ac6b02481_si_001.pdf (401.61 kB)
Ligating Dopamine as Signal Trigger onto the Substrate via Metal-Catalyst-Free Click Chemistry for “Signal-On” Photoelectrochemical Sensing of Ultralow MicroRNA Levels
journal contribution
posted on 2016-11-07, 00:00 authored by Cui Ye, Min Qiang Wang, Zhong Feng Gao, Ying Zhang, Jing Lei Lei, Hong Qun Luo, Nian Bing LiThe
efficiency of photon-to-electron conversion is extremely restricted
by the electron–hole recombinant. Here, a new photoelectrochemical
(PEC) sensing platform has been established based on the signal amplification
of click chemistry (CC) via hybridization chain reaction (HCR) for
highly sensitive microRNA (miRNA) assay. In this proposal, a preferred
electron donor dopamine (DA) was first assembled with designed ligation
probe (probe-N3) via amidation reaction to achieve DA-coordinated
signal probe (PDA-N3). The PDA-N3 served as a flexible trigger to signal amplification through
efficiently suppressing the electron–hole recombinant. Specifically,
the PDA-N3 can be successfully ligated into
the trapped hairpins (H1 and H2) via the superior ligation method
of metal-catalyst-free CC, in which the electron donor DA was introduced
into the assay system. Moreover, the enzyme-free HCR, employed as
a versatile amplification way, ensures that lots of PDA-N3 can be attached to the substrate. This PEC sensing
for miRNA-141 detection illustrated the outstanding linear response
to a concentration variation from 0.1 fM to 0.5 nM and a detection
limit down to 27 aM, without additional electron donors. The sensor
is further employed to monitor miRNA-141 from prostate carcinoma cell
(22Rv1), showing good quantitative detection capability. This strategy
exquisitely influences the analytical performance and offers a new
PEC route to highly selective and sensitive detection of biological
molecules.