Synthesis of Near-infrared Cyanine Dye Library with Increased Photostability and its Application in Fluorescence and SERS Imaging

Abstract

With the emerging interest in optical in vivo imaging, there is an increasing demand of photostable near-infrared (NIR) dyes. Therefore, we applied a combinatorial approach to identify CyNA-414 as the most photostable among 80 photostable tricarbocyanine dyes (CyNA). Next, we modified CyNA-414 for bioconjugation (CyNE790) and proved its superiority considering its photophysical and photostability properties compared with standard ICG. The superior in vivo imaging was further confirmed by injecting CyNE790-anti-EGFR into mice. Moreover, we developed a novel NIR fluorescent deoxyglucose analogue (CyNE-2DG) and proved its superior cell permeability and cellular imaging over the NIR standard IRDye800CW-2DG. However, we studied another good application of cyanine dyes in Surface-enhanced Raman Scattering (SERS). We employed a combinatorial approach to identify CyNAMLA-381 as highly sensitive NIR SERS reporters among 80 dyes. Then, we demonstrated ultrasensitive tumor detection in vivo by applying the nanotags (AuNPs-CyNAMLA-381-anti-HER2). Moreover, we designed a multiplexing partner of Raman reporters to enable the multiplex recognition of two different cancer cells with antibody-conjugated nanotags. We also demonstrated the multiplexing capability of three NIR Raman reporters in vivo.