Low-cost paper-based biosensor for ultrasensitive endotoxin detection
A low-cost, rapid, ultrasensitive biosensor for endotoxin detection using single-walled carbon nanotube chemiresistors on paper substrate modified with endotoxin-binding peptides. Integrates with a smartphone platform for point-of-use testing at under $5 per test, offering 100-1000x higher sensitivity than home medical tests.
Overview
This technology is a low-cost, rapid, and ultrasensitive biosensor designed for detecting endotoxins (lipopolysaccharides) in solution. Built on a paper substrate using single-walled carbon nanotube (SWCNT) chemiresistor arrays, the biosensor is modified with endotoxin-binding peptides—polymyxin B (PMB) or a custom peptide (KC13)—that target the conserved lipid A epitope of endotoxins. A companion smartphone platform enables data collection, processing, and wireless reporting, making the system suitable for point-of-use and telemedicine applications in low-resource settings. At under $5 per test, the biosensor aims to deliver 100 to 1000-fold greater sensitivity than conventional home medical tests while maintaining simplicity and speed.
Technical specifications
Key features:
- SWCNT chemiresistor arrays fabricated on cellulose paper substrate using standard inkjet and wax printing for facile, low-cost production
- 3D microfluidic paper architecture enabling single small-volume sample analysis without pumps or valves
- Bioreceptor modification with PMB or KC13 peptides for high affinity and specificity to conserved lipid A endotoxin epitopes
- Smartphone platform (~$200) for data collection, processing, and wireless/cellular communication
- Multiplexing capability for detecting single or multiple analytes in one sample
- Validated performance for proteins and nucleic acids in buffer, blood, serum, saliva, and urine
Technology readiness level
The underlying SWCNT chemiresistor biosensor platform on paper substrate has been validated through three peer-reviewed publications and an international patent application, supported by NSF funding. Current NIJ and USDA-funded efforts are advancing the smartphone data platform. Remaining development steps include peptide immobilization optimization, analytical figure-of-merit characterization (sensitivity, specificity, accuracy, reproducibility, stability), endotoxin-specific validation in relevant solutions, and full integration with the smartphone platform for complete system testing.
About University of California, Riverside
UC Riverside is a comprehensive public research university within the UC system, recognized for translational work and talent development at scale. An on‑campus research and technology park, shared core facilities, and prototype spaces let companies co‑locate and validate new solutions alongside faculty. Partnerships with a medical enterprise and regional hospitals support clinical collaboration, while field sites and an extension network translate research to producers and communities across the region. Faculty secure competitive federal funding from NSF, NIH, DOE, and USDA, complemented by state and industry support. A dedicated technology transfer office streamlines IP, licensing, and startup formation, with incubator programming and flexible lab space for corporate collaborators.
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