DQF Fluorescent Dye – A Rhodamine-Based Dye with Large Stokes Shift

Organic small-molecule fluorescent dyes have been widely applied in functional molecular labeling and detection, offering real-time, in-situ visualization for various biomedical research applications. However, most commonly used fluorescent dyes—such as fluorescein, rhodamine, oxazine, and cyanine—suffer from small Stokes shifts (typically <30 nm), leading to:

• Low signal-to-noise ratio, affecting imaging accuracy.
• Severe fluorescence self-quenching, limiting biological imaging applications.

To address this limitation, the Zhang Xiaobing-Yuan Lin research group at Hunan University developed a general strategy known as Alternating Vibronic Structures (Vibration Structures) to increase the Stokes shift of conventional fluorescent dyes. This breakthrough led to the successful synthesis of DQF fluorescent dyes, a novel class of rhodamine-based dyes with enhanced optical properties.

Professor Yuan Lin is a professor and doctoral supervisor at the School of Chemistry and Chemical Engineering, Hunan University and the State Key Laboratory of Chemical Biosensing and Metrology.Currently, he has published more than 100 papers in international academic journals, with a total citation of more than 12,000 times, and an h-index of 58.Among them, the first or corresponding author from 2012 to presentJ. Am. Chem. Soc.10 articles、 Nat. Commun.1 articles、 Angew. Chem. Int. Ed.10 articles、CCS Chem.1 articles、Chem. Sci.4 articles、Anal. Chem.10 articles、Adv. Funct. Mater、BiomaterialsPublished more than 70 papers in journals and other journals. Mainly engaged in research on small molecule fluorescent probes and their applications.

Key Advantages of DQF Fluorescent Dyes

Compared to traditional rhodamine dyes, DQF fluorescent dyes—including DQF-560, DQF-565, and DQF-584 Figure 1—offer:

Larger Stokes shift → Reduces fluorescence self-quenching, improving imaging clarity.
Better photostability → Ensures long-term fluorescence retention under imaging conditions.
Higher signal-to-noise ratio → Ideal for high-precision imaging.
Enhanced suitability for long-term bioimaging → Applicable to cells, tissues, and in vivo imaging Figures 2 & 3.

These features make DQF fluorescent dyes a powerful tool for biomedical imaging, particularly for applications requiring high contrast and long-term stability.

Figure 1 DQF dyes¹

Applications of DQF Fluorescent Dyes

• High-contrast imaging for biological research
• Long-term imaging of living cells and tissues
• In vivo fluorescence imaging with minimal signal loss

J&K Scientific offers high-purity DQF fluorescent dyes, ensuring reliable performance for advanced imaging applications.

Figure 2 (a) Confocal fluorescence images of live HepG2 cells cultured with DQF-570 5.0 μM and Rh6G 5.0 μM with continuous irradiation using confocal microscope with the same parameters. (b) Quantification of the relative mean fluorescence levels of cells from the images of DQF-570 and Rh6G. ¹

Figure 3  Intracellular multi-color image of Rh6G 2 μM and LysoDQF-570 2 μM in HepG2 cells simulated with chloroquine 100 μM at different time points. ¹

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References

1. J. Am. Chem. Soc. 2018, 140, 24, 7716–7722.