Y形光纤的便携式免疫荧光定量检测系统

Portable immunofluorescence detection system based on Y-shape optical fiber

为了满足POCT仪器体积小、操作简单、携带方便、结果报告及时化的检验模式新要求,设计并开发一款基于Y形光纤的便携式免疫荧光定量检测仪。该设备以恒流源驱动激光二极管作为激发光源,Y形光纤作为光信号传输介质,光电二极管作为荧光信号接收传感器,替代复杂庞大的传统共聚焦光学系统,使光路设计及信号采集模块小型化;设计Sallen-Key拓扑结构的二阶有源低通滤波器对信号进行放大滤波处理,以减少杂波干扰,提高系统灵敏度;采用STM32F103微处理器为主控芯片,控制步进电机驱动机械扫描模块、光电信息采集模块、数据处理及显示模块完成免疫层析试纸条的荧光值定量检测。AD采集精度实验显示,该系统的AD采样偏差为10μV,标准差为1.91E-06;实测荧光微球实验表明,荧光微球稀释倍数和荧光强度信号之间的乘幂关系良好,相关系数为0.99,该系统检测灵敏度高,重复性好。

To meet the requirements of portable,operated conveniently and test rapidly of novel POCT instruments,a immunofluorescence detection system based on Y-shape fiber was introduced.The confocal optical path in conventional immunofluorescence detection system was substituted with Y-shape optical fiber because of its bulky volumes and complex structures.The system used a laser diode for excitation source drived by constant-current source and a photodiode for detection of fluorescent signals.To reduce noise figure and improve sensitivity,the Sallen-Key topology with the Butterworth response was used to design the filtering-amplifying circuit.The functions of stepper motor control,fluorescence signal processing,and result display were realized by control system with the core of STM32F103 microprocessor.The AD accuracy experiment shows that the sampling offset is 10μV,standard deviation is 1.91E-06.There existes very significant power correlation between the diluting factor and fluorescence intensity signal(R=0.99),the detection system has advantages of higher sensitivity and good repeatability.