Surface-enhanced Raman spectra of some anti-tubercle bacillus drugs

Surface-enhance Raman (SER) spectra of pyrazinamide (PZA), isoniazid (INAZ) , and isonicotiamide (INCT) in silver sols have been studied over a range o f solution concentration and pH. A linear calibration curve has been obtain ed for each of the Sample molecules, and the lower limits of detection are estimated to be 5 ng for PZA and INAZ, and 10 ng for INCA. The variation of SER intensity with the sample solution pH is explained in terms of the cha rge of the sample species and the stability of the sols. The normal Raman a nd infrared spectra for the pure drug samples have also been collected, fro m which some vibration assignments for the molecules are given. The absorpt ion behaviors of the molecules on the silver particle surfaces are also sug gested. (C) 2000 Elsevier Science B.V. All rights reserved.