Enhanced Optics for Time-Resolved Singlet Oxygen Luminescence Detection

Abstract

Singlet oxygen luminescence dosimetry (SOLD) is a highly promising direct monitoring method for photodynamic therapy (PDT) in the treatment of cancer. Early SOLD systems have been hampered by inefficient excitation, poor optical collection and immature infrared single photon detection technology. We report carefully engineered improvements addressing all of these deficiencies. We use a supercontinuum source with a tunable filter to precisely target the peak absorption wavelength of the chosen photosensitizer; we have designed a compact and versatile optical package for precise alignment; we have successfully employed state-ofthe-art superconducting photon counting technologies. Through these improvements, we can achieve histogram acquisition from a photosensitizer in solution test sample. This setup opens the pathway to physiological SOLD studies for PDT dosimetry.

Singlet Oxygen Luminescence Image in Blood Vessels During Vascular‐Targeted Photodynamic Therapy

“…The photosensitized 1 O 2 can undergo nonradiative decay (including oxidize surrounding biological molecules) or radiative decay, and the emission of 1 O 2 occurs over a narrow spectral band centered at around 1270 nm (4,5). However, the direct detection of 1 O 2 luminescence is of great technical challenge since it has extremely low emission probability (10 À8 -10 À6 ) and short lifetime (ns~ls) in biological environments (6)(7)(8)(9)(10)(11)(12). During the past two decades, with the advances in NIR detector, two designs were developed for the direct imaging of 1 O 2 luminescence.…”

Investigation of Electronic Structures of Triplet States Using Step-Scan Time-Resolved Fourier-Transform Near-Infrared Spectroscopy

“…After integration of the absorption difference in the 8500–10500 cm –1 region versus time, the decay curve, shown in Figure d, was deconvoluted with an instrument response function (fwhm of 400 ns, limited by the preamplifier) to yield a decay time constant of 537 ns. This band position agrees with that observed by Larkin et al, and the decay mainly results from oxygen quenching; the decay time constant is close to the decay of the triplet RB reported by Tsimvrakidis et al This band is blue-shifted to 9660 and 9850 cm –1 in the less polar solvents acetonitrile (ACN) and THF, respectively, with decay time constants of 700 and 1190 ns, respectively. The experimental data are listed in Figure S3.…”