Thylakoid direct photobioelectrocatalysis: utilizing stroma thylakoids to improve bio-solar cell performance

Abstract

Thylakoid membranes from spinach were separated into grana and stroma thylakoid fractions which were characterized by several methods (pigment content, protein gel electrophoresis, photosystem activities, and electron microscopy analysis) to confirm that the intact thylakoids were differentiated into the two domains. The results of photoelectrochemical experiments showed that stroma thylakoid electrodes generate photocurrents more than four times larger than grana thylakoids (51 ± 4 nA cm⁻² compared to 11 ± 1 nA cm⁻²). A similar trend was seen in a bio-solar cell configuration with stroma thylakoids giving almost twice the current (19 ± 3 μA cm⁻²) as grana thylakoids (11 ± 2 μA cm⁻²) with no change in open circuit voltage.