Stable and Multifunctional Dye-Modified Black Phosphorus Nanosheets for Near-Infrared Imaging-Guided Photothermal Therapy

Abstract

Nanomedicines intergrating both therapy and diagnosis functions provide a promising strategy for anticancer treatment. As novel two-dimensional materials, black phosphorus nanosheets (BPs) possess unique properties for biomedical applications, pratically for photothermal therapy (PTT) of cancer, but their lack of air and water stability may hinder their application. Herein, a covalent functionalization strategy based on Nile Blue (NB) dye via diazonium chemistry is established to modify BPs, not only enhancing the stability of BPs but also rendering BPs via nearinfrared (NIR) fluorescence, forming a novel multifunctional nanomedicine with both PTT and NIR imaging capabilities. In vitro tests demonstrate that the dye-modified BPs (named NB@BPs) have good biocompatibility and exhibit strong PTT and NIR imaging efficiency. In vivo experiments show that the NB@BPs can mark the tumor site with red fluorescence and lead to efficient tumor ablation under NIR irradiation. These results reveal a potential BP-based nanomedicine with multiple functionalities that bode well for anticancer applications.

Chemistry of Layered Pnictogens: Phosphorus, Arsenic, Antimony, and Bismuth

“…Thediazonium radical chemistry was also reported for the functionalization of black phosphorus nanoparticles with Nile blue dye derivative. [19] Thec ovalent functionalization significantly changes the optical properties of BP nanoparticles,showing promising application potential in photothermal therapy.D iazonium chemistry was also reported as as tarting functionalization for further, more complex derivatization of black phosphorus.T he covalent functionalization was performed using 4-bromobenzenendiazonium tetrafluoroborate and introduced bromine was used for on-surface polymerization [20] and 4-nitrobenzenendiazonium tetrafluoroborate was used for stabilization of black phosphorus quantum dots, [21] which were used as an alkali pH sensor.…”

Two‐Dimensional Materials for Antimicrobial Applications: Graphene Materials and Beyond

“…Furthermore, most developed 2D materials suffer from insufficient long-term colloidal or chemical stability under ambient conditions, which significantly affects their antimicrobiale fficacy and clinicalt ranslation.O nce the 2D materials irreversibly agglomerate or become oxidized, the characteristic 2D structure becomes damaged, which leads to the loss of fascinating features derived from such au nique structure. For example, severals trategies have been developed to enhance the stability of BP nanosheets; [242][243][244] however,w hether their biodegradability and other outstanding properties are still retained should be carefully reevaluated. Because the lack of stabilityof2Dm aterials in aqueous solutions may restrict their applications under physiological conditions, the development of better capping agents for enhanced stabilitya nd the exploration of propers torage conditions for 2D materials are urgently required.…”

2D Elemental Nanomaterials Beyond Graphene

“…The diazonium chemistry of phosphorene is extended to covalently attach fluorescent dye Nile Blue 690 (NB‐690) to BP sheets . NB‐690 is first converted to corresponding diazonium salt and then reacted with BP nanosheets.…”