Recent advances in near-infrared-II organic J-aggregates for bio-applications

Abstract

Near-infrared-II (NIR-II) phototheranostic agents (PTAs), utilizing the unique advantages of NIR-II light (1000–1700 nm), have become essential tools in the field of phototheranostics. The assembly of organic chromophores or fluorophores into J-aggregates results in bathochromic shifts in spectra, representing a promising method that significantly facilitates the development of NIR-II PTAs. J-aggregates are intriguing supramolecular assemblies formed by the highly ordered, slip-stacked alignment of organic chromophores, exhibiting distinctive optical properties, such as narrow and bathochromically shifted absorption and emission bands, along with enhanced molar extinction coefficients (MEC) compared to their monomers. Driven by the ongoing pursuit of NIR-II PTAs, the development of NIR-II J-aggregates is currently gaining positive momentum. These J-aggregate-based NIR-II PTAs excel in applications such as vasculature and tumor imaging, surgical navigation, and phototherapy, highlighting their potential in enhancing medical diagnostics and therapeutics. This review focuses on recent advancements in NIR-II organic J-aggregates for bio-applications over the past five years. First, various strategies for the formation and stabilization of J-aggregates are briefly introduced. Next, the latest progress in diverse NIR-II J-aggregates for bio-applications is systematically summarized. Finally, potential challenges and prospects are thoroughly discussed to guide the further development of high-performing NIR-II J-aggregates for improved bio-applications.