title: Y-shaped probe for convenient and label-free detection of microRNA-21 in vitro.
abstract: A simple, highly selective, and label-free microRNA (miRNA) detection method based on l-alanine-reduced graphene oxide fluorescence quenching with a Y-shaped probe is proposed. The Y-shaped probe was synthesized by silver nitrate and a cytosine-rich molecular beacon (MB) in two terminals through sodium borohydride reduction, which generated a stronger fluorescent signal than ordinary DNA-templated silver nanoclusters (AgNCs). Meanwhile, the Y-shaped probe contained a single-stranded loop structure, which could be superbly adsorbed onto the surface of reduced graphene oxide (RGO) via π-π stacking interaction, and this special structure of the probe was designed to improve its sensitivity and selectivity. In addition, the quenching capacities of graphene oxide (GO) and RGO were compared in this research. The strong interaction between nucleobases of the loop structure and RGO nanosheet made the MB-AgNCs-RGO system exhibit minimal background fluorescence. In the presence of miRNA-21, the loop structure of the Y-shaped probe can hybridize with target miRNA-21; the molecular beacon encapsulated probe is far away from RGO surface and produces a detectable signal. The MB-AgNCs based approach provides a label-free avenue to detect miRNA with high selectivity and good reproducibility, which has a promising application in early clinical diagnosis and biomedical research.
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.
authors: Kui
authors: K
authors: He
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.
authors: Rong
authors: R
authors: Liao
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China. Electronic address: cai_mao3@hotmail.com.
authors: Changqun
authors: C
authors: Cai
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.
authors: Caishuang
authors: C
authors: Liang
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.
authors: Chan
authors: C
authors: Liu
authors: Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China. Electronic address: chenxm_xt@163.com.
authors: Xiaoming
authors: X
authors: Chen
mesh_terms: D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D006801:Humans; D035683:MicroRNAs / Q000032:analysis*; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D015335:Molecular Probes
keywords: Clinical diagnosis; Reduced graphene oxide; Silver nanoclusters; Y-shaped probe; miRNA-21