Biosensors, microfluidics systems and lateral flow assays for circulating microRNA detection: A review

MicroRNAs (miRNAs) are short RNA sequences found in eukaryotic cells and they are involved in several diseases pathogenesis including different types of cancers, metabolic and cardiovascular disorders. Thus, miRNAs circulating in serum, plasma, and other body fluids are employed as biomarkers for diagnostic and prognostic purposes and in assessment of drug response. Thus, various methods have been developed for detection of miRNAs including northern blotting, reverse transcriptase polymerase chain reaction (RT-PCR), next-generation sequencing, microarray, and isothermal amplification that are recognized as traditional methods. Considering the importance of early diagnosis and treatment of miRNAs-related diseases, development of simple, one-step, sensitive methods is of great interest. Nowadays developing technologies including lateral flow assay, biosensors (optical and electrochemical) and microfluidic systems which are simple fast responding, user-friendly, and are enabled with visible detection have gained considerable attention. This review briefly discusses miRNAs detection' methods, with a particular focus on lateral flow assay, biosensors, and microfluidic systems as novel and practical procedures.