The spectroscopic fingerprint of TNT between 395 and 495Â nm determined from transmission near field optical microscopy measurements

Deposits of trinitrotoluene (TNT) prepared with an aerosol jet are examined with surface reflection Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and near field optical microscopy. Significant structure is observed in the vibrational spectrum of TNT particles in the N-O stretching region around 1530 cm−1 and in the spectroscopic finger print determined from transmission near field scanning optical microscopy (NSOM) measurements between 395 and 405 nm as well as in the absorption spectra of bulk quantities of TNT. About 7 fg of TNT are detected in the transmission NSOM measurements.