Faculty of Physics - University of Bucharest

UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2026-06-12 0:10

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Conference: Bucharest University Faculty of Physics 2026 Meeting

Title:

Resin-3D-Printed Microfluidic Disc with PMMA/Hydrogel-Immobilized Organic Dye Sensors and Calibration-Aware Colorimetric Readout for Low-Volume Urine and Saliva Screening

Authors:

Stefan Caramizoiu1,3, Ana-Maria Iordache1, Ana-Maria Florea1,2, Bogdan-Ionut Bita1,2, Valentin Barna3, Stefan-Marian Iordache1

^*
Affiliation:

1) Optospintronics Department, National Institute of Research and Development for Optoelectronics - INOE 2000, 409 Atomistilor Street, Magurele, 077125, Romania;

2) Department of Electricity, Solid-State Physics and Biophysics, Faculty of Physics, University of Bucharest, 405 Atomistilor Street, P.O. Box MG-11, 077125 Magurele, Romania;

3) Department of Structure of Matter, Atmospheric and Earth Physics, Astrophysics, Faculty of Physics, University of Bucharest, 405 Atomistilor Street, P.O. Box MG-11, 077125, Magurele, Romania.

E-mail

stefan.caramizoiu@inoe.ro; stefan.iordache@inoe.ro

Keywords:

3d printing,organic dyes, urine and saliva screening, pmma/hydrogel matrix

Abstract:

The use of microfluidic test cartridges combined with colorimetric sensing enables a low-cost, non-invasive approach for screening biofluids such as urine and saliva. However, quantitative interpretation remains challenging due to variations between devices, illumination conditions, and non-uniform interactions between samples and sensing surfaces. The implementation of a 3D-printed resin microfluidic cartridge incorporating a microchannel network provides multiple reaction chambers, enabling parallel colorimetric analysis from a minimal sample volume. The biofluid sample is introduced into the disc and distributed through integrated microchannels toward the reaction chambers, ensuring reproducible contact with the polymeric sensing regions. By employing a PMMA/hydrogel matrix, the colorimetric dyes are immobilized, leading to improved handling, enhanced stability, and highly repeatable colorimetric responses at sub-percent sensitivity levels. To ensure compatibility and reproducibility across all measurements, standardized colorimetric calibration is performed using reference colour patterns under controlled illumination conditions. This strategy integrates rapid prototyping of microfluidic discs, functional polymeric colorimetric sensors, and standardized calibration methodologies, providing a robust and scalable platform for multiplexed screening panels in urine and saliva analysis. Future developments may further expand the sensing capabilities toward broader screening applications and clinically relevant biofluid analysis scenarios.

Acknowledgement:

The authors were supported by the Core Program with the National Research Development and Innovation Plan 2022-2027, carried out with the support of MER, project no. PN 23 05.