title: Simple, sensitive and label-free electrochemical detection of microRNAs based on the in situ formation of silver nanoparticles aggregates for signal amplification.
abstract: This work presented a simple, sensitive and label-free electrochemical method for the detection of microRNAs (miRNAs). It is based on the boronate ester covalent interaction between 4-mercaptophenylboronic acid (MPBA) and cis-diol at the 3'-terminal of miRNAs and the MPBA-induced in situ formation of citrate-capped silver nanoparticles (AgNPs) aggregates as labels on the electrode surface. In this design, MPBA acted as the cross-linker of AgNPs assembly. Specifically, the thiolated hairpin-like DNA probe was assembled onto the gold nanoparticles (nano-Au) modified electrode surface through the Ag-S interaction. After hybridization with the target miRNAs, MPBA was anchored onto the 3'-terminal of miRNAs through the formation of a boronate ester bond and then captured AgNP via the Ag-S interaction. Meanwhile, free MPBA molecules in solution induced the in situ assembly of AgNPs on electrode surface through the covalent interactions between α-hydroxycarboxylate of citrate and boronate of MPBA and the formation of Ag-S bonds. The electrochemical signal was therefore amplified due to the formation of AgNPs network architecture. To demonstrate the feasibility and analytical performances of the method, miRNA-21 was determined as a model analyte. The detection limit was found to be 20 aM. The viability of our method for biological sample assays was demonstrated by measuring the miRNA-21 contents in three human serum samples. In contrast to other signal-amplified electrochemical strategies for miRNAs detection, our method requires simple detection principle and easy operation procedure and obviates the specific modification of nanoparticles and capture/detection probes.
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xia
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Peizhen
authors.initials: P
authors.lastname: Peng
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Liping
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Mengsha
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China.
authors.forename: Jiebin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Henan Province of Key Laboratory of New Optoelectronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang, Henan 455000, People's Republic of China; Henan Key Laboratory of Biomolecular Recognition and Sensing, Shangqiu Normal University, Shangqiu, Henan 476000, People's Republic of China. Electronic address: liulin@aynu.edu.cn.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D035683:MicroRNAs / Q000737:chemistry / Q000302:isolation & purification*; D009693:Nucleic Acid Hybridization; D012834:Silver / Q000737:chemistry
chemical_list: D035683:MicroRNAs; D012834:Silver; D006046:Gold
keywords: Electrochemical genosensor; Hairpin-like probe; MicroRNAs; Phenylboronic acid; Signal amplification; Silver nanoparticles