Field-deployable modular absorbance analysis platform with standardized electronics for point-of-care diagnostics

The growing demand for personalized healthcare and real-time patient monitoring has accelerated the advancement of point-of-care testing (POCT) technologies. Among available analytical methods, the enzyme-linked immunosorbent assay (ELISA) is well-known for its high sensitivity, selectivity, and operational simplicity. However, conventional ELISA systems remain poorly suited for portable use because they require complex optical components and stable power supplies. To overcome these limitations, we developed a modular absorbance analysis platform (MAAP) that simplifies ELISA system by reconfiguration its core functions into standardized, task-specific modules. The platform integrates a white light source, intensity regulator, optical sensor, display, and battery module, enabling compact and field-deployable ELISA operation. As proof of concept, a polydimethylsiloxane (PDMS)-based bioreactive chamber was fabricated to perform a competitive immunoassay for C-peptide, an insulin secretion biomarker. Following disassembly, transport, and reassembly of the modular system, colorimetric signal detection was performed on-site. C-peptide was quantitatively analyzed within a defined concentration range with a measurable detection limit, demonstrating both analytical performance and practical applicability. These results highlight the potential of the proposed modular ELISA platform as a versatile and scalable solution for POCT diagnostics.