When Molecular Probes Meet Self-Assembly: An Enhanced Quenching Effect

• Published in: Angewandte Chemie International Edition 2015-04, Vol.54 (16), p.4823-4827
• Main Authors: Ren, Chunhua, Wang, Huaimin, Mao, Duo, Zhang, Xiaoli, Fengzhao, Qianqi, Shi, Yang, Ding, Dan, Kong, Deling, Wang, Ling, Yang, Zhimou
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Apoptosis - drug effects; Enzymes; Fluorescein-5-isothiocyanate - chemistry; Fluorescein-5-isothiocyanate - metabolism; Fluorescein-5-isothiocyanate - toxicity; Fluorescence; fluorescence quenching; Fluorescence Resonance Energy Transfer; Fluorescent Dyes - chemistry; Fluorescent Dyes - metabolism; Fluorescent Dyes - toxicity; HeLa Cells; Humans; Microscopy, Confocal; molecular probes; Molecular Probes - chemistry; Molecular Probes - metabolism; Molecular Probes - toxicity; peptide; Peptides - chemical synthesis; Peptides - chemistry; Peptides - metabolism; Phenylalanine; Quenching; Quenching (cooling); Recognition; Rhodamines - chemistry; Rhodamines - metabolism; Rhodamines - toxicity; Self assembly; Signal-To-Noise Ratio; Strategy
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201411833

We demonstrate that the incorporation of one or two amino acids of phenylalanine (F) or 4‐fluoro phenylalanine (fF) will greatly lower the background fluorescence intensities of conventional quenched probes with quenchers. This enhanced quenching effect was due to the synergetic effect of the aggregation caused quenching and the presence of a quencher. Such strategy will not greatly affect the enzyme recognition properties to the probes. We also demonstrated that our self‐assembled nanoprobe with the enhanced quenching effect showed a better performance in cells for the detection of cell apoptosis than the unassembled probes. Our study demonstrates that using molecular self‐assembly can optimize and improve the performance of molecular probes and it provides a simple but very useful strategy to boost the signal‐to‐noise ratios of fluorescence probes. The incorporation of one or two fluoro phenylalanine groups (fFs) in conventional quenched probes can lead to the production of self‐assembled probes with enhanced quenching effects. The self‐assembled probes possess similar enzyme recognition and fluorescence recovery properties. This provides a useful strategy for the design of molecular probes with good fluorescence turn‐on properties.