Electrochemical genosensors for the detection of cancer-related miRNAs

MicroRNAs (miRNAs), new stars of human genetics, are naturally occurring, 19-25 base pair, noncoding RNAs that regulate gene expression posttranscriptionally and have been demonstrated to be excellent biomarkers for cancer diagnosis/prognosis. Because of their short length, sequence similarity, and very low concentration, their detection in real samples is challenging. Among other methods for miRNA detection, electrochemical nucleic acid biosensors exhibit relevant advantages in terms of high sensitivity, ease of use, short assay time, nontoxic experimental steps, and adaptability to point-of-care testing. This article gives a brief overview of recent advances in the rapidly developing area of electrochemical biosensors for miRNA detection. The fundamentals of the different strategies developed to achieve novel signal amplification and sensitive electrochemical detection are discussed, and some examples of relevant approaches are highlighted, along with future prospects and challenges.