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Dopamine-functionalized InP/ZnS quantum dots as fluorescence probes for the detection of adenosine in microfluidic chip.

Ankireddy SR, Kim J - Int J Nanomedicine (2015)

Bottom Line: Microbeads are frequently used as solid supports for biomolecules such as proteins and nucleic acids in heterogeneous microfluidic assays.The photoluminescence (PL) intensity of the QDs-DA is quenched by Zn(2+) because of the strong coordination interactions.In the presence of adenosine, Zn(2+) cations preferentially bind to adenosine, and the PL intensity of the QDs-DA is recovered.

View Article: PubMed Central - PubMed

Affiliation: Department of chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-Do, South Korea.

ABSTRACT
Microbeads are frequently used as solid supports for biomolecules such as proteins and nucleic acids in heterogeneous microfluidic assays. Chip-based, quantum dot (QD)-bead-biomolecule probes have been used for the detection of various types of DNA. In this study, we developed dopamine (DA)-functionalized InP/ZnS QDs (QDs-DA) as fluorescence probes for the detection of adenosine in microfluidic chips. The photoluminescence (PL) intensity of the QDs-DA is quenched by Zn(2+) because of the strong coordination interactions. In the presence of adenosine, Zn(2+) cations preferentially bind to adenosine, and the PL intensity of the QDs-DA is recovered. A polydimethylsiloxane-based microfluidic chip was fabricated, and adenosine detection was confirmed using QDs-DA probes.

No MeSH data available.


Fluorescence intensity variations of QDs as a function of time after injection of 10 µmol l−1 Zn2+ solution.Abbreviations: QDs, quantum dots; MPA, mercaptopropionic acid; MUA mer captoundecanoic acid; min, minutes; DI, deionized.
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f7-ijn-10-121: Fluorescence intensity variations of QDs as a function of time after injection of 10 µmol l−1 Zn2+ solution.Abbreviations: QDs, quantum dots; MPA, mercaptopropionic acid; MUA mer captoundecanoic acid; min, minutes; DI, deionized.

Mentions: Figure 7 shows the fluorescence intensity variations of the QDs as a function of time after 1.5 mL injection of 10 µmol L−1 Zn2+ and adenosine solution. The flow rate was kept at 50 µL/min using a syringe pump. After addition of 10 µmol L−1 Zn2+, the PL intensity of the QDs-DA gradually decreased within 30 minutes and the fluorescence was significantly recovered by the addition of 10 µmol L−1 adenosine. This experiment results also correlated with fluorescence spectra. The PL intensity was quenched by ~60%–65% by electron transfer from the QDs to the Zn2+ cation; 85% of the PL intensity was recovered in the case of beads-QDs-MPA-DA and 75% in the case of beads-QDs-MUA-DA after addition of adenosine, as a result of preferential binding of Zn2+ to adenosine. The figure also shows that for a shorter chain length between Zn2+ and the QDs (MPA), PL quenching was faster. The recovery of PL intensity was higher for a shorter chain length and vice versa. The experiment was repeated three times, with the fluorescence intensity vs time expressed as the mean ± standard deviation, as shown in Figure 7.


Dopamine-functionalized InP/ZnS quantum dots as fluorescence probes for the detection of adenosine in microfluidic chip.

Ankireddy SR, Kim J - Int J Nanomedicine (2015)

Fluorescence intensity variations of QDs as a function of time after injection of 10 µmol l−1 Zn2+ solution.Abbreviations: QDs, quantum dots; MPA, mercaptopropionic acid; MUA mer captoundecanoic acid; min, minutes; DI, deionized.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554435&req=5

f7-ijn-10-121: Fluorescence intensity variations of QDs as a function of time after injection of 10 µmol l−1 Zn2+ solution.Abbreviations: QDs, quantum dots; MPA, mercaptopropionic acid; MUA mer captoundecanoic acid; min, minutes; DI, deionized.
Mentions: Figure 7 shows the fluorescence intensity variations of the QDs as a function of time after 1.5 mL injection of 10 µmol L−1 Zn2+ and adenosine solution. The flow rate was kept at 50 µL/min using a syringe pump. After addition of 10 µmol L−1 Zn2+, the PL intensity of the QDs-DA gradually decreased within 30 minutes and the fluorescence was significantly recovered by the addition of 10 µmol L−1 adenosine. This experiment results also correlated with fluorescence spectra. The PL intensity was quenched by ~60%–65% by electron transfer from the QDs to the Zn2+ cation; 85% of the PL intensity was recovered in the case of beads-QDs-MPA-DA and 75% in the case of beads-QDs-MUA-DA after addition of adenosine, as a result of preferential binding of Zn2+ to adenosine. The figure also shows that for a shorter chain length between Zn2+ and the QDs (MPA), PL quenching was faster. The recovery of PL intensity was higher for a shorter chain length and vice versa. The experiment was repeated three times, with the fluorescence intensity vs time expressed as the mean ± standard deviation, as shown in Figure 7.

Bottom Line: Microbeads are frequently used as solid supports for biomolecules such as proteins and nucleic acids in heterogeneous microfluidic assays.The photoluminescence (PL) intensity of the QDs-DA is quenched by Zn(2+) because of the strong coordination interactions.In the presence of adenosine, Zn(2+) cations preferentially bind to adenosine, and the PL intensity of the QDs-DA is recovered.

View Article: PubMed Central - PubMed

Affiliation: Department of chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-Do, South Korea.

ABSTRACT
Microbeads are frequently used as solid supports for biomolecules such as proteins and nucleic acids in heterogeneous microfluidic assays. Chip-based, quantum dot (QD)-bead-biomolecule probes have been used for the detection of various types of DNA. In this study, we developed dopamine (DA)-functionalized InP/ZnS QDs (QDs-DA) as fluorescence probes for the detection of adenosine in microfluidic chips. The photoluminescence (PL) intensity of the QDs-DA is quenched by Zn(2+) because of the strong coordination interactions. In the presence of adenosine, Zn(2+) cations preferentially bind to adenosine, and the PL intensity of the QDs-DA is recovered. A polydimethylsiloxane-based microfluidic chip was fabricated, and adenosine detection was confirmed using QDs-DA probes.

No MeSH data available.