title: Silver enhanced ratiometric nanosensor based on two adjustable Fluorescence Resonance Energy Transfer modes for quantitative protein sensing.
abstract: We developed a silver decahedral nanoparticles (Ag10NPs)-enhanced ratiometric Fluorescence Resonance Energy Transfer (FRET) nanosensor based on two adjustable FRET modes. Alexa Fluor 488 (Alexa) and Cyanine3 (Cy3)-aptamer-Black hole quencher-2 (BHQ-2) were bound with Ag10NPs to form the ratiometric FRET nanosensor (Ag-Alexa/Cy3/BHQ-2). Alexa act as donor and Cy3 as acceptor in the FRET mode 1 while Cy3 was donor and BHQ-2 was acceptor in the FRET mode 2. In the absence of platelet-derived growth factor (PDGF-BB), the fluorescence intensity of Alexa was lowest while that of Cy3 was highest. Upon the addition of PDGF-BB, Cy3-aptamer-BHQ-2 binds with PDGF-BB resulting in the change of structure of aptamer. The fluorescence intensity of Alexa increased while that of Cy3 decreased. In addition, the fluorescence intensity ratio of Alexa to Cy3 increased remarkably with PDGF-BB concentration in the range of 0.4-400ng/mL. A good linear response was obtained when the PDGF-BB concentrations were in the range of 3.1-200ng/mL, with the limit of detection at 0.4ng/mL. When compared to sensors without Ag10NPs (Alexa/Cy3/BHQ-2) and one without BHQ-2 (Ag-Alexa/Cy3), the new nanosensor Ag-Alexa/Cy3/BHQ-2 showed remarkable increase in sensitivity.
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China.
authors: Hui
authors: H
authors: Li
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China.
authors: Yaju
authors: Y
authors: Zhao
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China.
authors: Zhu
authors: Z
authors: Chen
authors: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China. Electronic address: xudanke@nju.edu.cn.
authors: Danke
authors: D
authors: Xu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D000077214:Becaplermin; D015374:Biosensing Techniques / Q000379:methods; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D020574:Proto-Oncogene Proteins c-sis / Q000032:analysis*; D012834:Silver / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D005456:Fluorescent Dyes; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D012834:Silver
keywords: Aptamer; Metal enhanced fluorescence; PDGF-BB; Ratiometric FRET; Silver decahedral nanoparticles