Journal: bioRxiv

Article Title: Design, Fabrication, and Theoretical Investigation of a Cost-Effective Laser Printing Based Colorimetric Paper Sensor for Non-Invasive Glucose and Ketone Detection

doi: 10.1101/2021.09.23.461386

Figure Lengend Snippet: Schematic depicting the detailed procedure followed for laser-printing the device designs onto a Whatman grade-1 filter paper. From a through f, the filter paper was carefully placed atop an A4-size sheet, and the premade designs were printed on to the filter paper following symmetry and proper alignment protocol. The substrates were then assiduously peeled-off from the A4 sheet, and sandwiched between a hot-plate and a copper block, both pre-heated to 180 °C, to ensure thorough melting of the printer-ink. After heating the substrate for circa. 40 minutes, the devices were carefully removed from the heater and allowed to cool down. The devices were stored in an inert ambiance until use, to ensure negligible contamination from dust and other foreign objects. Subsequently, specific reagents pertaining to glucose and ketone assays were deposited in the designated zones of the respective devices, and were allowed to dry. The final devices were used for the successful estimation of glucose and ketone contents in the urine samples.

Article Snippet: Given the non-linear relationship exhibited by κ (ξ) and φ (ξ) in the above equation, several correlations have been proposed to obtain a physically relevant solution to the Richards’ equation. ( ; ; ; ) One such widely accepted formulation is that proposed by van Genuchten, ( ; ) and is represented as follows ( ): where, α , q , and l denote the van Genutchen parameters, and for the Whatman grade-1 filter paper used in the present work, these values are available in the literature ( ; ; ). denotes the normalized saturation, represents the pressure head, , K s is the value of permeability at complete saturation (i.e. S n = 1), and .

Techniques: Blocking Assay