Real-time imaging of photosynthetic oxygen evolution from spinach using LSI-based biosensor

Area of Science:

• Plant Physiology
• Photosynthesis Research
• Biophysical Chemistry

Background:

• Photosystem II utilizes a Mn4O5Ca cluster for light-driven water splitting and oxygen (O2) evolution.
• Understanding O2 evolution dynamics is crucial for plant biology and photosynthesis research.

Purpose of the Study:

• To develop and validate a novel electrochemical imaging system for real-time O2 evolution monitoring in plants.
• To investigate the dose-dependent effect of light intensity on O2 release from spinach leaves.
• To assess the impact of herbicides on photosynthesis-related O2 evolution.

Main Methods:

• Utilized a large-scale integration (LSI)-based amperometric sensor array (Bio-LSI) with 400 electrodes for 2D imaging.
• Applied varying intensities of white light (400-700 nm) to spinach leaves.
• Collected electrochemical images to quantify light-induced O2 evolution and its suppression by DCMU.

Main Results:

• Bio-LSI successfully generated 2D images of light-induced O2 evolution from spinach leaves.
• Observed a clear dose-dependent relationship between light intensity and O2 release.
• Demonstrated significant suppression of O2 evolution in the presence of the herbicide DCMU.

Conclusions:

• The Bio-LSI system is a promising tool for real-time electrochemical imaging of O2 evolution in plants.
• This study provides the first electrochemical imaging of light-induced O2 evolution using LSI-based amperometric sensors in plants.
• The findings highlight the potential for monitoring photosynthetic activity and herbicide effects in real-time.