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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.

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Cleavage of the QD-dye linker by the activity of the analyte causes a disruption of FRET, and a subsequent alteration of the QD-dye emission ratio.
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sensors-15-13028-f002: Cleavage of the QD-dye linker by the activity of the analyte causes a disruption of FRET, and a subsequent alteration of the QD-dye emission ratio.

Mentions: The strategy of donor-acceptor spatial modulation has been used to create a ratiometric response, which is essentially a color change as the reporting mechanism rather than emission intensity modulation. An early demonstration concerned the measurement of proteolytic enzyme activity. Here, a QD is functionalized with a peptide linker that is terminated with an energy accepting fluorescent dye. Due to a finite FRET efficiency, emission can be observed from both the QD donor and dye acceptor. However, the ratio of the intensities of the two chromophores is altered by the addition of an analyte, which cleaves the linker causing the dye to diffuse away from the QD. As a result, nanocrystal emission becomes more dominant (Figure 2).


QD-Based FRET Probes at a Glance.

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

Cleavage of the QD-dye linker by the activity of the analyte causes a disruption of FRET, and a subsequent alteration of the QD-dye emission ratio.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-13028-f002: Cleavage of the QD-dye linker by the activity of the analyte causes a disruption of FRET, and a subsequent alteration of the QD-dye emission ratio.
Mentions: The strategy of donor-acceptor spatial modulation has been used to create a ratiometric response, which is essentially a color change as the reporting mechanism rather than emission intensity modulation. An early demonstration concerned the measurement of proteolytic enzyme activity. Here, a QD is functionalized with a peptide linker that is terminated with an energy accepting fluorescent dye. Due to a finite FRET efficiency, emission can be observed from both the QD donor and dye acceptor. However, the ratio of the intensities of the two chromophores is altered by the addition of an analyte, which cleaves the linker causing the dye to diffuse away from the QD. As a result, nanocrystal emission becomes more dominant (Figure 2).

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