Multilayer Paper Analytical Device for Low-Cost Pharmaceutical Detection

The patent employs disposable paper analytical devices that are inexpensive, single-use test strips or papers impregnated with reagents. These disposable devices eliminate the need for complex, expensive, reusable analytical equipment while providing sufficient detection accuracy for field use. The paper matrix itself serves as the analytical platform with integrated reagents, making the entire device disposable and eliminating complex cleaning, calibration, and maintenance systems.

The patent extracts and integrates only the essential analytical function into a simple paper-based platform, removing unnecessary complexity from traditional analytical devices. By taking out the core detection capability and embedding it directly into the paper matrix with printed or impregnated reagents, the system achieves accurate detection without requiring complex instrumentations, power supplies, or environmental controls.

The patent segments the analytical process into distinct functional zones on the paper device, including sample application areas, reagent reaction zones, and result detection regions. This segmentation allows simultaneous occurrence of multiple analytical steps (sample preparation, reagent reaction, and detection) across different zones, dramatically reducing total testing time while maintaining precision through zone-specific optimization.

The patent incorporates reagents in preliminary prepared forms directly onto the paper matrix before use. Reagents are pre-impregnated, pre-printed, or pre-loaded into reservoirs on the device, eliminating time-consuming steps of reagent preparation, measurement, and application during actual testing. This preliminary preparation enables rapid deployment and immediate analysis upon sample application.

The paper analytical device is designed to be self-service, requiring no external power sources, instrumentation, or specialized operational expertise. The device performs all necessary functions automatically: sample application triggers reagent reactions through capillary action or diffusion, color changes occur spontaneously based on chemical interactions, and results are directly visible or can be captured with basic imaging. This self-service nature enables operation by anyone with minimal training while maintaining analytical precision.

The patent replaces complex mechanical and electronic systems with simple chemical and optical phenomena. Instead of using powered analyzers, pumps, or sensors, the device relies on passive capillary flow for sample and reagent movement, spontaneous colorimetric or fluorometric reactions for detection, and basic optical reading (even by eye or simple camera) for results. This substitution eliminates the need for power supplies, complex mechanics, and sophisticated electronics while preserving measurement capability.