Rapid colorimetric detection of phthalates using DNA-modified gold nanoparticles

Phthalates, also called phthalic acid esters (PAEs), are well-known endocrine-disrupting chemicals (EDCs) that have been detected in residential and occupational environments. In the present study, a simple and rapid method is proposed for the detection of phthalates (diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP)) based on DNA-modified gold nanoparticles (AuNPs). In the presence of phthalates, the DNA-modified AuNPs formed aggregates. Thus, a visible color change from red to blue and an increase in the absorption ratio with an increasing concentration of phthalates were observed. The limits of detection (LODs) for DEP, DBP, and DEHP were determined to be 0.026 ppm, 0.077 ppm, and 0.144 ppm, respectively. The sensitivity and selectivity test results showed that the DNA-modified AuNPs were able to detect phthalates. The proposed DNA-modified AuNPs (aptamer-E, aptamer-B and aptamer-H) are expected to have potential applications in environmental fields.