title: Sensitive detection of influenza viruses with Europium nanoparticles on an epoxy silica sol-gel functionalized polycarbonate-polydimethylsiloxane hybrid microchip.
abstract: In an effort to develop new tools for diagnosing influenza in resource-limited settings, we fabricated a polycarbonate (PC)-polydimethylsiloxane (PDMS) hybrid microchip using a simple epoxy silica sol-gel coating/bonding method and employed it in sensitive detection of influenza virus with Europium nanoparticles (EuNPs). The incorporation of sol-gel material in device fabrication provided functionalized channel surfaces ready for covalent immobilization of primary antibodies and a strong bonding between PDMS substrates and PC supports without increasing background fluorescence. In microchip EuNP immunoassay (µENIA) of inactivated influenza viruses, replacing native PDMS microchips with hybrid microchips allowed the achievement of a 6-fold increase in signal-to-background ratio, a 12-fold and a 6-fold decreases in limit-of-detection (LOD) in influenza A and B tests respectively. Using influenza A samples with known titers, the LOD of influenza µENIA on hybrid microchips was determined to be ~10(4) TCID50 titer/mL and 10(3)-10(4) EID50 titer/mL. A comparison test indicated that the sensitivity of influenza µENIA enhanced using the hybrid microchips even surpassed that of a commercial laboratory influenza ELISA test. In addition to the sensitivity improvement, assay variation was clearly reduced when hybrid microchips instead of native PDMS microchips were used in the µENIA tests. Finally, infectious reference viruses and nasopharyngeal swab patient specimens were successfully tested using μENIA on hybrid microchip platforms, demonstrating the potential of this unique microchip nanoparticle assay in clinical diagnosis of influenza. Meanwhile, the tests showed the necessity of using nucleic acid confirmatory tests to clarify ambiguous test results obtained from prototype or developed point-of-care testing devices for influenza diagnosis.
authors.affiliation: Laboratory of Molecular Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States. Electronic address: Jikun.Liu@fda.hhs.gov.
authors.forename: Jikun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratory of Molecular Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States.
authors.forename: Jiangqin
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Petrochenko
authors.affiliation: Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993, United States.
authors.forename: Jiwen
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Laboratory of Molecular Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, United States. Electronic address: Indira.Hewlett@fda.hhs.gov.
authors.forename: Indira
authors.initials: I
authors.lastname: Hewlett
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004853:Epoxy Resins / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005063:Europium / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis / Q000276:immunology / Q000821:virology*; D056656:Lab-On-A-Chip Devices; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D011076:Polycarboxylate Cement / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D004853:Epoxy Resins; D011076:Polycarboxylate Cement; C005506:polycarbonate; D005063:Europium; C013830:baysilon; D012822:Silicon Dioxide
keywords: Europium nanoparticle; Immunoassay; Influenza; Lab-on-a-chip; Sol-gel coating; Surface functionalization