A Portable Impedance Biosensing System based on a Laptop with LabVIEW for Rapid Detection of Avian Influenza Virus

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for data communication. A gold interdigitated microelectrode was coated with specific aptamers to bind H5N1 virus and used in a microflow cell to obtain changes in impedance with desired accuracy and sensitivity. A sampling delivery unit consisted of a pump and three valves and was controlled by the virtual instrument to provide automated operation with adjustable flow rate. Results of the impedance measured with this biosensing system were compared with a commercial IM 6 impedance analyzer, and the error was less than 5%. The experiments on AIV H5N1 virus showed a linear relationship between the impedance change and the concentration of AIV H5N1 in a detection range from 2 to 16HAU.The specificity for detection of AIV H5N1 was confirmed with three non-target AIV subtypes, H1N1, H5N2, and H5N3.The biosensing system is portable and automated and has great potential to serve as a diagnostic and epidemiological tool for in-field rapid detection of AIV and other pathogens.