Maryam Hatamimoslehabadi

Shining Light on the Dark Side of Imaging: Excited State Absorption Enhancement of a Bis-styryl BODIPY Photoacoustic Contrast Agent

A first approach toward understanding the targeted design of molecular photoacoustic contrast agents (MPACs) is presented. Optical and photoacoustic Z-scan spectroscopy was used to identify how nonlinear (excited-state) absorption contributes to enhancing the photoacoustic emission of the curcuminBF2 and bis-styryl (MeOPh)2BODIPY dyes relative to Cy3.

Photophysical and Photoacoustic Properties of π-Extended Curcumin Dyes. Effects of the Terminal Dimethylamino Electron-donor and the Bridging Aryl Ring

The synthesis, photophysical and photoacoustic characterization for a series of nine π‐extended quadrupolar curcumin dyes is presented. A systematic evaluation of the π‐bridging unit including the p‐phenyl, naphth‐4‐yl, thien‐2‐yl and hybrid 4‐naphthathien‐2‐yl groups is presented. Furthermore, evaluation of the strongly donating donor‐π‐acceptor‐π‐donor quadrupolar dimethylamino terminated derivatives is also included. Select dyes exhibit excited state absorption at increased laser fluence which translates to the production of a nonlinear enhanced photoacoustic response. In particular, the bis‐4‐dimethylaminonaphtha‐2‐thien‐5‐yl curcuminBF2 contrast agent DMA‐5 exhibits an excellent molar photoacoustics (PA) emission at both low (9.4 × 103 V M−1) and high (1.47 × 105 V M−1) laser fluence which is confirmed by its strong contrast by photoacoustic tomography (PAT). In summary, the strong absorbance and enhanced photoacoustic properties of naphthyl and thienyl curcuminoids here presented provides great promise for future photoacoustic imaging applications as demonstrated by preliminary PAT studies.

Linear and Nonlinear Absorption Enhanced Photoacoustic Response of BODIPY and Curcuminoid Photoacoustic-phores

We report the development of efficient photoacoustic-phores based on BODIPY and curcuminiod fluorophores. Enhancement of PA response is attributed to strong linear absorption and excited state at incident wavelength, and long lived excited states.

Blood Oxygen Saturation Measurements using Photoacoustic Z-scan Technique

Blood oxygen saturation (sO2) estimation is important in medicine. Nonlinear absorption coefficient (β) of various sO2 level blood samples were measured using photoacoustic Z-scan technique. Results depict linear dependency between β and sO2.

BODIPY derivatives as molecular photoacoustic contrast agents

Photoacoustic imaging (PAI) is emerging as a key in vivo imaging technique. Endogenous contrast agents alone are insufficient to obtain high contrast images necessitating a need for synthetic exogenous contrast agents. In recent years a great deal of research has been devoted to the development of nanoparticle based contrast agents with little effort on molecular systems. Here we report on the design and evaluation of BODIPY inspired molecular photoacoustic contrast agents (MPACs). Through chemical modification of the established BODIPY fluorophore, increasing its vibrational freedom and appending with non-emissive functionalities, it is demonstrated that the S0-S1 absorbed excitation energy is redirected towards a nonradiative excited-state decay pathway. Optical and photoacoustic characterization of the modified BODIPY MPACs demonstrates a stronger photoacoustic signal compared to the corresponding fluorescent BODIPY probes.