title: Probes for biomolecules detection based on RET-enhanced fluorescence polarization.
abstract: Fluorescent probes based on the principle of resonance energy transfer (RET) or the principle of fluorescence polarization (FP) are already used to detect biomolecules independently. However, there were no in-depth studies about the impact of RET on FP. Also, very few studies gave a comprehensive analysis on how to effectively design such a fluorescent probe. Based on the principle of resonance energy transfer (RET), we constructed fluorescent probes (SA-488-sub-nanogold) using streptavidin labeled Alexa488 (SA-488), nanogold and biotinylated substrate peptide (biotin-subpeptide). The influence of the structure and the ingredients of the substrate peptide were discussed. After SA-488 was combined with the biotin-subpeptide and the nanogold, its fluorescence intensity (FI) would be suppressed due to the energy transfer, leading to an increase in its volume and mass. The suppression of the FI led to a decrease in SA-488's effective concentration, and the increase in the volume or mass prolonged the SA-488's rotational relaxation time. Both changes increased SA-488's polarization in the solution. Therefore, the FP performance of the probe is enhanced by the RET. Using the probe, trypsin and biotin were detected by the change in both fluorescence intensity and fluorescence polarization, showing higher reliability, higher sensitivity, and a lower detection limit.
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China. Electronic address: rendh@tsinghua.edu.cn.
authors.forename: Dahai
authors.initials: D
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: You
mesh_terms: D000595:Amino Acid Sequence; D015374:Biosensing Techniques / Q000379:methods; D001710:Biotin / Q000032:analysis*; D019921:Biotinylation; D005454:Fluorescence Polarization / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry; D014357:Trypsin / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D010455:Peptides; D001710:Biotin; D006046:Gold; D019809:Streptavidin; D014357:Trypsin
keywords: Fluorescence polarization; Fluorescent probe; Nanogold; Resonance energy transfer