1 research outputs found
Ultrasensitive Detection of MicroRNA in Human Saliva via Rolling Circle Amplification Using a DNA-Decorated Graphene Oxide Sensor
MicroRNAs (miRNAs) are a family of conserved small noncoding
RNAs
whose expression is associated with many diseases, including cancer.
Salivary miRNAs are gaining popularity as noninvasive diagnostic biomarkers
for cancer and other systemic disorders, but their use is limited
by their low abundance and complicated detection procedure. Herein,
we present a novel self-assembly approach based on rolling circle
amplification (RCA) and graphene oxide (GO) for the ultrasensitive
detection of miRNA21 and miRNA16 (miRNA oral cancer biomarkers in
human saliva). First, target miRNA hybridizes with the RCA template.
In the presence of DNA polymerase, the RCA reaction is induced and
sequences matching the template are generated. Then, a nicking enzyme
cuts the long ssDNA product into tiny pieces to obtain the amplified
products. The DNA-decorated GO sensor was fabricated by preabsorbing
the ssDNA fluorescence-labeled probe on the GO surface, resulting
in fluorescence quenching. The DNA-decorated GO sensor could detect
the amplified product via the self-assembly of dsDNA, leading to the
desorption and recovery of the fluorescence-labeled probe. Under optimal
conditions, the proposed system exhibited ultrasensitive detection;
the detection limits of miRNA16 and miRNA21 were 8.81 and 3.85 fM,
respectively. It showed a wide range of detection between 10 fM and
100 pM for miRNA16 and between 10 fM and 1 nM for miRNA16. It demonstrated
high selectivity, distinguishing between 1- and 3-mismatch nucleotides
in target miRNA. Overall, our proposed DNA-decorated GO sensor can
accurately detect the salivary miRNAs and may potentially be used
for the diagnosis and screening of early-stage oral cancer