Red-shifted emission from 1,2-dioxetane-based chemiluminescent reactions.
Commercial chemiluminescent reagents emit across a broad portion of the electromagnetic spectrum (400-500 nm). A challenge to the use of chemiluminescence to monitor biological processes is the presence of interfering substances in the biological optical window. In the present study, longer wavelength emitting fluorophores (the organic dyes Alexa 568 and Alexa 647), and a semiconductor nanoparticle (QDOT800) were used to red-shift the emission from commercially available 1,2-dioxetane-based chemiluminescent substrate reactions. By adding non-conjugated fluorescent emitters into chemiluminescent reaction mixtures, an emission peak occurred at the predicted wavelength of the fluorescent emitter. The excitation and emission from QDOT800 was preserved in the presence of a 100 µm-thick glass barrier separating it from the chemiluminescent reaction components. The maximum tissue phantom penetration by QDOT800 emission was 8.5 mm; in comparison, the native chemiluminescent emission at 500 nm was unable to penetrate the thinnest tissue phantom of 2.5 mm. The described method for red-shifted emissions from chemiluminescent reactions does not require direct interaction between the chemiluminescent reaction and the fluorescent emitters. This suggests that the mechanism of chemiluminescent excitation of fluorophores and QDOT800 is not exclusive to chemiluminescence resonance energy transfer or sensitized chemiluminescence, but rather by broad energization from the native chemiluminescent emission.
Department of Pathology, University of Texas Southwestern Medical Center and Children's Medical Center, Dallas, TX, USA; Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Jason Y
JY
Park
Joshua
J
Gunpat
Li
L
Liu
Brooks
B
Edwards
Alana
A
Christie
Xian-Jin
XJ
Xie
Larry J
LJ
Kricka
Ralph P
RP
Mason
D004396:Coloring Agents / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006573:Heterocyclic Compounds, 1-Ring; D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry; D012666:Semiconductors; D013055:Spectrophotometry, Infrared
D004396:Coloring Agents; D006571:Heterocyclic Compounds; D006573:Heterocyclic Compounds, 1-Ring; C079142:1,2-dioxetane
CRET; chemiluminescence; chemiluminescence resonance energy transfer; near-infrared; quantum dot