Colorimetric visualization using polymeric core-shell nanoparticles: Enhanced sensitivity for formaldehyde gas sensors

Jae Jung Park, Yongsoo Kim, Chanmin Lee, Jun Won Kook, Donghyun Kim, Jung Hyun Kim, Ki Seob Hwang, Jun Young Lee

Research output: Contribution to journalArticlepeer-review


Although equipment-based gas sensor systems (e.g., high-performance liquid chromatography) have been widely applied for formaldehyde gas detection, pre-treatment and expensive instrumentation are required. To overcome these disadvantages, we developed a colorimetric sensor based on polymer-based core-shell nanoparticles (PCSNPs), which are inexpensive, stable, and exhibit enhanced selectivity. Spherical and uniform poly(styrene-co-maleic anhydride) (PSMA)/polyethyleneimine (PEI) core-shell nanoparticles were prepared and then impregnated with Methyl Red (MR), Bromocresol Purple (BCP), or 4-nitrophenol (4-NP) to construct colorimetric sensors for formaldehyde gas. The intrinsic properties of these dyes were maintained when introduced into the PCSNPs. In the presence of formaldehyde, the MR, BCP, and 4-NP colorimetric sensors changed to yellow, red, and gray, respectively. The colorimetric response was maximized at a PEI/PSMA ratio of four, likely owing to the high content of amine groups. Effective formaldehyde gas detection was achieved at a relative humidity of 30% using the MR colorimetric sensor, which exhibited a large color change (92%) in 1 min. Advantageously, this stable sensor allowed sensitive and rapid naked-eye detection of low formaldehyde concentrations (0.5 ppm). Hence, this approach is promising for real-time formaldehyde gas visualization and can also be adapted to other colorimetric gas sensor systems to improve sensitivity and simplicity.

Original languageEnglish
Article number998
Issue number5
Publication statusPublished - 2020 May 1

Bibliographical note

Funding Information:
This research was funded by the Korea Environmental Industry and Technology Institute (KEITI) under gran number HR200001, "Patch type diagnosis and management technology for hazardous materials in indoor environment. " Acknowledge any support given which is not covered by the author contribution or funding sections. This may include administrative and technical support, or donations in kind (e.g., materials used for experiments)

Publisher Copyright:
© 2020 by the authors.

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Polymers and Plastics


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