Fluorescence sensing applications (e.g., on-line fiber-optic biosensors, DNA sequencing, DNA chips, protein detection, immunoassays) require functionalized fluorescent tags that can be covalently bound to sensing biomolecules. Near infrared (NIR) fluorescent dyes are desirable because non-specific background fluorescence is considerably reduced in the NIR spectral range and hence sensitivity can be significantly improved. Additionally, in the NIR, scattering is substantially reduced compared to the ultraviolet or visible spectral ranges due to the inverse fourth power dependence of scattering processes on wavelength. This is critical for fiber optic applications, where scattering within the fiber can severely limit the distances over which the optical signals may be transmitted. Moreover, excitation in the NIR can be accomplished with inexpensive laser diodes, which are compact and highly efficient. This results in low cost, compact, low power consumption instrumentation. Applications include biosensors, high-throughput drug screening, immunoassays, clinical diagnostics, and basic research.

Ciencia, in collaboration with scientists at the Center for Biomedical Imaging Technology, CBIT, at the University of Connecticut Health Center, has developed functionalized red and near-infrared fluorescent dyes, which possess excellent characteristics for biosensing and bioanalytical applications, including high quantum yield, high molar absorptivity, high environmental sensitivity, large Stokes shifts, large two-photon excitation cross-sections, lifetimes of about 1 ns, and absorption bands that overlap the output of common laser diodes.