Assessment of WO3 electrode modified with intact chloroplasts as a novel biohybrid platform for photocurrent improvement

• Published in: Bioelectrochemistry (Amsterdam, Netherlands) Netherlands), 2022-10, Vol.147, p.108177-108177, Article 108177
• Main Authors: Silva, Caio César Gonçalves, Torquato, Lilian Danielle de Moura, de Araújo, Bárbara Camila, Mantilla, Hernan Dario Rojas, Zanoni, Maria Valnice Boldrin, Garrido, Saulo Santesso
• Format: Article
• Language: English
• Subjects: Biohybrid platform; Chloroplasts; Electrical measurement; Electrodes; Herbicides; Immobilization; Intact chloroplasts; Irradiation; Mediated electron transfer; Photobiocurrent enhancement; Photobioelectrocatalysis; Photoelectric effect; Photoelectric emission; Photosynthesis; Quantum efficiency; Radiation; Simazine; Substrates
• ISSN: 1567-5394; 1878-562X
• DOI: 10.1016/j.bioelechem.2022.108177

[Display omitted] •Intact chloroplasts from spinach used to produce enhanced photocurrent at a nanoporous WO3 electrode.•Easy preparation of a Chloroplast/PDA@WO3 biohybrid platform useful for photobioelectrochemical cell design.•Chloroplast/PDA@WO3 arrays irradiated by an LED system doubled the photocurrent when compared to the bare electrode. The present work describes an easy way to prepare a Chloroplast/PDA@WO3 biohybrid platform based on the deposition of chloroplasts on WO3 substrate previously modified with polydopamine (PDA) film as anchoring agent. The use of PDA as an immobilization matrix for chloroplasts, and also as an electron mediator under LED irradiation, resulted in enhanced photocurrents. The use of the chloroplasts amplified the photocurrent, when compared to the bare substrate (WO3). The best electrode performance was obtained using high intensity LED irradiation at 395 nm, for the electrode exposed for 10 min to 150 μg mL−1 of intact chloroplasts. Amperometric curves obtained by on/off cycles using an applied potential of +0.50 V, in PBS electrolyte (pH 7.0), showed that the presence of 0.2 × 10−3 mol L−1 of simazine caused an approximately 50% decrease of the photobiocurrent. Preliminary studies indicated that the synthesized platform based on intact chloroplasts is a good strategy for studying the behavior of photosynthetic entities, using an LED light-responsive WO3 semiconductor substrate. This work contributes to the understanding of photobiocatalysts that emerge as a new class of materials with sophisticated and intricate structures. These are promising materials with remarkably improved quantum efficiency with potential applications in photobioelectrocatalysis.