T-shirt ink for one-step screen-printing of hydrophobic barriers for 2D- and 3D-microfluidic paper-based analytical devices

Jirayu Sitanurak; Nutnaree Fukana; Thinnapong Wongpakdee; Yanisa Thepchuay; Nuanlaor Ratanawimarnwong; Taweechai Amornsakchai; Duangjai Nacapricha

doi:10.1016/j.talanta.2019.120113

T-shirt ink for one-step screen-printing of hydrophobic barriers for 2D- and 3D-microfluidic paper-based analytical devices

Talanta. 2019 Dec 1:205:120113. doi: 10.1016/j.talanta.2019.120113. Epub 2019 Jul 2.

Authors

Jirayu Sitanurak¹, Nutnaree Fukana¹, Thinnapong Wongpakdee¹, Yanisa Thepchuay¹, Nuanlaor Ratanawimarnwong², Taweechai Amornsakchai³, Duangjai Nacapricha⁴

Affiliations

¹ Flow Innovation-Research for Science and Technology Laboratories (Firstlabs), Bangkok, Thailand; Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.
² Flow Innovation-Research for Science and Technology Laboratories (Firstlabs), Bangkok, Thailand; Department of Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok, 10110, Thailand.
³ Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Phuttamonthon 4 Road, Salaya, Nakhon Pathom, 73170, Thailand.
⁴ Flow Innovation-Research for Science and Technology Laboratories (Firstlabs), Bangkok, Thailand; Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand. Electronic address: dnacapricha@gmail.com.

PMID: 31450420
DOI: 10.1016/j.talanta.2019.120113

Abstract

This work presents the use of polyvinyl chloride (PVC) fabric ink, commonly employed for screening t-shirts, as new and versatile material for printing hydrophobic barrier on paper substrate for microfluidic paper-based analytical devices (μPADs). Low-cost, screen-printing apparatus (e.g., screen mesh, squeegee, and printing table) and materials (e.g. PVC ink and solvent) were employed to print the PVC ink solution onto Whatman filter paper No. 4. This provides a one-step strategy to print flow barriers without the need of further processing except evaporation for 3-5 min in a fume hood to remove the solvent. The production of the single layer μPADs is reasonably high with up to 77 devices per screening with 100% success rate. This method produces very narrow fluidic channel 486 ± 14 μm in width and hydrophobic barrier of 642 ± 25 μm thickness. Reproducibility of the production of fluidic channels and zones is satisfactory with RSDs of 2.9% (for 486-μm channel, n = 10), 3.7% (for 2-mm channel, n = 50) and 1.5% (for 6-mm diameter circular zone, n = 80). A design of a 2D-μPAD produced by this method was employed for the colorimetric dual-measurements of thiocyanate and nitrite in saliva. A 3D-μPADs with multiple layers of ink-screened paper was designed and constructed to demonstrate the method's versatility. These 3D-μPADs were designed for gas-liquid separation with in-situ colorimetric detection of ethanol vapor on the μPADs. The 3D-μPADs were applied for direct quantification of ethanol in beverages and highly colored pharmaceutical products. The printed barrier was resistant up to 8% (v/v) ethanol without liquid creeping out of the barrier.

Keywords: Ethanol; Fabric ink barrier; Nitrite; Paper-based analytical device; Saliva; Thiocyanate.