Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
PLoS One. 2019 Jun 27;14(6):e0218571. doi: 10.1371/journal.pone.0218571. eCollection 2019.
This paper reports an outdoor-use polymerase chain reaction (PCR) technology in which stability of resistance temperature detectors (RTDs) is remarkably improved. A thin-film RTD made of non-annealed Pt shows accuracy degradation because the resistance of the RTD tends to decrease during the PCR operation. Thus, the annealing process is applied to the Pt RTD to improve the stability, which is a prerequisite to the accurate measurement of the absolute temperature. Both heaters and the RTD are fabricated on a thin quartz substrate whose melting temperature is high enough for annealing. The performances in the PCR time and power consumption are enhanced by reducing the size of the heater chips with no degradation in the temperature uniformity. A spring-loaded electrode is employed to simplify the procedure of electrical connection to the thermal controller and loading/unloading of the PCR chip. The contact area of the electrical connection is so small that the conductive thermal resistance increases; thereby small heat dissipation can be exploited for low-power operation. The stability of the RTD is experimentally confirmed in terms of resistance variation over repeated PCR operations (four times). The least variation of 0.005%, which corresponds to a negligible temperature variation of 0.038 °C for the PCR, is achieved from the RTD annealed for 5 min at 450 °C. The gel-electrophoresis result indicates that the PCR performance of the proposed system using a film-type PCR chip is comparable to that of a conventional system using a vial tube despite its low power consumption.
本文报道了一种户外用聚合酶链反应（PCR）技术，该技术显著提高了电阻温度探测器（RTD）的稳定性。由于在 PCR 操作过程中 RTD 的电阻有下降的趋势，因此由非退火 Pt 制成的薄膜 RTD 的准确性会降低。因此，需要对 Pt RTD 进行退火处理以提高稳定性，这是准确测量绝对温度的前提。加热器和 RTD 都制作在薄的石英衬底上，该衬底的熔点足够高，可以进行退火处理。通过减小加热器芯片的尺寸，同时保持温度均匀性不变，提高了 PCR 时间和功耗性能。采用弹簧加载电极来简化与热控制器的电气连接以及 PCR 芯片的加载/卸载过程。电连接的接触面积很小，因此电传导热阻增加，从而可以利用小的热耗散来实现低功耗操作。通过重复进行四次 PCR 操作来验证 RTD 的稳定性，实验结果表明，RTD 的电阻变化最小为 0.005%，这对应于 PCR 温度变化可忽略不计的 0.038°C。从 450°C 退火 5 分钟的 RTD 中可以实现。凝胶电泳结果表明，尽管该系统的功耗较低，但使用薄膜型 PCR 芯片的系统的 PCR 性能与使用试管的传统系统相当。
