title: Colorimetric detection of sequence-specific microRNA based on duplex-specific nuclease-assisted nanoparticle amplification.
abstract: Developing simple and rapid methods for sequence-specific microRNA (miRNA) analysis is imperative to the miRNA study and use in clinical diagnosis. We have developed a colorimetric method for miRNA detection based on duplex-specific nuclease (DSN)-assisted signal amplification coupled to the aggregation of gold nanoparticles (AuNPs). The proposed method involves two processes: target-mediated probe digestion by a DSN enzyme and probe-triggered AuNP aggregation as a switch for signal output. The reaction system consists of a rationally designed probe complex formed by two partly complementary DNA probes, and two sets of different oligonucleotide-modified AuNPs with sequences complementary to a DNA probe in the probe complex. In the presence of target miRNA, the probe complex is invaded, resulting in the formation of a miRNA-probe heteroduplex as the substrate of the DSN enzyme, and releasing the other probe to link to the AuNPs. The proposed method allows quantitative detection of miR-122 in the range of 20 pM to 1 nM with a detection limit of ∼16 pM, and shows an excellent ability to discriminate single-base differences. Moreover, the detection assay can be applied to accurately quantify miR-122 in cancerous cell lysates which is in excellent agreement with the results from a commercial miRNA detection kit. This method is simple, cost-effective, highly selective, and free of dye label and separation procedures.
authors.affiliation: Lab of Biosystem and Microanalysis, Biomedical Nanotechnology Center, State Key Laboratory of Bioreactor Engineering, East China University of Science & Technology, Shanghai, 200237, China. binchengyin@ecust.edu.cn bcye@ecust.edu.cn.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Ru-Dong
authors.initials: RD
authors.lastname: Li
authors.forename: Bin-Cheng
authors.initials: BC
authors.lastname: Yin
authors.forename: Bang-Ce
authors.initials: BC
authors.lastname: Ye
mesh_terms: D000818:Animals; D033381:Anomura / Q000201:enzymology; D001483:Base Sequence; D045744:Cell Line, Tumor; D003124:Colorimetry / Q000379:methods*; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism*; D005240:Feasibility Studies; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D035683:MicroRNAs / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D013379:Substrate Specificity
chemical_list: D035683:MicroRNAs; D006046:Gold; D004247:DNA; D004720:Endonucleases