State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China; Changchun University of Science and Technology, Changchun, Jilin, 130022, China.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China; Department of Chemistry, University of Science & Technology of China, Hefei, Anhui, 230026, China.
Anal Chim Acta. 2019 Nov 4;1079:171-179. doi: 10.1016/j.aca.2019.06.048. Epub 2019 Jun 29.
Recent study proves that the combination of loop mediated isothermal nucleic acid amplification (LAMP) with one-step strand displacement (OSD) is of great help to improve the sequence specificity during genetic detection. However, because OSD is incapable of signal amplification, the signal-to-noise ratio or the observable signal change may be usually not significant enough to satisfy practical usage. With the purpose to overcome this challenge, herein a more advanced and practical sensing principle is developed with the OSD replaced by an amplifiable nucleic acid circuit, hybridization chain reaction (HCR). The very contagious norovirus (NoV) was employed as the model target. Compared with LAMP-OSD, the LAMP-HCR can detect as few as 30 copies of NoV gene in 2% fecal samples with significantly enlarged signal change and signal-to-background ratio. Therefore, more reliable detection is achieved. Moreover, due to the high compatibility of HCR, the final LAMP-HCR products can be flexibly transduced into different types of readouts, including fluorescence, flow cytometer (FCM) and even a personal glucose meter (PGM). This further enlarges the operating environments for the detection from hospital labs, bedsides, to potential off-the-shelf devices in local pharmacies. Especially when using FCM or PGM, with the assistance of magnetic beads (MBs), the detection shows even higher tolerance capability to complicated biological matrices.
最近的研究证明，环介导等温核酸扩增（LAMP）与一步链置换（OSD）的结合有助于提高遗传检测过程中的序列特异性。然而，由于 OSD 不能进行信号放大，因此信号与噪声比或可观察到的信号变化通常不够显著，无法满足实际应用的要求。为了克服这一挑战，本文提出了一种更为先进和实用的传感原理，用可扩增的核酸电路——杂交链式反应（HCR）替代 OSD。非常具有传染性的诺如病毒（NoV）被用作模型靶标。与 LAMP-OSD 相比，LAMP-HCR 可以在 2%的粪便样本中检测到低至 30 个拷贝的 NoV 基因，信号变化和信号与背景比显著增大。因此，可以实现更可靠的检测。此外，由于 HCR 的高兼容性，最终的 LAMP-HCR 产物可以灵活地转化为不同类型的读出方式，包括荧光、流式细胞仪（FCM），甚至是个人血糖仪（PGM）。这进一步扩大了检测的操作环境，从医院实验室、床边，到当地药店的潜在现成设备。特别是当使用 FCM 或 PGM 时，在磁珠（MBs）的辅助下，检测对复杂的生物基质具有更高的容忍能力。
