title: Multi-scale silica structures for improved HIV-1 Capsid (p24) antigen detection.
abstract: Silica (SiO2) micro- and nanostructures fabricated with pre-stressed thermoplastic shrink wrap film have been shown to yield far-field fluorescence signal enhancements over their planar or wrinkled counterparts. The SiO2 structures have previously been used for improved detection of fluorescently labelled proteins and DNA. In this work, we probe the mechanism responsible for the dramatic increases in fluorescence signal intensity. Optical characterization studies attribute the fluorescence signal enhancements to increased surface density and light scattering from the rough SiO2 structures. Using this information, we come up with a theoretical approximation for the enhancement factor based off the scattering effects alone. We show that increased deposition thickness of SiO2 yields improved fluorescence signal enhancements, with an optimal SiO2 thin layer achieved at 20 nm. Finally, we show that the SiO2 substrates serve as a suitable platform for disease diagnostics, and show improved limits of detection (LOD) for the human immunodeficiency virus type 1 (HIV-1) p24 antigen.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA 92697, USA. mkhine@uci.edu.
authors.forename: Sophia
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Per Niklas
authors.initials: PN
authors.lastname: Hedde
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA 92697, USA. mkhine@uci.edu and Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Vasan
authors.initials: V
authors.lastname: Venugopalan
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA 92697, USA. mkhine@uci.edu and Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Khine
mesh_terms: D002213:Capsid / Q000737:chemistry*; D016655:HIV Core Protein p24 / Q000032:analysis*; D015497:HIV-1; D057230:Limit of Detection; D049329:Nanostructures; D012822:Silicon Dioxide
chemical_list: D016655:HIV Core Protein p24; C514799:p24 protein, Human Immunodeficiency Virus Type 1; D012822:Silicon Dioxide