Patterned Porous Bioassay Devices for Remote Quantitative Analysis
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Solution Overview
Problem
Conventional bioassay devices are unsuitable for remote locations due to their large size, high cost, and requirement for trained personnel and significant sample volumes, particularly challenging in developing countries or emergency situations, and existing alternatives like microfluidic devices often require pumps and external detectors.
Innovation Solution
A bioassay device featuring a porous hydrophilic medium with embedded fluid impervious barriers that define channels and assay regions, allowing for capillary fluid transport and visible analyte detection using assay reagents, which can be fabricated using photolithography or soft lithography, enabling low-cost, portable, and simple multiplexed bioassays with minimal equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional laboratory instruments are used for quantitative measurements of biological samples, then measurement precision is improved, but device complexity and cost increase, making them unsuitable for remote locations
Solution Approach 1:
The patent extracts the essential measurement function from complex laboratory instruments and implements it using simple patterned paper devices. The paper devices contain integrated reagent patterns that perform specific biochemical measurements (glucose, protein, pH, etc.) without requiring external equipment, thereby achieving quantitative measurement capability while eliminating instrument complexity
Solution Approach 2:
The patterned paper devices are designed to be self-contained and self-operating. The paper matrix itself serves as the reaction platform, fluid transport medium, and detection substrate. Reagents are pre-patterned on the paper and automatically mix with sample fluids through capillary action, eliminating the need for external pumps, mixers, or detectors
2Measurement precision
If conventional laboratory instruments are used for quantitative measurements, then measurement precision is improved, but the volume of biological samples required increases, making them unsuitable for situations with limited sample availability
Solution Approach 1:
The patent applies local quality by creating distinct functional zones on the paper device with different reagent concentrations and distributions. Each measurement zone contains reagents optimized for specific analytes, allowing precise local measurements with minimal sample volumes. The patterned reagent distribution ensures that each region performs its specific measurement function efficiently
Solution Approach 2:
The patent utilizes the porous structure of paper as the measurement matrix. The porous paper matrix allows rapid wicking and distribution of small sample volumes across multiple measurement zones. The high surface area-to-volume ratio of the porous structure enables efficient analyte-reagent interaction, achieving precise measurements with minimal sample requirements
3Ease of operation
If dipsticks are used for bioassays, then ease of operation is improved, but manufacturing cost increases and sample volume requirements increase to about 5 mL
Solution Approach 1:
The patent segments the dipstick into multiple functional zones with different reagent patterns on a single paper substrate. Each zone performs a specific measurement function (glucose, protein, pH, etc.), allowing multiplexed measurements in a single device. This segmentation enables cost-effective manufacturing by printing reagents directly onto paper in predetermined patterns, eliminating the need for multiple separate dipsticks
Solution Approach 2:
The patterned paper device achieves multi-functionality by integrating multiple measurement capabilities into a single device. The paper matrix serves universal functions as fluid transport medium, reaction substrate, and detection platform for various analytes. This universality reduces manufacturing costs by consolidating multiple functions into one device while maintaining operational simplicity
4Measurement precision
If microfluidic devices are used for biological screening, then measurement precision is improved, but device complexity increases due to requirements for pumps and external detectors
Solution Approach 1:
The patent replaces mechanical fluid handling systems (pumps, valves, channels) with passive capillary-driven flow in porous paper. The porous paper matrix provides automatic fluid distribution through capillary forces, eliminating the need for external pumps and complex microfluidic channels while maintaining precise fluid control for biological screening applications
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device provides a cost-effective, portable, and easy-to-use platform for analyzing biological fluids, capable of detecting analytes like glucose, protein, and other biomarkers with minimal sample volume, suitable for remote settings and emergency situations, while maintaining accuracy and sensitivity.
Implementation Method 1
a porous hydrophilic medium capable of transporting fluids by capillary action
Implementation Method 2
a fluid impervious barrier embedded in the porous hydrophilic medium, said barrier defining a channel terminating in one or more detection regions
Implementation Method 3
The porous hydrophilic medium is treated to provide a visible indication of an analyte present in a fluid
Data Source
AI summary
Embodiments of the invention provide lateral flow and flow-through bioassay devices based on patterned porous media, methods of making same, and methods of using same. Under one aspect, an assay device includes a porous, hydrophilic medium; a fluid impervious barrier comprising polymerized photoresist, the barrier substantially permeating the thickness of the porous, hydrophilic medium and defining a boundary of an assay region within the porous, hydrophilic medium; and an assay reagent in the assay region.