2 research outputs found
Electrochemically Mediated Surface-Initiated de Novo Growth of Polymers for Amplified Electrochemical Detection of DNA
The
development of convenient and efficient strategies without involving
any complex nanomaterials or enzymes for signal amplification is of
great importance in bioanalytical applications. In this work, we report
the use of electrochemically mediated surface-initiated atom transfer
radical polymerization (SI-eATRP) as a novel amplification strategy
based on the de novo growth of polymers (dnGOPs) for the electrochemical
detection of DNA. Specifically, the capture of target DNA (tDNA) by
the immobilized peptide nucleic acid (PNA) probes provides a high
density of phosphate groups for the subsequent attachment of ATRP
initiators onto the electrode surface by means of the phosphate-Zr<sup>4+</sup>-carboxylate chemistry, followed by the de novo growth of
electroactive polymer via the SI-eATRP. De novo growth of long polymeric
chains enables the labeling of numerous electroactive probes, which
in turn greatly improves the electrochemical response. Moreover, it
circumvents the slow kinetics and poor coupling efficiency encountered
when nanomaterials or preformed polymers are used and features sufficient
flexibility and simplicity in controlling the degree of signal amplification.
Under optimal conditions, it allows a highly sensitive and selective
detection of tDNA within a broad linear range from 0.1 fM to 0.1 nM
(<i>R</i><sup>2</sup> = 0.996), with the detection limit
down to 0.072 fM. Compared with the unamplified method, more than
1.2 × 10<sup>6</sup>-fold sensitivity improvement in DNA detection
can be achieved. By virtue of its simplicity, high efficiency, and
cost-effectiveness, the proposed dnGOPs-based signal amplification
strategy holds great potential in bioanalytical applications for the
sensitive detection of biological molecules
Cyanocobalamin (VB<sub>12</sub>) Bionic Enzyme-Assisted Photocatalytic Chain-Growth Polymerization for Detection of Lung Cancer Biomarkers
Cobalt-mediated radical polymerization is noted for its
great level
of control over the polymerization of acrylic and vinyl esters monomers,
even at high molar mass. Vitamin B12, a natural bionic
enzyme cobalt complex, involves the conversion of organic halides
to olefins through chain-growth polymerization. In this work, the
notion of R-Co(III) free radical persistent free radical effect and
vitamin B12 circulation were first reported for the perception
of ultralow abundance of microRNA-21, a lung cancer biomarker. Indeed,
most Co-containing catalytic reactions can occur under mild conditions
due to their minimal bond dissociation of the C–Co bond, with
blue light irradiation. Based on the intrinsic stability of the vitamin
B12 framework and recycling of the catalyst, it is evident
that this natural catalytic scheme has potential applications in medicinal
chemistry and biomaterials. In addition, this strategy, combined with
highly specific recognition probes and vitamin B12 circulation-mediated
chain-growth polymerization, has a detection limit as low as 910 aM.
Furthermore, it is sensitive for sensing in serum samples containing
biomarkers and shows great potential for RNA selection and amplification
sensing in clinical samples