Ultrabroadband Near-Infrared Transient Absorption Spectrometer with Simultaneous 900-2350 nm Detection.

In this work, we detail an ultrafast pump-probe transient absorption (TA) spectrometer capable of probing the near-infrared (NIR) spectral region from 900 to 2350 nm simultaneously. Two key advances were required to overcome previous spectral window limitations, which typically result from constrained supercontinuum ranges (e.g.

Synthesis and Characterization of Novel Thienothiadiazole-Based D-π-A-π-D Fluorophores as Potential NIR Imaging Agents.

As fluorescence bioimaging has increased in popularity, there have been numerous reports on designing organic fluorophores with desirable properties amenable to perform this task, specifically fluorophores with emission in the near-infrared II (NIR-II) region. One such strategy is to utilize the donor-π-acceptor-π-donor approach (D-π-A-π-D), as this allows for control of the photophysical properties of the resulting fluorophores through modulation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels. Herein, we illustrate the properties of thienothiadiazole (TTD) as an effective acceptor moiety in the design of NIR emissive fluorophores.

SWIR emissive RosIndolizine dyes with nanoencapsulation in water soluble dendrimers.

Shortwave infrared (SWIR) emission has great potential for deep-tissue biological imaging with high resolution. In this article, the synthesis and characterization of two new xanthene-based RosIndolizine dyes coded RosIndz and RosIndz is presented. The dyes are characterized femtosecond transient absorption spectroscopy as well as steady-state absorption and emission spectroscopies.

Self-Assembling PCL-PAMAM Linear Dendritic Block Copolymers (LDBCs) for Bioimaging and Phototherapeutic Applications.

This study represents a successful approach toward employing polycaprolactone-polyamidoamine (PCL-PAMAM) linear dendritic block copolymer (LDBC) nanoparticles as small-molecule carriers in NIR imaging and photothermal therapy. A feasible and robust synthetic strategy was used to synthesize a library of amphiphilic LDBCs with well-controlled hydrophobic-to-hydrophilic weight ratios. Systems with a hydrophobic weight ratio higher than 70% formed nanoparticles in aqueous media, which show hydrodynamic diameters of 51.

Donor-Acceptor-Donor NIR II Emissive Rhodindolizine Dye Synthesized by C-H Bond Functionalization.

A NIR II emissive dye was synthesized by the C-H bond functionalization of 1-methyl-2-phenylindolizine with 3,6-dibromoxanthene. The rhodindolizine () spirolactone product was nonfluorescent; however, upon opening of the lactone ring by the formation of the ethyl ester derivative, the fluorophore absorbs at 920 nm and emits at 1092 nm, which are both in the NIR II region. In addition, 4-cyanophenyl- () and 4-methoxyphenyl-substituted rhodindolizine () could also be prepared by the C-H activation reaction.

Surface and Interfacial Interactions in Dodecane/Brine Pickering Emulsions Stabilized by the Combination of Cellulose Nanocrystals and Emulsifiers.

Interfacial properties of cellulose nanocrystals (CNC) and surfactants were studied in high ionic strength () brines and correlated to the stability of dodecane/brine Pickering emulsions. Bis-(2-hydroxyethyl) cocoalkylamine (CAA), dodecyltrimethylammonium bromide (DTAB), and octyl-β-d-glucopyranoside (OGP) were adsorbed onto CNC in American Petroleum Institute (API) brine ( = 1.9 M) and synthetic seawater (SSW), with = 0.