MWCNT Buckypaper as Electrochemical Sensing Platform: A Rapid Detection Technology for Phthalic Acid Esters in Solutions

Phthalic Acid Esters (PAEs) are a well-known ubiquitous environmental pollutant that holds a significant threat to human health. Despite their harmful effects, the constant use of PAEs in producing flexible plastic products has awakened society's great concern, especially with their ability to leach, migrate, or evaporate from plastics to the surrounding. Therefore, rapid and easy monitoring of the PAEs presence in different environments is crucial. This study introduces a rapid PAE detection technique that shows potential for overcoming the limitations of already existing PAE detecting methods. This novel PAE sensing platform (buckypaper) is developed using highly conducting Multi-Walled Carbon Nanotubes (MWCNT). The buckypaper adsorbs PAEs in solutions and decreases its conductivity. This conductivity decrement is detected using the Nyquist and Bode plots obtain from three-electrode Electrochemical Impedance Spectroscopy (EIS) analysis. This novel method has shown that it has the potential to distinguish DEHP (di-(2-ethylhexyl) phthalate), DPHP (di-(2-propylheptyl) phthalate), and DnOP (di-octyl phthalate) from other aromatic molecules such as toluene, xylene, naphthalene, and bisphenol-A. Moreover, the developed buckypaper is sensitive down to 1000 (v/v) ppm concentrated PAEs in methanol solutions at room temperature, which exhibits the potential of using this platform as an in-situ and real-time PAE detecting sensor.

Automated summary

Phthalic Acid Esters (PAEs) are a common environmental pollutant that poses a significant threat to human health. The constant use of PAEs in producing plastic products has raised concerns due to their ability to leach into the environment. This study introduces a rapid PAE detection technique using a novel sensing platform called buckypaper, which shows potential for overcoming the limitations of existing methods.