The development of electrochemical assays for microRNAs

Twenty years has passed since the first discovery of microRNA (miRNA) lin-4 in Caenorhabditis elegans. Over the last decade, the study of miRNA biology has attracted tremendous attention. Increasing evidence has demonstrated that miRNA dysregulation could lead to a large number of genetic diseases and miRNA expressions are closely associated with the pathogenesis of most human malignancies. Recent studies have further suggested that miRNA expression profiles may serve as reliable biomarkers for cancer diagnosis, prognosis, and therapy. This provides powerful impetus and a growing demand for researchers to develop a simple analytical methodology which will allow an accurate, sensitive, selective, and cost effective miRNA analysis at point-of-care. In this regard, electrochemical methods offer many attractive characteristics and could play a leading role in future miRNA detection and quantification. This review revisits the discovery of miRNA, examines the possibility of miRNA biomarkers, discusses the conventional methods and emerging techniques for miRNA detection and quantification, and postulates future prospects in connection to electrochemical detection and quantification of miRNAs. It is hoped that this review will open new perspectives toward the development of new and novel electrochemical strategies for miRNA detection and quantification.