Small molecule lateral flow device for sensitive detection of acrylamide
A novel protein-engineered lateral flow detection platform for small molecules such as acrylamide. Uses computationally designed protein dimers that bind target molecules at their interface, enabling sensitive field testing without antibodies. Suitable for food safety and environmental monitoring applications.
Overview
This technology addresses a critical gap in point-of-need diagnostics: the detection of small molecules such as acrylamide, a probable carcinogen found in cooked and processed foods. Conventional lateral flow tests rely on antibodies, which are difficult or impossible to generate against small molecules. This platform replaces antibody-based detection with an engineered protein system that dimerizes only when the target small molecule is present, enabling rapid, sensitive, and field-deployable testing.
The core value proposition is the ability to detect small molecules using a simple, low-cost lateral flow format without requiring antibody development. This opens new diagnostic and monitoring opportunities for food manufacturers, environmental testing services, and public health agencies seeking affordable screening tools.
Technical specifications
The system uses two engineered proteins that form a functional dimer upon binding the target molecule at their interface. Key technical features include:
- Engineered protein dimer design: Two small protein subunits (56 amino acids each) that remain monomeric in the absence of the target molecule but strongly dimerize when the target binds at the interface
- Computational protein design: A protein design algorithm performs computational mutagenesis and energy assessment to identify amino acid mutations that enable target binding and induce dimerization
- Directed evolution: Semi-biased randomization of interfacial residue positions followed by screening using a bacterial surface display technology
- Gold nanoparticle bioconjugation: Proteins are conjugated to gold nanoparticles via a C-terminal cysteine-containing linker, producing a blue-shifted UV spectrum suitable for lateral flow readout
- Robust expression: Protein subunits express well in E. coli, enabling scalable production
- Reengineered for acrylamide: The system was originally validated using metal binding (zinc, cobalt, nickel) and is now being reengineered to specifically detect acrylamide
Technology readiness level
The core detection concept has been validated using metal ions (zinc, cobalt, nickel) as proof-of-principle targets. The system has demonstrated successful bioconjugation to gold nanoparticles with the expected optical response. Current work focuses on reengineering the protein interface to recognize acrylamide through computational design and directed evolution. The technology is at an early-to-mid stage of development, with the foundational protein engineering and nanoparticle conjugation validated and ongoing efforts directed toward acrylamide-specific binding and full lateral flow device integration.
About San Diego State University
San Diego State University is a comprehensive public research university in San Diego serving a large, diverse student body with an applied, partnership-focused research culture. The growing Mission Valley innovation district enables co-location of corporate partners with faculty labs, while the university’s binational position links companies to the San Diego–Tijuana corridor and regional talent. An affiliated research foundation streamlines contracting and compliance for industry-sponsored work, and campus incubator programs support entrepreneurship. Research is supported by competitive federal funding from the National Science Foundation, National Institutes of Health, and the U.S. Department of Defense. A dedicated technology transfer office provides IP management, licensing, and startup support.
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