A simple paper-based analytical device using UV resin screen-printing for the determination of ammonium in soil

Abstract

A convenient and low cost paper-based analytical device (PAD) was developed using an inexpensive UV resin with a screen-printing method for measuring ammonium in soil.

Underground Ink: Printed Electronics Enabling Electrochemical Sensing in Soil

“…An alternative method involves utilizing colorimetry to differentiate analyte concentrations based on light intensity [27,90]. Thongkam et al developed a screen-printed paper-based analytical device (PAD) for detecting ammonium in soil by employing Berthelot's reaction on the PAD [91]. The color intensity is linearly related to the ammonium concentration in soil.…”

A simple epoxy resin screen-printed paper-based analytical device for detection of phosphate in soil

“…In contrast, screen-printing is comparatively simple, fast, and inexpensive, requiring no elaborate equipment. Screen printing of polymer solutions such as polydimethylsiloxane (PDMS), 29,30 polystyrene, 31 and UV resin 32 have been developed for μPAD fabrication. However, heat source or UV lamp are required for curing process of PDMS and UV resins, and toluene, which is a toxic solvent, is required to dissolve polystyrene.…”

A newly designed sticker-plastic sheet platform and smartphone-based digital imaging for protein assay in food samples with downscaling Kjeldahl digestion

“…It would be of interest to apply colorimetric determination for ammonia/ammonium produced from Kjeldahl digestion as an alternative to the conventional titration. Various reagents for the purpose may be available including indophenol or Berthelot (alkali-phenol), [19][20][21] Nessler (potassium mercuric iodide in alkaline solution), 10,19,22,23 ninhydrin, 24,25 o-phthalaldehyde, 26,27 and acetyl acetone. 28,29 Among those, Nessler's reagent is a commonly used reagent in environmental laboratories.…”

“…The commercially available microwell plates have been great platforms for chemical and biochemical assays due to their easy integration with scanners, smartphones or digital cameras. Various fabrication methods for downscaling chemical analysis platforms have been reported, including microzone plates, 35,37,38 spot test arrays, 39,40 and microuidic based devices, [41][42][43][44][45][46] aiming to lower sample and reagent volumes, to help in minimizing wastes.…”