A three-component supramolecular nanocomposite as a heavy-atom-free photosensitizer

Abstract

The preparation of a supramolecular nanocomposite containing BODIPY, tryptophan and gold nanoparticles capable of photosensitized generation of singlet oxygen is reported.

Fine‐Tuning Plasmon‐Molecule Interactions in Gold‐BODIPY Nanocomposites: The Role of Chemical Structure and Noncovalent Interactions

“…In NC1 , the position of H c is similar to that in Trp which indicates that tryptophan moieties are displaced by B1 thereby implying strong interaction of B1 with gold. We had reported significant changes in the 19 F NMR spectrum of NC1 as compared to B1 which substantiates strong interaction of B1 with gold [35] . Further, it is proposed that hydrogen bonds are formed between the aromatic −NH of the tryptophan and a fluorine atom of the −BF 2 unit of B1 .…”

“…It is noteworthy that the singlet oxygen quantum yield of NC1 and NC3 were reasonably high (0.46 and 0.42, respectively) and were comparable to that of methylene blue (Figure S20). It was also observed that Au NP was capable of generating singlet oxygen under similar conditions but the singlet oxygen quantum yield was significantly lower (φ ▵ =0.027) [35] …”

“…BODIPY molecules B1-B5 used in the present study were synthesized as per literature procedures [36][37][38][39] and were characterized by NMR and mass spectrometry ( Figures S1-S5). Nanocomposites NC1-NC5 were prepared as reported earlier [35] wherein a BODIPY molecule (B1-B5) in acetone was added to a stirred aqueous solution of L-tryptophan (Trp) and HAuCl 4 . The precipitated nanocomposites (NC1-NC5) were collected, purified by washing with water and characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS) ( Figures S6-S7).…”

“…Moreover, systematic studies correlating the effect of chemical structure and functional groups on plasmon‐molecule interactions are lacking. Recently, we reported a three‐component nanocomposite consisting of tryptophan, BODIPY and gold nanoparticles [35] . It was observed that tryptophan and BODIPY were non‐covalently attached onto the surface of gold nanoparticles and led to major changes in their photophysical properties.…”

“…Recently, we reported a three-component nanocomposite consisting of tryptophan, BODIPY and gold nanoparticles. [35] It was observed that tryptophan and BODIPY were non-covalently attached onto the surface of gold nanoparticles and led to major changes in their photophysical properties. Owing to the excellent singlet oxygen generation efficiency of the nanocomposite, it exhibited photocytotoxicity against cancer cells.…”