Abstract
This UCF invention is a portable, low-cost biosensing platform that enables rapid, quantitative detection of biomarkers using a smartphone. The technology is based on a structurally colored plasmonic surface that undergoes a visible color shift when target biomolecules bind to capture agents immobilized on the sensor. Unlike traditional antibody detection methods that rely on chemical labels, reagents, or specialized instrumentation, this system provides a direct, label free, and reagent free readout. The color change is captured with a smartphone camera and analyzed through a custom mobile application to quantify biomarker concentration. This approach supports fast, accessible diagnostics suitable for point of care, at home testing, and field deployable health monitoring.The technology employs a structurally colored plasmonic
sensor formed by a reflective metal layer, a dielectric spacer, and a randomly
self-assembled aluminum nanoparticle layer fabricated using scalable,
lithography-free methods. These elements create subwavelength cavities that
support hybrid plasmonic modes, producing vivid, angle-independent structural
colors.
Technical Details: The sensor consists of a multilayer plasmonic nanostructure fabricated using lithography-free, scalable techniques, including a reflective metal layer, a dielectric spacer, and a randomly self-assembled aluminum nanoparticle layer. Together, these elements form subwavelength cavities that support hybrid optical modes arising from the coupling of localized surface plasmon resonances and gap plasmon modes. This hybridization produces vivid, angle- and polarization-independent structural colors.
Biorecognition elements, such as antibodies, are immobilized on the sensor surface using standard silane-based functionalization and bioconjugation chemistry. When target analytes bind to the surface, they induce a local refractive index change, which shifts the plasmonic resonance and produces a measurable color change. Images of the sensor are acquired using a smartphone under ambient lighting conditions.
A dedicated mobile application processes the captured images by performing localized white-balance correction, extracting color values, converting them into perceptually uniform Lab* color space, and computing Euclidean distance relative to a baseline control. This color-space metric correlates with analyte concentration, enabling quantitative detection without laboratory equipment.
Benefit
Eliminates reliance on chemical labels, reagents, and multi-step assays.Removes the need for bulky optical instruments or trained personnel.Provides robust, quantitative readouts that are insensitive to viewing angle and lighting variations.Enables low cost, scalable, and portable diagnostics, expanding access to timely biomarker detection.Market Application
Point-of-care and at home diagnostics for infectious disease and immune response monitoring.Public health screening and bio-surveillance, including decentralized testing campaigns.Environmental and field based biosensing where laboratory infrastructure is unavailable.Telemedicine and digital health platforms integrating smartphone-based diagnostics.
Brochure
