Binding of uranyl ion by a DNA aptamer attached to a solid support

Area of Science:

• Biotechnology
• Materials Science
• Environmental Chemistry

Background:

• Uranium (UO2(2+)) is a critical element for nuclear energy.
• Efficient and economical methods for uranium recovery, especially from dilute sources like seawater, are highly sought after.
• DNA aptamers offer high specificity and affinity for target molecules.

Purpose of the Study:

• To develop and characterize uranyl ion-specific DNA aptamer-conjugated aminopolystyrene (aminoPS) resins.
• To evaluate the uranium uptake capacity and binding affinity of these modified resins.
• To explore the potential of these resins for economical uranium recovery from seawater.

Main Methods:

• Conjugation of a UO2(2+)-specific DNA aptamer to aminopolystyrene (aminoPS) resins using sulfo-SMCC crosslinking.
• Measurement of the uranyl uptake capacity of the aptamer-conjugated resins.
• Determination of binding constants (dissociation constant Kd(app) and formation constant Kf) under specific conditions (pH 8.01, 21 mM bicarbonate ion).

Main Results:

• The aptamer-conjugated aminoPS resins exhibited a uranium complexation capacity of approximately 0.63 μg of uranium per gram of resin.
• The results indicate that the immobilized DNA aptamers effectively bind uranyl ions.
• Binding affinity was quantified with an apparent dissociation constant (Kd(app)) of ~84.6 pM and a log formation constant (log Kf) of ~22.9.

Conclusions:

• Modification of resins with DNA aptamers significantly enhances uranyl-binding ability.
• The developed aptamer-conjugated resins show high efficiency and strong affinity for uranyl ions.
• This approach holds promise for the economical recovery of uranium from seawater.