Synthesis and crystal structure of a novel copper(ii) complex of curcumin-type and its application in in vitro and in vivo imaging

Abstract

A novel multibranch Cu(II) complex CuL₂·C₄H₈O₂ (L = 1,7-bis(4-ethyloxy-3-methyloxy-phenyl)-1,6-heptadiene-3,5-dione) was obtained and its crystal structure was determined. The linear photophysical properties, two-photon absorption (2PA), and photostability behavior of the obtained complex were investigated. The experimental results show that the complex exhibits a larger 2PA cross-section in the NIR region, higher quantum yield and photostability and lower cytotoxicity. The in vitro study utilized the human breast cancer MCF-7 cell line that was imaged by two-photon fluorescence microscopy. The tumor targeting capability of the complex on tumor-bearing nude mice in vivo demonstrated its high targeting capability to test cancerous cells. These results suggest that the Cu(II) complex is a promising probe for in vivo imaging.