A novel method for measuring photosynthesis using delayed fluorescence of chloroplast.

Photosynthesis is the most important chemical reaction in the world. The measurement of plant photosynthesis rate plays an important role in agriculture. Light-induced delayed fluorescence (DF) in plants is an intrinsic label of the efficiency of charge separation at P680 in photosystem II (PS II). In this paper, we have developed a biosensor that can accurately measure the plant photosynthesis ability by means of DF. Compared with common methods for measuring the photosynthesis rate based on consumption of CO2, the proposed technique can quantify the plant photosynthesis ability with less influence of the environment. The biosensor is an all-weather measuring instrument, it has its own illumination power and utilizes intrinsic DF as the measurement marker. The current investigation has revealed that, there is a good correspondence between the results measured by the biosensor and that by commercially available portable photosynthesis system under controlled conditions. We thus conclude that DF is an excellent marker for evaluating plant photosynthesis ability under its biological status with less interferences of the environment.