Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA.
Anal Chem. 2013 Sep 3;85(17):8061-4. doi: 10.1021/ac4018346. Epub 2013 Aug 16.
Small RNA (19-23 nucleotides) molecules play an important role in gene regulation, embryonic differentiation, hematopoiesis, and a variety of cancers. Here, we present an ultrasensitive, extremely specific, label-free, and rapid electronic detection of microRNAs (miRNAs) using a carbon nanotubes field-effect transistor functionalized with the Carnation Italian ringspot virus p19 protein biosensor. miRNA-122a was chosen as the target, which was first hybridized to a probe molecule. The probe-miRNA duplex was then quantified by measuring the change in resistance of biosensor resulting from its binding to p19, which selects 21-23 bp RNA duplexes in a size-dependent but sequence-independent manner. The biosensor displayed a wide dynamic range up to 10(-14) M and was able to detect as low as 1 aM miRNA in the presence of a million-fold excess of total RNA, paving the way for simple, point-of-care, low-cost early detection of miRNA as a biomarker in diagnosis of many diseases, including cancer.
小 RNA（19-23 个核苷酸）分子在基因调控、胚胎分化、造血和多种癌症中发挥着重要作用。在这里，我们提出了一种超灵敏、极特异、无标记、快速的电子检测 microRNAs（miRNAs）的方法，该方法使用经过 Carnation Italian ringspot virus p19 蛋白生物传感器功能化的碳纳米管场效应晶体管。选择 miRNA-122a 作为靶标，首先将其与探针分子杂交。然后通过测量生物传感器结合 p19 导致的电阻变化来定量探针-miRNA 双链体，p19 以依赖于大小而非序列的方式选择 21-23bp 的 RNA 双链体。该生物传感器显示出高达 10(-14) M 的宽动态范围，并且能够在存在 100 万倍过量总 RNA 的情况下检测低至 1 aM 的 miRNA，为简单、即时、低成本的 miRNA 早期检测铺平了道路，miRNA 作为许多疾病（包括癌症）诊断的生物标志物。
