Enhanced photostability of chlorophyll-ausing gold nanoparticles as an efficient photoprotector

• Published in: Journal of materials chemistry Vol. 22; no. 48; pp. 25316 - 25324
• Main Authors: Barazzouk, Said, Bekale, Laurent, Hotchandani, Surat
• Format: Journal Article
• Language: English
• Published: 01.11.2012
• Subjects: Binding; Carotene; Gold; Illumination; Nanoparticles; Photodegradation; Plants (organisms); Quinones
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c2jm33681b

Improving the photostability of chlorophylls is one of the main challenges to facilitate their industrial and biotechnological use. In this regard, we have employed gold nanoparticles (AuNPs) to photoprotect chlorophyll-a(Chla). The results show that the photodegradation of Chlais slowed down in the presence of AuNPs, and an increase of as much as an order of magnitude in half-life time of Chlain the presence of AuNPs has been observed. It is further seen that under in vitroconditions, AuNPs are much better photoprotective agents of Chlathan beta -carotene or quinones, which are known to be very effective under natural living conditions (plants). The protecting ability of Chlaby AuNPs is the result of their efficient binding with Chlaat its nitrogen sites even in the dark, thus inhibiting the reaction of reactive oxygen species with Chla, known to cause its degradation during illumination. The same property of AuNPs, i.e., to bind with Chlain the dark, renders them to be a better photoprotectant than carotene or quinones since these agents offer protection to Chladuring its illumination.