一种数字免疫检测系统的设计与性能测试

Design and evaluation of digital immunoassay system

目的:设计一种数字免疫检测系统,以提高现场条件下病原微生物检测的灵敏度。方法:该系统包括数字免疫流体芯片和成像检测系统2个部分。其中数字免疫流体芯片设计时增加试剂检测体系,由石英玻璃(上层)、有机玻璃(中层)和石英玻璃(底层)3层组成;成像检测系统由中继镜头、光源、摄像机、分光片、滤光片等组成。通过MATLAB编程编写信号处理算法,以实现对荧光信号的准确提取。以伤寒沙门氏菌作为检测样本,进行系统性能测试与评价。结果:该系统能够实现对伤寒沙门氏菌的高灵敏度检测,检测时间为30 min,检测灵敏度达到3.5×10^(3) cfu/mL。结论:该系统操作简便,简化了样本处理流程,降低了样本检测浓度下限,可满足现场条件下病原微生物快速、准确检测的需求。

Objective To design a digital immunoassay system to enable high sensitivity detection of microorganisms in field conditions.Methods A digital immunoassay system was designed composed of two parts:a digital immunofluidic chip and an imaging detection system.The digital immunofluidic chip was embedded with a reagent detection system,consisting of 3 layers of quartz glass(top layer),plexiglass(middle layer)and quartz glass(bottom layer);the imaging detection system was made up of a relay lens,a light source,a camera,a beam splitter and a filter.A signal processing algorithm was written with MATLAB to achieve accurate extraction of fluorescent signals.The system performance was tested and evaluated using Salmonella typhi as the test sample.Results The system designed realized highly sensitive detection of Salmonella typhi with a detection time of 30 min and a sensitivity of 3.5×10^(3) cfu/mL.Conclusion The digital immunoassay system designed is easy to operate,simplifies the sample processing process,lowers the lower limit of sample concentration and meets the need for rapid and accurate detection of pathogenic microorganisms under field conditions.