title: Real-time monitoring of macromolecular biosensing probe self-assembly and on-chip ELISA using impedimetric microsensors.
abstract: This paper presents a comprehensive study of the self-assembly dynamics and the biosensing efficacy of Tobacco mosaic virus-like particle (TMV VLP) sensing probes using an impedimetric microsensor platform. TMV VLPs are high surface area macromolecules with nanorod structures constructed from helical arrangements of thousands of identical coat proteins. Genetically modified TMV VLPs express both surface attachment-promoting cysteine residues and FLAG-tag antibody binding peptides on their coat protein outer surfaces, making them selective biosensing probes with self-assembly capability on sensors. The VLP self-assembly dynamics were studied by the continuous monitoring of impedance changes at 100Hz using interdigitated impedimetric microsensors. Electrical impedance spectroscopy revealed VLP saturation on impedance sensor surface with the coverage of 68% in self-assembly process. The VLP-functionalized impedance sensors responded to 12ng/ml to 1.2μg/ml of target anti-FLAG IgG antibodies in the subsequent enzyme-linked immunosorbent assays (ELISA), and yielded 18-35% total impedance increases, respectively. The detection limit of the target antibody is 9.1ng/ml using the VLP-based impedimetric microsensor. These results highlight the significant potential of genetically modified VLPs as selective nanostructured probes for autonomous sensor functionalization and enhanced biosensing.
authors.affiliation: Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
authors.forename: Faheng
authors.initials: F
authors.lastname: Zang
authors.affiliation: Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Gerasopoulos
authors.affiliation: Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
authors.forename: Xiao Zhu
authors.initials: XZ
authors.lastname: Fan
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA; Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Brown
authors.affiliation: Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA; Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD, 20742, USA.
authors.forename: James N
authors.initials: JN
authors.lastname: Culver
authors.affiliation: Department of Electrical and Computer Engineering, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA. Electronic address: ghodssi@umd.edu.
authors.forename: Reza
authors.initials: R
authors.lastname: Ghodssi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D036022:Capsid Proteins / Q000737:chemistry*; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D017097:Electric Impedance; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation*; D004867:Equipment Design; D007074:Immunoglobulin G / Q000032:analysis*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D014027:Tobacco Mosaic Virus / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; D007074:Immunoglobulin G
keywords: Bioreceptor; Impedance sensor; Macromolecule; Microfabrication; Virus-like particle