Abstract
The anticancer drug topotecan was detected in human plasma and whole blood using two-photon excitation at 730 or 820 nm. These wavelengths are longer than the main absorption bands of hemoglobin. Two-photon excitation of topotecan was demonstrated by a quadratic dependence of the emission intensity on the incident power, compared to a linear dependence for one- photon excitation at 410 nm. The observed emission centered at 525 nm was shown to be topotecan from the similarity of the emission spectrum and decay times observed for one-photon and two-photon excitation. Topotecan was detected at concentrations as low as 0.05 and 1 μM in plasma and whole blood, respectively. Since skin blood and tissues are translucent at long wavelengths, these results suggest the possibility of homogeneous or noninvasive clinical sensing with two-photon excitation.
Original language | English |
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Pages (from-to) | 266-270 |
Number of pages | 5 |
Journal | Analytical Biochemistry |
Volume | 242 |
Issue number | 2 |
DOIs | |
State | Published - 15 Nov 1996 |