title: Ultra-sensitive electrical immunoassay biosensors using nanotextured zinc oxide thin films on printed circuit board platforms.
abstract: This study demonstrates the development of nanotextured zinc oxide (ZnO) thin films sputter deposited on printed circuit boards (PCB) to enhance the capability in detecting low concentrations of the protein troponin-T. The presence of this particular biomarker in the bloodstream is a direct indicator of current and/or future risk of various forms of cardiovascular diseases. Electrical transduction through impedance spectroscopy was used to detect troponin-T functionalized immunoassays on nanotextured ZnO surfaces. Calibration of the immunoassay was performed by measuring the impedance changes resulting from the binding of increasing concentrations of troponin-T to the immobilized antibodies on the ZnO surface in (i) phosphate buffered saline (PBS) and (ii) human serum. The limit of detection achieved using this platform was 10 fg/mL and 100 fg/mL in PBS and human serum, respectively. Enhanced detection of troponin-T was found to correlate to the oxygen vacancies in the ZnO thin film. PCB was chosen as the substrate for ease of integration with microelectronic device manufacturing.
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Jacobs
authors.affiliation: Department of Materials Science and Engineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080, USA.
authors.forename: Sriram
authors.initials: S
authors.lastname: Muthukumar
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080, USA.
authors.forename: Anjan
authors.initials: A
authors.lastname: Panneer Selvam
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Engel Craven
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, EC 39, Richardson, TX 75080, USA. Electronic address: Shalini.Prasad@utdallas.edu.
authors.forename: Shalini
authors.initials: S
authors.lastname: Prasad
mesh_terms: D000906:Antibodies / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D008567:Membranes, Artificial; D008832:Microchemistry / Q000295:instrumentation; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties; D020107:Troponin T / Q000097:blood* / Q000276:immunology; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000906:Antibodies; D008567:Membranes, Artificial; D020107:Troponin T; D015034:Zinc Oxide
keywords: Electrical immunoassay; Label-free detection; Troponin-T detection; Zinc oxide biosensors