Digital microfluidic system for portable endotoxin detection

Overview

This solution is a portable endotoxin analyzer built on digital microfluidics (DMF) technology, a method that manipulates tiny droplets on arrays of electrodes to perform automated biochemical assays. The system is designed to detect endotoxins, which are fever-inducing byproducts of bacterial contamination that pose serious risks in pharmaceutical manufacturing, water safety, and clinical care (such as dialysis treatment). The platform comprises low-cost disposable cartridges and a compact portable instrument, making it accessible for point-of-use testing without requiring trained operators.

The core value proposition is the combination of clinical-grade sensitivity with consumer-grade simplicity. By integrating dried reagents that are hydrated on demand and an intuitive user interface similar to a pregnancy test, the system eliminates the need for specialized laboratory expertise while delivering reliable quantitative results.

Technical specifications

Key features:

• Digital microfluidic cartridge with cost of goods under $2 per unit, enabling affordable single-use testing
• Portable instrument with cost of goods under $3,000, suitable for deployment in clinical and field settings
• Droplet-mediated Limulus amoebocyte lysate (LAL) assay using one-microliter droplets mixed within the cartridge
• Custom image-analysis algorithm that observes state changes to determine positive samples and quantify endotoxin levels
• Dried and stored reagents that are hydrated upon demand, simplifying operation and extending shelf life
• Time-based detection capable of differentiating between 0.1, 1, and 10.0 EU/mL endotoxin concentrations
• Current analytical sensitivity of 0.25 EU/mL, with a project target of 0.03 EU/mL
• Designed for continuous, autonomous operation, potentially enabling real-time sampling from dialysis lines or other clinical streams

Technology readiness level

The technology has completed proof-of-concept validation, demonstrating reproducible detection of positive endotoxin samples at 0.25 EU/mL sensitivity. The research team has outlined five development aims for a one-year collaborative project: translating the assay into an inexpensive cartridge format, integrating dried reagents with shelf-life validation, improving analytical sensitivity to 0.03 EU/mL, conducting blinded head-to-head testing against the gold-standard LAL method to establish clinical sensitivity and specificity, and developing autonomous continuous-sensing capabilities for point-of-use deployment. The system is currently at an early-to-mid stage of development, with active work focused on miniaturization, sensitivity enhancement, and clinical validation.