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QD-Based FRET Probes at a Glance.

Shamirian A, Ghai A, Snee PT - Sensors (Basel) (2015)

Bottom Line: The unique optoelectronic properties of quantum dots (QDs) give them significant advantages over traditional organic dyes, not only as fluorescent labels for bioimaging, but also as emissive sensing probes.They may also function as ratiometric, or "color-changing" probes.An overview of early works, recent advances, and various models of QD-FRET sensors for the measurement of pH and oxygen, as well as the presence of metal ions and proteins such as enzymes, are also provided.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607-7061, USA. ashami2@uic.edu.

ABSTRACT
The unique optoelectronic properties of quantum dots (QDs) give them significant advantages over traditional organic dyes, not only as fluorescent labels for bioimaging, but also as emissive sensing probes. QD sensors that function via manipulation of fluorescent resonance energy transfer (FRET) are of special interest due to the multiple response mechanisms that may be utilized, which in turn imparts enhanced flexibility in their design. They may also function as ratiometric, or "color-changing" probes. In this review, we describe the fundamentals of FRET and provide examples of QD-FRET sensors as grouped by their response mechanisms such as link cleavage and structural rearrangement. An overview of early works, recent advances, and various models of QD-FRET sensors for the measurement of pH and oxygen, as well as the presence of metal ions and proteins such as enzymes, are also provided.

Show MeSH
Coupling fluorescein and TAMRA dyes to the surfaces of Fe2O3 nanoparticles creates a FRET pair between the two chromophores to produce a ratiometric emission spectrum as a function of pH.
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sensors-15-13028-f011: Coupling fluorescein and TAMRA dyes to the surfaces of Fe2O3 nanoparticles creates a FRET pair between the two chromophores to produce a ratiometric emission spectrum as a function of pH.

Mentions: There is a significant level of interest in the synthesis of nanomaterials that are simultaneously fluorescent and magnetic. Unfortunately, some basic properties of semiconductor photophysics generally dictate that magnetic materials have fast de-excitation pathways that prevent fluorescence. Hence, there is a bifurcation in research where magnetic semiconductor nanomaterials are generally only used for MRI contrast agents whereas fluorescent quantum dots are used for visible light imaging. Our group recently addressed this issue by coating Fe2O3 nanocrystals [123] with fluorescein dye to make a magnetic nanomaterial that functioned as a pH sensor [18]. Recently we added another dimension to this where fluorescein and amine-functional carboxytetramethylrhodamine (TAMRA) were both conjugated to the surface of magnetic iron oxide nanomaterials. As shown in Figure 11, the system responds ratiometrically to a change in pH which is fully calibratable. There is a FRET interaction between the dye coupled chromophores as evident from the PLE spectrum of the TAMRA dye which showed fluorescein-like features. Furthermore, we can attach hundreds of dyes per dot [30], which mitigates photobleaching of the organic chromophores.


QD-Based FRET Probes at a Glance.

Shamirian A, Ghai A, Snee PT - Sensors (Basel) (2015)

Coupling fluorescein and TAMRA dyes to the surfaces of Fe2O3 nanoparticles creates a FRET pair between the two chromophores to produce a ratiometric emission spectrum as a function of pH.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507597&req=5

sensors-15-13028-f011: Coupling fluorescein and TAMRA dyes to the surfaces of Fe2O3 nanoparticles creates a FRET pair between the two chromophores to produce a ratiometric emission spectrum as a function of pH.
Mentions: There is a significant level of interest in the synthesis of nanomaterials that are simultaneously fluorescent and magnetic. Unfortunately, some basic properties of semiconductor photophysics generally dictate that magnetic materials have fast de-excitation pathways that prevent fluorescence. Hence, there is a bifurcation in research where magnetic semiconductor nanomaterials are generally only used for MRI contrast agents whereas fluorescent quantum dots are used for visible light imaging. Our group recently addressed this issue by coating Fe2O3 nanocrystals [123] with fluorescein dye to make a magnetic nanomaterial that functioned as a pH sensor [18]. Recently we added another dimension to this where fluorescein and amine-functional carboxytetramethylrhodamine (TAMRA) were both conjugated to the surface of magnetic iron oxide nanomaterials. As shown in Figure 11, the system responds ratiometrically to a change in pH which is fully calibratable. There is a FRET interaction between the dye coupled chromophores as evident from the PLE spectrum of the TAMRA dye which showed fluorescein-like features. Furthermore, we can attach hundreds of dyes per dot [30], which mitigates photobleaching of the organic chromophores.

Bottom Line: The unique optoelectronic properties of quantum dots (QDs) give them significant advantages over traditional organic dyes, not only as fluorescent labels for bioimaging, but also as emissive sensing probes.They may also function as ratiometric, or "color-changing" probes.An overview of early works, recent advances, and various models of QD-FRET sensors for the measurement of pH and oxygen, as well as the presence of metal ions and proteins such as enzymes, are also provided.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607-7061, USA. ashami2@uic.edu.

ABSTRACT
The unique optoelectronic properties of quantum dots (QDs) give them significant advantages over traditional organic dyes, not only as fluorescent labels for bioimaging, but also as emissive sensing probes. QD sensors that function via manipulation of fluorescent resonance energy transfer (FRET) are of special interest due to the multiple response mechanisms that may be utilized, which in turn imparts enhanced flexibility in their design. They may also function as ratiometric, or "color-changing" probes. In this review, we describe the fundamentals of FRET and provide examples of QD-FRET sensors as grouped by their response mechanisms such as link cleavage and structural rearrangement. An overview of early works, recent advances, and various models of QD-FRET sensors for the measurement of pH and oxygen, as well as the presence of metal ions and proteins such as enzymes, are also provided.

Show MeSH