Fluorescence lifetime-based biosensing of zinc: Origin of the broad dynamic range

• DOI: 10.1007/bf00727528
• Publication Date: 2004-12-01T04:40:24Z
• Authors: Richard B. Thompson; Marcia W. Patchan
• Keywords: 01 natural sciences; 0104 chemical sciences

Fluorescence lifetime-based chemical sensors have recently been described for applications in medicine, environmental monitoring, and bioprocess control. These sensors transduce the level of the analyte as a change in the apparent fluorescence lifetime of an indicator phase. We have previously developed a wavelength-ratiometric fluorescence biosensor for zinc based on binding of zinc and dansylamide to apo-carbonic anhydrase which exhibited high sensitivity and selectivity. We demonstrate that the apo-carbonic anhydrase/dansylamide indicator system is very well suited for lifetime-based sensing, with a subnanomolar detection limit and greater than 1000-fold dynamic range. The theoretical basis for the wide dynamic range is discussed.