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

Abstract

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.

A ninety-six well plate as headspaces with moist starch indicator paper as a cover for the determination of ascorbic acid by iodate oxidation and formation of volatile iodine

“…Table 3 lists reported studies for ascorbic acid analysis using PADs with various colorimetric detection methods. 35–37 The analytical features of the cited work are listed for comparison with this study. This work uses a simple chemical reaction, comprising excess KIO 3 and acetic acid to generate volatile iodine, which is proportional to the ascorbic acid content in the sample solution.…”

“…This is a new headspace colorimetric detection method of iodine, whereas other studies employ liquid phases, e.g. , spot test, 35 immersion into a sample solution, 36 and dipstick assay. 37 These methods also did not separate iodine before detection, and thus can be affected by the matrix of the sample.…”

“…29 Various instrumental methods have been employed for ascorbic acid determination, such as high-performance liquid chromatography (HPLC), 30 electrochemical analysis, 31 capillary electrophoresis, 32 fluorescence, 33 and chemiluminescence. 34 Recently, various paper-based analytical devices (PADs) with simple colorimetric detection involving a spot test, 35 immersion in sample solution, 36 and dipstick assay 37 have been applied for ascorbic acid analysis.…”

Cobalt Oxyhydroxide Nanoflakes/Cellulose Composite Membranes with Enhanced Detection of Ascorbic Acid

“…Several nanomaterials have been developed for AA detection recently. 4,5 However, most of the nanomaterials in these reported works were inevitably fabricated via complicated, toxic, and time-consuming routes. Compared to these methods, the method using CoOOH nanoflakes is supposed to solve this problem well, and it also had been intensively explored for AA detection.…”

Hexagonal CoOOH Nanoflakes Synthesized From Three-Dimensional Cellulose Membrane Matrix With Enhanced Detection of Ascorbic Acid

“…Recently, there are a lot of nanomaterials have been developed for AA detection. (Han et al 2019;Tokura et al 2019) However, the fabrication method of most nanomaterials in these reported works were inevitably faced complicated, toxic, and time-consuming routes. Compared to these methods, CoOOH nano akes can be used to solve this problem well, and it also has been intensively explored for AA detection.…”