Department of Chemistry, Seoul National University, Seoul, 151-747, Republic of Korea.
ACS Nano. 2013 Jul 23;7(7):5882-91. doi: 10.1021/nn401183s. Epub 2013 Jun 19.
MicroRNA (miRNA) is an important small RNA which regulates diverse gene expression at the post-transcriptional level. miRNAs are considered as important biomarkers since abnormal expression of specific miRNAs is associated with many diseases including cancer and diabetes. Therefore, it is important to develop biosensors to quantitatively detect miRNA expression levels. Here, we develop a nanosized graphene oxide (NGO) based miRNA sensor, which allows quantitative monitoring of target miRNA expression levels in living cells. The strategy is based on tight binding of NGO with peptide nucleic acid (PNA) probes, resulting in fluorescence quenching of the dye that is conjugated to the PNA, and subsequent recovery of the fluorescence upon addition of target miRNA. PNA as a probe for miRNA sensing offers many advantages including high sequence specificity, high loading capacity on the NGO surface compared to DNA and resistance against nuclease-mediated degradation. The present miRNA sensor allowed the detection of specific target miRNAs with the detection limit as low as ~1 pM and the simultaneous monitoring of three different miRNAs in a living cell.
微小 RNA（miRNA）是一种重要的小 RNA，可在后转录水平调节多种基因表达。miRNA 被认为是重要的生物标志物，因为特定 miRNA 的异常表达与包括癌症和糖尿病在内的许多疾病有关。因此，开发用于定量检测 miRNA 表达水平的生物传感器非常重要。在这里，我们开发了一种基于纳米级氧化石墨烯（NGO）的 miRNA 传感器，可定量监测活细胞中靶 miRNA 的表达水平。该策略基于 NGO 与肽核酸（PNA）探针的紧密结合，导致与 PNA 缀合的染料的荧光猝灭，并且随后在添加靶 miRNA 时恢复荧光。PNA 作为 miRNA 传感的探针具有许多优点，包括高序列特异性、与 DNA 相比 NGO 表面上的高载量以及对核酸酶介导的降解的抗性。本 miRNA 传感器允许以低至约 1 pM 的检测限检测特定的靶 miRNA，并同时在活细胞中监测三种不同的 miRNA。
