nanocages; lateral flow assay; nanoparticles; biosensing; analytical chemistry; nanochemistry


Lateral flow assay (LFA) has been demonstrated as a promising point-of-care biosensor due to its facile use and low cost. These immunoassays utilize nanoparticles as a colorimetric label to conjugate with the antibody and create a colored signal for antigen detection. Typically, gold or silver nanoparticles are used for this procedure. However, the sensitivity of these materials is not high enough to detect certain biomarkers such as the prostate specific antigen (PSA) which is a biomarker for prostate cancer. Replacing the nanoparticles with dual metal nanocages with a hollow interior has potential to improve the state of the flow test. Dual metal nanocages generated through galvanic replacement have been studied for their unique plasmonic and catalytic properties. In this study, silver-palladium nanocages were synthesized using a galvanic replacement reaction to create dual-metal, hollow nanocages. The particles were characterized for their bimetallic nature with x-ray photoelectron spectroscopy, their hollow structure with transmission electron microscopy, and their plasmonic properties with UV-Vis spectroscopy. Particles of three different sizes were created to investigate a size effect on antigen detection. The nanocages were used to as the label for immunoassay which produced a black, colored signal, and the medium and large AgPd NPs improved the tests’ naked eye limit of detection against standard 40 nm gold nanoparticles by tenfold and twenty-fivefold respectively. The medium and large AgPd NPs also had a considerable increase in calibration sensitivity when converting qualitative measurement into quantitative signal. With this work, it is our hope to improve the sensitivity of lateral flow assay and sustain the procedure as a reliable form of point-of-care testing.

Thesis Completion Year


Thesis Completion Semester


Thesis Chair

Xia, Xiaohu


College of Sciences



Thesis Discipline




Access Status

Campus Access

Length of Campus Access

5 years

Campus Location

Orlando (Main) Campus

Available for download on Wednesday, April 30, 2025



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