Fluorescence detection of the anticancer drug topotecan in plasma and whole blood by two-photon excitation

Anal Biochem. 1996 Nov 15;242(2):266-70. doi: 10.1006/abio.1996.0463.

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 microM 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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antineoplastic Agents / blood*
  • Antineoplastic Agents / chemistry
  • Blood Chemical Analysis / methods*
  • Camptothecin / analogs & derivatives*
  • Camptothecin / blood
  • Camptothecin / chemistry
  • Chemistry Techniques, Analytical / methods
  • Humans
  • Infrared Rays
  • Lasers
  • Male
  • Photons
  • Plasma / chemistry
  • Skin / blood supply
  • Spectrometry, Fluorescence / methods*
  • Topotecan

Substances

  • Antineoplastic Agents
  • Topotecan
  • Camptothecin