posted on 2022-05-24, 11:07authored byChuan Huang, Lu Zhang, Yuanna Zhu, Zuhao Zhang, Yunqing Liu, Chao Liu, Shenguang Ge, Jinghua Yu
This
work proposed a novel double-engine powered paper photoelectrochemical
(PEC) biosensor based on an anode–cathode cooperative amplification
strategy and various signal enhancement mechanisms, which realized
the monitoring of multiple miRNAs (such as miRNA-141 and miRNA-21).
Specifically, C3N4 quantum dots (QDs) sensitized
ZnO nanostars and BiOI nanospheres simultaneously to construct a composite
photoelectric layer that amplified the original photocurrent of the
photoanode and photocathode, respectively. Through the independent
design and partition of a flexible paper chip to functionalize injection
holes and electrode areas, the bipolar combination completed the secondary
upgrade of signals, which also provided biological reaction sites
for multitarget detection. With the synergistic participation of a
three-dimensional (3D) DNA nanomachine and programmable CRISPR/Cas12a
shearing tool, C3N4 QDs lost their attachment
away from the electrode surface to quench the signal. Moreover, electrode
zoning significantly reduced the spatial cross talk of related substances
for multitarget detection, while the universal trans-cleavage capability
of CRISPR/Cas12a simplified the operation. The designed PEC biosensor
revealed excellent linear ranges for detection of miRNA-141 and miRNA-21,
for which the detection limits were 5.5 and 3.4 fM, respectively.
With prominent selectivity and sensitivity, the platform established
an effective approach for trace multitarget monitoring in clinical
applications, and its numerous pioneering attempts owned favorable
reference values.