Genosensors, a nanomaterial-based platform for microRNA-21 detection, non-invasive methods in early detection of cancer

MicroRNAs are small non-coding RNAs that are 18-24 nucleotides in length. Among the most widely studied microRNAs, microRNA21 (miR21) is highly expressed in many mammalian cell types. It regulates numerous biological functions such as differentiation, proliferation, apoptosis, and migration. Therefore, sensitive and specific detection of miR-21 is crucial in medical approaches. Several methods such as ISH, northern blotting, RT-PCR, microarray, and next-generation are conventionally used to detect miR-21. Due to the limitations and problems related to routine methods, the development of advanced and modern methods has been one of the investigation goals of researchers in recent years. Nanotechnology-based methods have been among the most critical methods in the last two decades. Biosensors are one of the primary modern methods that largely overcome the limitations of routine procedures. The present study introduces and discusses routine methods for the detection of miR-21and the related up-to-date biosensors developed in recent years (2019-2021).