MicroRNAs
(miRNAs) are endogenous molecules with regulatory functions.
The purification and enrichment of miRNA are essential for its precise
and sensitive detection. miRNA isolated using commercial kits contains
abundant interfering RNAs, and the concentration of miRNA may not
be adequate for detection. Herein, we prepared a reduced graphene
oxide (rGO)-based magnetic solid-phase extraction material for the
enrichment and ultrasensitive detection of miRNA from intricate nucleic
acid solutions. <i>In situ</i> reverse transcription (RT)
was developed as the most efficient approach to desorb miRNA from
rGO among the methods that are compatible for the subsequent amplification
reported thus far. Additionally, rolling circle amplification and
qPCR were used to detect let-7a with a decrease of the limit of detection
by 24.7- and 31.3-fold, respectively. This material was also successfully
used to extract and detect miRNA from total RNA isolated from human
plasma. Our results show that the material prepared in this study
has the potential for cancer biopsy in clinics and the discovery of
new miRNAs in scientific research
