Online photolytic optical gating of caged fluorophores in capillary zone electrophoresis utilizing an ultraviolet light-emitting diode.
Photolytic optical gating (POG) facilitates rapid, on-line and highly sensitive analyses, though POG utilizes UV lasers for sample injection. We present a low-cost, more portable alternative, employing an ultraviolet light-emitting diode (UV-LED) array to inject caged fluorescent dyes via photolysis. Utilizing the UV-LED array, labeled amino acids were injected with nanomolar limits of detection (270 ± 30 nM and 250 ± 30 nM for arginine and citrulline, respectively). When normalized for the difference in light intensity, the UV-LED array provides comparable sensitivity to POG utilizing UV lasers. Additionally, the UV-LED array yielded sufficient beam quality and stability to facilitate coupling with a Hadamard transform, resulting in increased sensitivity. This work shows, for the first time, the use of an UV-LED for online POG with comparable sensitivity to conventional laser sources but at a lower cost.
Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA.
Elyssia S
ES
Gallagher
Troy J
TJ
Comi
Kevin L
KL
Braun
Craig A
CA
Aspinwall
D000465:Algorithms; D000596:Amino Acids / Q000737:chemistry; D055615:Electrical Equipment and Supplies; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D010782:Photolysis; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays
D000596:Amino Acids; D005456:Fluorescent Dyes