Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical...

Area of Science:

• Environmental Science
• Biotechnology
• Analytical Chemistry

Background:

• Phthalic acid esters (PAEs) are significant persistent organic pollutants with increasing congener diversity.
• Detecting PAEs as a group is crucial for environmental monitoring.
• Selecting DNA aptamers for hydrophobic small molecules like PAEs presents unique challenges.

Purpose of the Study:

• To develop a bead-based method for selecting group-specific DNA aptamers against phthalic acid esters (PAEs).
• To enable the development of biosensors for the detection of hydrophobic small molecules.
• To provide insights into aptamer discovery for challenging targets.

Main Methods:

• Synthesis and immobilization of an amino group functionalized dibutyl phthalate (DBP-NH2) on epoxy-activated agarose beads.
• Selection of group-specific DNA aptamers using a bead-based approach.
• Quantification of aptamer dissociation constants via quantitative PCR and magnetic separation.
• Assessment of aptamer affinity and selectivity using competitive assays.
• Fabrication and testing of an electrochemical aptasensor for bis(2-ethylhexyl) phthalate detection.

Main Results:

• Successful selection of DNA aptamers capable of binding to the phthalic ester group.
• Determination of aptamer affinities and selectivity for various PAEs.
• Demonstration of an electrochemical aptasensor for ultrasensitive and selective bis(2-ethylhexyl) phthalate detection.
• The developed method facilitates aptamer discovery for hydrophobic small molecules.

Conclusions:

• A robust bead-based method for selecting group-specific DNA aptamers to PAEs was established.
• The study highlights the potential of aptamers in detecting persistent organic pollutants.
• The developed aptasensor offers a sensitive and selective platform for environmental monitoring of PAEs.