title: A colorimetric biosensor for detection of attomolar microRNA with a functional nucleic acid-based amplification machine.
abstract: A functional nucleic acid-based amplification machine was designed for simple and label-free ultrasensitive colorimetric biosensing of microRNA (miRNA). The amplification machine was composed of a complex of trigger template and C-rich DNA modified molecular beacon (MB) and G-rich DNA (GDNA) as the probe, polymerase and nicking enzyme, and a dumbbell-shaped amplification template. The presence of target miRNA triggered MB mediated strand displacement to cyclically release nicking triggers, which led to a toehold initiated rolling circle amplification to produce large amounts of GDNAs. The formed GDNAs could stack with hemin to form G-quadruplex/hemin DNAzyme, a well-known horseradish peroxidase (HRP) mimic, for catalyzing a colorimetric reaction. The modified MB improved the stringent target recognition and reduced background signal. The proposed sensing strategy showed very high sensitivity and selectivity with a wide dynamic range from 10 aM to 1.0 nM, and enabled successful visual analysis of trace amount of miRNA in real sample by the naked eye. This rapid and highly efficient signal amplification strategy provided a simple and sensitive platform for miRNA detection. It would be a versatile and powerful tool for clinical molecular diagnostics.
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Li
authors.affiliation: Molecular Oncology and Epigenetics Laboratory, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yurong
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China; State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China. Electronic address: hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
authors.affiliation: Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education), College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China. Electronic address: dingshijia@163.com.
authors.forename: Shijia
authors.initials: S
authors.lastname: Ding
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D003124:Colorimetry / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D015345:Oligonucleotide Probes / Q000235:genetics; D013997:Time Factors
chemical_list: D035683:MicroRNAs; D015345:Oligonucleotide Probes
keywords: Colorimetric biosensing; DNAzyme; MicroRNA; Signal amplification; Toehold initiated rolling circle amplification