posted on 2021-02-02, 23:04authored byJi-Seon Lee, Seongchan Kim, Sungchul Kim, Kwangseog Ahn, Dal-Hee Min
A human
cytomegalovirus (HCMV) causes a persistent asymptomatic
infection in healthy individuals and possesses unexpected dangers
to newborn babies, immunocompromised people, and organ transplant
recipients because of stealth transmission. Thus, an early and accurate
diagnosis of HCMV infection is crucial for prevention of unexpected
transmission and progression of the severe diseases. The standard
method of HCMV diagnosis depends on serology, antigen test, and polymerase
chain reaction-based nucleic acid detection, which have advantages
for each target molecule. However, the serological test for an antibody
is an indirect method assuming the past virus infection, and antigen
and viral nucleic acid testing demand laborious, complex multistep
procedures for direct virus detection. Herein, we present an alternative
simple and facile fluorometric biosensor composed of a graphene oxide
nanocolloid and fluorescent peptide nucleic acid (PNA) probe to detect
the HCMV infection by simply monitoring the virally encoded microRNA
as a new biomarker of lytic virus infection. We verify the sensing
of HCMV-derived microRNA accumulated within 72 h after HCMV infection
and examine the diagnosis of HCMV in living cells. We proceed with
the time course and concentration-dependent investigation of hcmv-miRNA
sensing in living cells as a direct method of HCMV detection at the
molecular level on the basis of an intracellular hcmv-miRNA expression
profile and graphene oxide nanocolloid-based simple diagnostic platform.
The fluorometric biosensor enables the sequence-specific binding to
the target HCMV miRNAs in HCMV-infected fibroblasts and shows the
quantitative detection capability of HCMV infection to be as low as
4.15 × 105 immunofluorescence focus unit (IFU)/mL
of the virus titer at 48 h post-infection with picomolar sensitivity
for HCMV miRNA.