Viral protein-based bioanalytical tools for small RNA biosensing

Small RNAs, in particular microRNAs (miRNAs), are important regulators of gene expression and many pathological conditions, which have now been definitively linked to the development of cancer. Therefore, accurate and sensitive quantification of miRNAs may result in correct disease diagnosis, establishing these small noncoding RNA transcripts as valuable biomarkers. Aiming at overcoming some limitations of conventional quantification strategies, viral proteins offer interesting alternatives to small RNA biosensing. In this review, an up-to-date critical account of recombinant viral protein-based strategies, involving different readout techniques, for miRNA determination is provided. The variety of viral protein-based strategies for miRNA quantification that have appeared in recent years highlights this growing research field, which has not only several challenges but also great opportunities to develop sensitive, reliable, robust, and cost-effective small RNA biosensing methodologies.