Biocatalytic Amplification of UV Signal in Capillary Electrophoresis of MicroRNA

MicroRNAs (miRNAs) are new potential biomarkers for early diagnosis and classification of cancer. This study is the first attempt to use biocatalytic amplification reactions combined with capillary electrophoresis to detect multiple miRNAs simultaneously. In this way, miRNAs, as catalysts, can catalyze two single strands of DNA to form double-strand DNA. Feasibility was demonstrated by non-gel capillary electrophoresis coupled with UV detection (NGCE-UV). The detection limit was improved down to 1.0 nM, having ca. 10(3)-fold improvement. This method has a good linear range of between 3.0 nM and 300 nM, with R(2) at 0.99, recovery at 88–115%, and peak area precision at 1–12.7%. Using three target miRNAs as a model can achieve the baseline separation and good selectivity. The proposed biocatalysis coupled with a capillary electrophoresis-based method is simple, rapid, multiplexed, and cost-effective, making it potentially applicable for simultaneous, large-scale screening for other nucleic acids biomarkers and related research.