Green and Red Fluorescent Dyes for Translational Applications in Imaging and Sensing Analytes: A Dual‐Color Flag

Abstract

Red and green are two of the most‐preferred colors from the entire chromatic spectrum, and red and green dyes are widely used in biochemistry, immunohistochemistry, immune‐staining, and nanochemistry applications. Selective dyes with green and red excitable chromophores can be used in biological environments, such as tissues and cells, and can be irradiated with visible light without cell damage. This critical review, covering a period of five years, provides an overview of the most‐relevant results on the use of red and green fluorescent dyes in the fields of bio‐, chemo‐ and nanoscience. The review focuses on fluorescent dyes containing chromophores such as fluorescein, rhodamine, cyanine, boron–dipyrromethene (BODIPY), 7‐nitobenz‐2‐oxa‐1,3‐diazole‐4‐yl, naphthalimide, acridine orange, perylene diimides, coumarins, rosamine, Nile red, naphthalene diimide, distyrylpyridinium, benzophosphole P‐oxide, benzoresorufins, and tetrapyrrolic macrocycles. Metal complexes and nanomaterials with these dyes are also discussed.

Lifetime and Fluorescence Quantum Yield of Two Fluorescein-Amino Acid-Based Compounds in Different Organic Solvents and Gold Colloidal Suspensions

“…In addition, the relative quantum yield of fluorescence was determined for both compounds; the results are presented in Figure 5a as a function of the dielectric constant of the solvents. However, the φ values for compounds 1 and 2 and fluorescein in THF, acetonitrile, and DMSO were low, in agreement with the results of other studies of fluorescein and its derivatives [2,6,12,18]. The decreases of φ values for fluorescein derivatives have been reported and attributed to the photoinduced electron transfer due to a group linked to the fluorophore of the xanthene or phenyl ring [42].…”

“…One of the most commonly yellowish-green emitting dyes used for the preparation of advanced molecular probes applied in biological, toxicological, biomedical, and environmental studies is fluorescein [1][2][3][4]. It is a very versatile dye due to its attractive photophysical properties, such as high extinction coefficients, high fluorescence quantum yield (φ), biocompatibility and low cost [5][6][7].…”

Superconducting nanowire single photon detectors operating at temperature from 4 to 7 K

“…To characterize the single photon detectors, we used different laser diodes emitting at 400 nm, 515 nm, 642 nm, 670 nm, 785 nm and 1550 nm. The wavelength range of 400 -700 nm is significant for fluorescence microscopy [32,33] and for studying celestial objects from space and ground-based observatories. Many high purity III-V QDs emit at ∼ 800 nm [34,35] likewise quantum memories based on electromagnetically induced transparency in Rubidium cells [36].…”

Using SERS Tags to Image the Three‐Dimensional Structure of Complex Cell Models

“…An alternative method comprises the use of organic dyes or fluorescent proteins to label cells for short periods of time, normally ranging from 1 to 4 cell divisions, both of which are better tolerated and also offer more flexibility in the choice of cells and fluorophores to be used 14. Regarding the physical limitations of fluorescence detection, whereas high levels of resolution and sensitivity can be achieved in living cells organized in monolayer structures, upon increasing the thickness in the z‐axis various limitations arise, including a) inability of the light source to penetrate the sample and reach the fluorophore, b) inability of the emitted light to penetrate the sample and reach the detector, c) limitation in the fluorophores that can be used due to biological tissue absorption of light with wavelength in the visible spectrum, and d) overlapping signals due to broad emission bands 15,16. Thus, when long‐term cell cultures which may suffer from fluorophore chemical degradation or signal loss are considered, alternative methods to fluorescence are needed 17…”