Luminescence changes upon Si-nanoparticle derivatization. A synthetic route to Al-tetracarboxyphthalocyanine funtionalized silicon nanoparticles.

DELLARCIPRETE MARÍA LAURA; CAREGNATO, PAULA; ROMERO, JUÁN JOSÉ; DI CELIO, LELIA; GONZALEZ, MÓNICA C.

Mendoza

Congreso; 21st I-APS Conference; 2011

Inter American Photochemical Society

Introduction: The unique optical properties of silicon nanoparticles (SiNP), their biocompatibility, and their capability to produce cytotoxic singlet oxygen (1O2) upon UV-visible and high energy X-rays irradiation, give them great potential as therapeutic agents in photodynamic and radiotheraphy of cancer. Phthalocyanines (Pc) are well-known 1O2 photosensitizers. Thus, the functionalization of SiNP with Pc is expected to present greater 1O2 generation capacity than isolated SiNP or Pc. Here we report the synthesis and the funtionalization route of SiNP with Al-tetracarboxyphthalocyanine (AlTCPc), known to interact with biomolecules [1]. The IR, the UV-vis, and the photoluminescence emission-excitation spectra of the synthesis- intermediates are presented. Experimental: The synthesis of silicon nanoparticles was performed using the reverse micelles approach [2]. Surface modification of the H-terminated Si NP with amine groups was achieved by silanization using aminoproyl-triethoxysilane (APTES) [3]. Activation of the AlTCPc is needed for coupling with the amine group of the SiNP and was carried out using N,N-dicyclohexylcarbodiimide (DCC) and N-hydroxysuccinimide ester (NHS) [4]. Incubation of NH2 terminated Si NP with AlTCPc at room temperature yields the Si NP- AlTCPc adduct. The luminescence spectrum and decay lifetime of the functionalized Si NP were obtained with a Jobin-Yvon Spex Fluorolog FL3-11 spectrophotometer. Results: Changes in the luminescence spectrum are observed for the different intermediate products of the synthetic route. The proposed synthetic route is shown below. [1] Q. H. Zhou, H. M. Zhang, L. Wu, Y. Q. Wang, Protein J., 2010, 29, 265?275. [2] M. Rosso-Vasic, L. De Cola, and H.Zuilhof, J. Phys. Chem. C, 2009, 113, 2235?2240. [3] K.M. Kamruzzaman Selima, Y. Haa, S. Kima, Y. Changb, T. Kimc, G. Leed, I. Kanga, Biomaterials, 2007, 28, 710?716. [4] I. V. Nesterova, V. T. Verdree, S. Pakhomov, K. L. Strickler, M. W. Allen, R. P. Hammer, and S. A. Soper, , Bioconjugate Chem., 2007, 18, 2159?2168.