Colorimetric Sensing of MicroRNAs in Whole Blood for Early Diagnosis of Heart Failure

Timely detection of heart failure-specific biomarkers is crucial to reduce mortality, especially in aged patients. A lot of functional research has revealed the potential of microRNAs (miRNAs) to act as biomarkers for an early diagnosis of heart failure. Efficient miRNA sensing techniques, which can be performed in nonclinical environments, are highly desired. In this study, we develop a colorimetric technique (CQmiR) for rapid and quantitative miRNA sensing, which is capable of highly efficient and low-cost detection of multiple miRNAs with single-nucleotide specificity and sub-femtomolar sensitivity (10^-15 M) within 2 h. This is achieved by using an RNA-binding protein-coated nanoprobe patch for extracting miRNAs from complex biological samples, including whole blood, along with a loop-mediated isothermal amplification for on-chip miRNA amplification. Such CQmiR assays can be completed in a nonclinical environment without the need for any experimental equipment. By taking advantage of the CQmiR approach, we demonstrate presymptomatic detection of heart failure-associated molecular risk in a rodent model based on a 9-miRNA signature, highlighting the critical roles of miR-652-3p and miR-30e-5p.