Electrical impedance spectroscopy of plant cells in aqueous buffer media over a wide frequency range of 4 Hz to 20 GHz.

Electrical impedance spectroscopy was performed on suspensions of plant cells in aqueous buffer media over a wide frequency range of 4 Hz to 20 GHz. Custom probes were designed, manufactured, and used for these investigations. Experiments were performed with a custom-made parallel plate probe and impedance analysers in the low-frequency range (4 Hz to 5 MHz), with a custom-made coaxial airline probe and a vector network analyser in the mid-frequency range (100 kHz to 3 GHz), and with a commercial open-ended probe and a vector network analyser in the high-frequency range (200 MHz to 20 GHz).

Electrical Impedance Spectroscopy of plant cells in aqueous biological buffer solutions and their modelling using a unified electrical equivalent circuit over a wide frequency range: 4Hz to 20 GHz.

A simple, ultra-wide frequency range, equivalent circuit for plant cell suspensions is presented. The model incorporates both the interfacial interactions of the suspension with the electrode, dominant at low frequencies, and the molecule and cell polarization mechanisms dominant at higher frequencies. Such model is useful for plant cell characterization allowing a single set of parameters over >9 orders of magnitude, whilst allows electronic simulations over the whole frequency range using a single model, simplifying the design of electronic systems of integrated plant cell sensors.

Integrated electrochemical Chip-on-Plant functional sensor for monitoring gene expression under stress.

The ability to interact with plants, both to sense and to actuate, would open new opportunities for precision agriculture. These interactions can be achieved by using the plant as part of the sensing system. The present work demonstrates real-time monitoring of β-glucuronidase (GUS) expression in transgenic tobacco plants using its activity as a biomarker for functional sensing.