Enhanced biophotoelectricity generation in cyanobacterial biophotovoltaics with intracellularly biosynthesized gold nanoparticles

[摘要] The demand for disposable power sources has propelled the development of cyanobacterial biophotovoltaics to effectively and self-sustainably generate biophotoelectricity. However, garnering electricity from cyanobacteria remains challenging because of the low efficiency of cyanobacterial electron harvesting and extracellular electron transfer. In this work, we propose biocompatible and highly stable gold nanoparticles intracellularly biosynthesized within the cyanobacteria as an effective light-absorber to increase photo-excited electrons and as an electrical conduit to improve the electron transfer through the cell membrane. The nanoparticles were synthesized internally and directly on the surface of Synechocystis sp. PCC 6803, through bioelectrochemical reduction of the metal ions. The cyanobacterial biophotovoltaics with the intracellular gold nanoparticles enhanced the maximum power density by as much as 33.6 times compared with the device without the nanoparticles. Even after the long cultivation (similar to 120 h), only a few dead cells (<8%) appeared in cyanobacteria with the in situ formed gold nanoparticle, indicating an insignificant adverse effect on cell viability and proving the feasibility of the modified cyanobacteria as an improved biophotovoltaic biocatalyst.

[发布日期] 2021-09-15

[关键词] Cyanobacterial biophotovoltaics;Biosynthesis;Gold nanoparticles;Biophotoelectricity;Light-harvesting;Electron transfer