Detection of Tomato Ringspot Virus Based on Microfluidic Impedance Sensor

Area of Science:

• Biosensing
• Electrochemistry
• Plant Pathology

Background:

• Plant viruses like Tomato Ringspot Virus (ToRSV) cause significant agricultural losses.
• Accurate and rapid detection methods are crucial for managing ToRSV outbreaks.
• Existing detection methods can be time-consuming or require specialized equipment.

Purpose of the Study:

• To develop and validate a novel microfluidic impedance sensor for rapid and sensitive detection of ToRSV.
• To investigate the electrochemical impedance spectroscopy (EIS) mechanism underlying ToRSV detection.
• To establish a quantitative relationship between ToRSV concentration and sensor response.

Main Methods:

• Fabrication of a microfluidic sensor with gold interdigitated array microelectrodes.
• Immobilization of ToRSV antibodies on the electrode surface.
• Detection of ToRSV using electrochemical impedance spectroscopy (EIS).
• Analysis of impedance changes using an equivalent circuit model.

Main Results:

• The sensor demonstrated a linear quantitative relationship between ToRSV concentration (0.001–10 μg/mL) and impedance (R² = 0.98) at 10.7 Hz.
• Equivalent circuit analysis indicated that ToRSV increases solution resistance, electron transfer resistance, and double-layer capacitance.
• A low detection limit of 0.0032 μg/mL was achieved.

Conclusions:

• The developed microfluidic impedance sensor provides a rapid, sensitive, and precise method for ToRSV detection.
• The sensor's design and mechanism are suitable for detecting other plant viruses.
• This technology offers a promising tool for plant disease diagnostics and management.