Abstract
A selection of aptamers specific for di(2-ethylhexyl) phthalate (DEHP) and development of electrochemical impedance spectroscopy (EIS) aptasensor are described in this paper. The aptamers were selected from an immobilized ssDNA library using the systematic evolution of ligands by exponential enrichment (SELEX). The enrichment was monitored using real-time quantitative PCR (Q-PCR), and the aptamers were identified by high-throughput sequencing (HTS), gold nanoparticles (AuNPs) colorimetric assay, and localized surface plasmon resonance (LSPR). The EIS aptasensor was developed to detect DEHP in water samples. After eight rounds of enrichment, HTS, AuNPs colorimetric assay, and LSPR analysis indicated that four aptamers had higher binding activity, and aptamer 31 had the highest affinity (Kd = 2.26 ± 0.06 nM). The EIS aptasensor had a limit of detection (LOD) of 0.103 pg/mL with no cross-reactivity to DEHP analogs and a mean recovery of 76.07% to 141.32% for detection of DEHP in water samples. This aptamer is novel with the highest affinity and sensitivity.
Highlights
Di(2-ethylhexyl) phthalate (DEHP) is a kind of plasticizer that has toxic effects associated with its action as an androgen antagonist
Selection of Aptamers Specific for di(2-ethylhexyl) phthalate (DEHP) Based on single-strand DNA (ssDNA) Immobilized systematic evolution of ligands by exponential enrichment (SELEX)
A key step for aptamer selection involves monitoring the enrichment of the ssDNA library
Summary
Di(2-ethylhexyl) phthalate (DEHP) is a kind of plasticizer that has toxic effects associated with its action as an androgen antagonist. DEHP is widely used as an additive to food packaging materials, which leads to its accumulation in food exceeding the national standards for its ability to migrate from food packaging to drinking water [3,4]. It is necessary to continuously and effectively monitor the residue of DEHP. The methods for DEHP detection include analytical instrumentation, immunoassay, and biosensor. The commonly applied methods use analytical separation instruments. The limit of detection (LOD) of these methods is 0.05–10 mg/L for high-performance liquid chromatography (HPLC) [5,6,7], 0.01–0.1 ng/mL for high performance liquid chromatography–mass spectrometry (HPLC–MS) [8], 0.008–356 μg/mL for gas chromatography–mass spectrometry (GC–MS) [9], Molecules 2020, 25, 747; doi:10.3390/molecules25030747 www.mdpi.com/journal/molecules
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call