Dar N, Weissman H, Ankri R. Adjustable Fluorescence Emission of J-Aggregated Tricarbocyanine in the Near-Infrared-II Region.
J Phys Chem B 2023;
127:7988-7995. [PMID:
37682586 PMCID:
PMC10518818 DOI:
10.1021/acs.jpcb.3c04554]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/23/2023] [Indexed: 09/09/2023]
Abstract
Near-infrared (NIR) J-aggregates attract increasing attention in many areas, especially in biomedical applications, as they combine the advantages of NIR spectroscopy with the unique J-aggregation properties of organic dyes. They enhance light absorption and have been used as effective biological imaging and therapeutic agents to achieve high-resolution imaging or effective phototherapy in vivo. In this work, we present novel J-aggregates composed of the well-known cyanine molecules. Cyanines are one of the few types of molecules whose absorption and emission can be shifted over a broad spectral range, from the ultraviolet (UV) to the NIR regime. They can easily transform into J-aggregates with narrow absorption and emission peaks, which is accompanied by a red shift in their spectra. In this work, we show, for the first time, that the tricarbocyanine dye (IR 820) has two sharp fluorescence emission bands in the NIR-II region with high photostability. These emission bands can be tuned to a desired wavelength in the range of 1150-1560 and 1675 nm, with a linear dependence on the excitation wavelength. Cryogenic transmission electron microscopy (cryo-TEM) images are presented, and combined with molecular modeling analysis, they confirm IR 820 π-stacked self-assembled fibrous structures.
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