The characteristics of absorption, fluorescence, room temperature phosphorescence(RTP) spectra of meso tetrakis(4 N trimethylaminobenzyl)porphin(TAPP) and Palladium porphyrin(Pd TAPP) probe in the presence and absence of ct DNA has been studied. Pd TAPP shows a very weak RTP emission in aqueous solution and strong RTP emission in the presence of DNA. Maximum RTP was observed at pH=7, with maximum excitation and emission wavelengths at 414 nm and 684 nm, respectively. RTP decay follows a first order exponential equation, RTP lifetime (τ) of probe is (0.72±0.03) ms. The detection limit of ct DNA may reach 8.8×10 -7 mol/L. The relative standard deviation(RSD) is less than ±6.6% in the linear range.
