Fabrication and Optimization of Paper-based Analytical Devices (Pads) for Preliminary Analysis of Sedative-hypnotics
DOI:
https://doi.org/10.48165/iijfmt.2026.24.01.04Abstract
Sedative-hypnotics are frequently encountered in drug-facilitated crimes and overdosage cases due to their rapid pharmacological action, amnesic effects, and ease of administration in beverages or food matrices. Conventional forensic screening techniques such as colour tests and thin-layer chromatography (TLC) remain widely used but comes with limitation including subjectivity, limited sensitivity, and infrastructure dependency. Paper-based analytical devices (PADs) have emerged as promising alternatives offering low-cost, portable, and field-deployable analytical platforms. In the present study, five PAD configurations were fabricated using wax imprinting to generate hydrophobic barriers and hydrophilic microchannels. The devices were systematically optimised by evaluating sample retention efficiency, solvent migration behaviour, reagent-sample interaction, and colour development uniformity. Comparative analysis revealed that channel geometry significantly influenced capillary flow dynamics and analytical performance. Among the tested designs, the PAD incorporating a central rectangular interaction chamber demonstrated superior solvent retention, enhanced colour stability, and improved reproducibility. These devices can be effectively used to detect barbiturates, benzodiazepines, z-drugs, etc. The reaction output can be further interpreted for screening and presumptive examination both in field as well as laboratory. The optimised PAD configuration provides a reliable platform for rapid presumptive screening of sedative-hypnotics and supports the integration of portable colorimetric analysis in forensic field investigations.
Downloads
References
Yagoda, H. (1937). Applications of confined spot tests in analytical chemistry: Preliminary paper. Industrial & Engineering Chemistry, Analytical Edition.
Müller, R. H., & Clegg, D. L. (1949). Analytical Chemistry, 21(9), 1123.
Martinez, A. W., Phillips, S. T., Butte, M. J., & Whitesides, G. M. (2007). Patterned paper as a platform for inexpensive, low-volume, portable bioassays. Angewandte Chemie International Edition, 46(8), 1318–1320. https://doi.org/10.1002/anie.200603817
Carrilho, E., Martinez, A. W., & Whitesides, G. M. (2009). Understanding wax printing: A simple micropatterning process for paper-based microfluidics. Analytical Chemistry, 81(16), 7091–7095. https://doi.org/10.1021/ac901071p
Li, X., Ballerini, D. R., & Shen, W. (2012). A perspective on paper-based microfluidics: Current status and future trends. Biomicrofluidics, 6(1), 011301. https://doi.org/10.1063/1.3687398
Yetisen, A. K., Akram, M. S., & Lowe, C. R. (2013). Paper-based microfluidic point-of-care diagnostic devices. Lab on a Chip, 13(12), 2210–2251. https://doi.org/10.1039/c3lc50169h
Cate, D. M., Adkins, J. A., Mettakoonpitak, J., & Henry, C. S. (2015). Recent developments in paper-based microfluidic devices. Analytical Chemistry, 87(1), 19–41. https://doi.org/10.1021/ac503968p
Das, R., & Mishra, J. (2019). Comparative spectroscopic analysis between Dille–Koppanyi test and Zwikker’s test for the detection of barbiturates in illicit cases. European Journal of Molecular & Clinical Medicine, 6(1), 23–28.
Das, R., & Ballal, S. (2025). Sustainable approaches for alprazolam analysis: Optimization of image colorimetry-based spot tests and quantitative thin layer chromatography (qTLC). In Proceedings of ICONS-2024 (pp. 12–18).
