Detection of Singlet Oxygen Formation inside Photoactive Biohybrid Composite Material

• Published in: Materials Vol. 11; no. 1; p. 28
• Main Authors: Hajdu, Kata, Ur Rehman, Ateeq, Vass, Imre, Nagy, László
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26-12-2017; MDPI
• Subjects: Biomedical materials; Composite materials; Converters; Energy conversion efficiency; Histidine; Multi wall carbon nanotubes; Nanotubes; Optoelectronics; Oxidation; Oxygen production; Photosynthesis; Proteins; Singlet oxygen; Sorption; multiwalled carbon nanotubes; singlet oxygen; photosynthetic reaction center; photoactive nanocomposites
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma11010028

Photosynthetic reaction center proteins (RCs) are the most efficient light energy converter systems in nature. The first steps of the primary charge separation in photosynthesis take place in these proteins. Due to their unique properties, combining RCs with nano-structures promising applications can be predicted in optoelectronic systems. In the present work RCs purified from
purple bacteria were immobilized on multiwalled carbon nanotubes (CNTs). Carboxyl-and amine-functionalised CNTs were used, so different binding procedures, physical sorption and chemical sorption as well, could be applied as immobilization techniques. Light-induced singlet oxygen production was measured in the prepared photoactive biocomposites in water-based suspension by histidine mediated chemical trapping. Carbon nanotubes were applied under different conditions in order to understand their role in the equilibration of singlet oxygen concentration in the suspension. CNTs acted as effective quenchers of ¹O₂ either by physical (resonance) energy transfer or by chemical (oxidation) reaction and their efficiency showed dependence on the diffusion distance of ¹O₂.