Interdigitated array microelectrode based impedance immunosensor for detection of avian influenza virus H5N1

Area of Science:

• Biosensors and Nanotechnology
• Virology and Immunology
• Public Health and Veterinary Medicine

Background:

• Avian influenza (AI) outbreaks pose significant threats to animal and human health, necessitating rapid diagnostic tools.
• Existing detection methods may lack the speed, sensitivity, or specificity required for timely intervention during AI outbreaks.

Purpose of the Study:

• To develop and validate a novel impedance immunosensor for the sensitive, specific, and rapid detection of avian influenza virus H5N1.
• To investigate the sensor's performance, including detection limits, linearity, and interference from other viruses.

Main Methods:

• Development of an interdigitated array (IDA) microelectrode-based impedance immunosensor.
• Immobilization of polyclonal antibodies against H5N1 Hemagglutinin (HA) using Protein A on a gold electrode surface.
• Utilized red blood cells (RBCs) as biolabels for signal amplification and atomic force microscopy (AFM) for confirmation.

Main Results:

• The immunosensor detected AI H5N1 virus at titers >10^3 EID50/ml within 2 hours.
• A linear detection range for H5N1 virus was established between 10^3 and 10^7 EID50/ml.
• Equivalent circuit analysis confirmed impedance changes due to specific binding events and amplification, with no significant interference from other viruses.

Conclusions:

• The developed impedance immunosensor provides a sensitive, specific, and rapid platform for detecting pathogenic AI H5N1.
• This technology holds potential for improved surveillance and early warning systems for avian influenza.
• The use of RBCs as biolabels effectively amplifies the detection signal.