title: Surface plasmon resonance biosensor for sensitive detection of microRNA and cancer cell using multiple signal amplification strategy.
abstract: A sensitive and versatile surface plasmon resonance (SPR) biosensor was proposed for the detection of microRNA (miRNA) and cancer cell based on multiple signal amplification strategy. Thiol-modified hairpin probe, including a sequence complementary to the target miRNA, was first immobilized on the Au film. In the presence of target miRNA, the stem-loop structure of hairpin probe was unfolded, and then DNA-linked Au nanoparticles (AuNPs) were hybridized with the terminus of the unfolded hairpin probe. Subsequently, DNA-linked AuNPs initiated the formation of DNA supersandwich structure through the addition of two report DNA sequences. Owing to the electronic coupling between localized plasmon of the AuNPs and the surface plasmon wave, as well as the enhancement of the refractive index of the medium over the Au film induced by DNA supersandwich structure, the SPR response was significantly enhanced. Next, numerous positively charged silver nanoparticles (AgNPs) were absorbed onto the long-range DNA surpersandwich equably, resulting in a further increase of SPR response. Due to the enzyme-free multiple signal amplification strategy, as low as ca. 0.6 fM miRNA-21 could be detected. In addition, this biosensor showed high selectivity toward single-base mismatch. More importantly, this SPR biosensor was also used for cancer cell detection coupled with the cell-specific aptamer modified magnetic nanoparticles. Given that the biosensor avoided enzyme introduction, the limitation of the enzyme was overcome. The versatile biosensor has great potential for the broad applications in the field of clinical analysis.
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China.
authors: Rongjuan
authors: R
authors: Liu
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China. Electronic address: wwqq99@hnu.edu.cn.
authors: Qing
authors: Q
authors: Wang
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China.
authors: Qing
authors: Q
authors: Li
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China.
authors: Xiaohai
authors: X
authors: Yang
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China. Electronic address: kmwang@hnu.edu.cn.
authors: Kemin
authors: K
authors: Wang
authors: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China.
authors: Wenyan
authors: W
authors: Nie
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry*; D006801:Humans; D061925:Immobilized Nucleic Acids / Q000737:chemistry / Q000235:genetics; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics; D009369:Neoplasms / Q000175:diagnosis* / Q000235:genetics; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D009693:Nucleic Acid Hybridization / Q000379:methods; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D061925:Immobilized Nucleic Acids; C524940:MIRN21 microRNA, human; D058185:Magnetite Nanoparticles; D035683:MicroRNAs; D012834:Silver; D006046:Gold
keywords: Cancer cell; DNA supersandwich; Gold nanoparticles; MicroRNA; Silver nanoparticles; Surface plasmon resonance