Paper-Based Assay for Ascorbic Acid Based on the Formation of Ag Nanoparticles in Layer-by-Layer Multilayers

Yuki Tokura, Yukari Moriyama, Yuki Hiruta, Seimei Shiratori

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


A simple, portable, and cost-effective paper-based colorimetric assay is developed for ascorbic acid (AA) with excellent properties, such as fast response, high sensitivity, high selectivity, and good stability. AA is an important nutrient for human life, and adequate quantification of AA is required for controlling the intake of AA for health management. Moreover, point-of-care analysis, which is a simple, easy-to-use, and cost-effective analysis method for unskilled users, has been a focus in the medical and health care fields. We fabricate a colorimetric paper-based assay with poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA) layer-by-layer self-assembly containing silver ions for the point-of-care analysis of AA. The color of the assay is changed from white to yellow and then to dark-brown after immersion in AA solution because of the reduction of silver ions to silver nanoparticles by AA and the localized surface plasmon resonance of the generated silver nanoparticles. The assay shows a fast response to AA of only 60 s and a sensitivity to AA (limit of detection is 0.4 ppm). Furthermore, the colorimetric assay exhibits a high selectivity for AA compared with other compounds contained in human fluid and various drinks. The concentration of AA in various commercial products is quantified by the assay with the same accuracy as high-performance liquid chromatography. The design of the PAH/PAA multilayers containing silver ions for a fast response, highly sensitive, and selective colorimetric assay will contribute to the development of point-of-care analysis for the early detection of diseases as well as controlling the intake of nutrients.

Original languageEnglish
Pages (from-to)241-249
Number of pages9
JournalACS Applied Nano Materials
Issue number1
Publication statusPublished - 2019 Jan 25


  • ascorbic acid
  • colorimetric sensor
  • layer-by-layer
  • paper-based assay
  • silver nanoparticle

ASJC Scopus subject areas

  • General Materials Science


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