Signal-on Protein Detection via Dye Translocation between Aptamer and Quantum Dot.
A unique interaction between the cyanine dye and negatively charged quantum dot is used to construct a signal-on biaptameric quantum dot (QD) Förster resonance energy transfer (FRET) beacon for protein detection and distinct aptamer characterization. The beacon comprises a pair of aptamers, one intercalated with the cyanine dye (YOYO-3) and the other conjugated to a negatively charged, carboxyl-QD. When the target protein is present, structural folding and sandwich association of the two aptamers take place. As a consequence, YOYO-3 is displaced from the folded aptamer and transferred to the unblocked QD surface to yield a target concentration-dependent FRET signal. As a proof-of-principle, we demonstrate the detection of thrombin ranging from nanomolar to submicromolar concentrations and confirm the dye translocation using cylindrical illumination confocal spectroscopy (CICS). The proposed beacon provides a simple, rapid, signal-on FRET detection for protein as well as a potential platform for distinct aptamer screening.
Department of Biomedical Engineering, Columbia University , New York, New York 10027, United States.
Yeh-Hsing
YH
Lao
Department of Bio-Industrial Mechatronics Engineering, National Taiwan University , Taipei 10617, Taiwan.
Chun-Wei
CW
Chi
Sarah M
SM
Friedrich
Institute of Biomedical Sciences, Academia Sinica , Taipei 11529, Taiwan.
Konan
K
Peck
Tza-Huei
TH
Wang
Department of Biomedical Engineering, Columbia University , New York, New York 10027, United States.
Kam W
KW
Leong
Department of Bio-Industrial Mechatronics Engineering, National Taiwan University , Taipei 10617, Taiwan.
Lin-Chi
LC
Chen
D052158:Aptamers, Peptide / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D010080:Oxazoles / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
D052158:Aptamers, Peptide; D005456:Fluorescent Dyes; D010080:Oxazoles; C412625:YoYo-3; D013917:Thrombin
FRET; aptamer; dye translocation; intercalating dye; quantum dot