Hitachi, Ltd., Central Research Laboratory, 1-280 Higashi-koigakubo, Kokubunji, Tokyo 185-8601, Japan.
Hitachi, Ltd., Central Research Laboratory, 1-280 Higashi-koigakubo, Kokubunji, Tokyo 185-8601, Japan.
J Biosci Bioeng. 2014 Sep;118(3):344-9. doi: 10.1016/j.jbiosc.2014.02.010. Epub 2014 Apr 13.
A simple and sensitive point-of-care-test (POCT) device for chemiluminescence (CL) immunoassay was devised and tested. The device consists of a plastic flow-channel reactor and two wireless-communication sensor chips, namely, a photo-sensor chip and a temperature-sensor chip. In the flow-channel reactor, a target antigen is captured by an antibody immobilized on the inner wall of the flow-channel and detected with enzyme labeled antibody by using CL substrate. The CL signal corresponding to the amount of antigen is measured by a newly developed radio-frequency-identification (RFID) sensor, which enables batteryless operation and wireless data communication with an external reader. As for the POCT device, its usage environment, especially temperature, varies for each measurement. Hence, temperature compensation is a key issue in regard to eliminating dark-signal fluctuation, which is a major factor in deterioration of the precision of the POCT device. A two-stage temperature-compensation scheme was adopted. As for the first stage, the signals of two photodiodes, one with an open window and one with a sealed window, integrated on the photo-sensor chip are differentiated to delete the dark signal. As for the second stage, the differentiated signal fluctuation caused by a temperature variation is compensated by using the other sensor chip (equipped with a temperature sensor). The dark-level fluctuation caused by temperature was reduced from 0.24 to 0.02 pA/°C. The POCT device was evaluated as a CL immunoassay of thyroid-stimulating hormone (TSH). The flow rate of the CL reagent in the flow channel was optimized. As a result, the detection limit of the POCT device was 0.08 ng/ml (i.e., 0.4 μIU/ml).
设计并测试了一种用于化学发光（CL）免疫分析的简单灵敏的即时检测（POCT）设备。该设备由一个塑料流动通道反应器和两个无线通信传感器芯片组成，即光传感器芯片和温度传感器芯片。在流动通道反应器中，目标抗原被固定在流动通道内壁上的抗体捕获，并使用 CL 底物与酶标记抗体进行检测。与外部读取器进行无线数据通信的新型射频识别（RFID）传感器测量对应于抗原量的 CL 信号。就 POCT 设备而言，其使用环境（特别是温度）因每次测量而有所不同。因此，温度补偿是消除暗信号波动的关键问题，暗信号波动是 POCT 设备精度恶化的主要因素。采用了两级温度补偿方案。对于第一级，通过对光传感器芯片上集成的两个光电二极管（一个带有开窗口，一个带有密封窗口）的信号进行差分来删除暗信号。对于第二级，通过使用另一个传感器芯片（配备温度传感器）补偿由温度变化引起的差分信号波动来进行温度补偿。温度引起的暗电平波动从 0.24 减少到 0.02 pA/°C。使用 CL 免疫分析甲状腺刺激激素（TSH）对 POCT 设备进行了评估。优化了流动通道中 CL 试剂的流速。结果，POCT 设备的检测限为 0.08 ng/ml（即 0.4 μIU/ml）。
