Determination of nucleic acid by [tetra-(3-methoxy-4-hydroxyphenyl)]-Tb3+ porphyrin as the fluorescence spectral probe in bis(2-ethylhexyl)sulfosuccinate sodium salt micelle system

Abstract

A new system for the determination of nucleic acid by rare earth metallic porphyrin of [tetra-(3-methoxy-4-hydroxyphenyl)]-Tb3+ [T(3-MO-4HP)-Tb3+] porphyrin as fluorescence spectral probe has been developed in this paper. Nucleic acid can enhance the fluorescence intensity of the T(3-MO-4HP)-Tb3+ porphyrin in the presence of bis(2-ethylhexyl)sulfosuccinate sodium salt(AOT) micelle. In pH 8.00 Tris-HCl buffer solution, under optimum conditions, the enhanced fluorescence intensity is in proportion to the concentration of nucleic acids in the range of 0.05-3.00 microg mL(-1) for calf thymus DNA (ct DNA) and 0.03-4.80 microg mL(-1) for fish sperm DNA(fs DNA). Their detection limits are 0.03 and 0.01 microg mL(-1), respectively. In addition, the binding interaction mechanism between T(3-MO-4HP)-Tb(3+) porphyrin and ct DNA is also investigated by resonance scattering and fluorescence spectra. The maximum binding number is calculated by molar ratio method. The new system can be used for the determination of nucleic acid in pig liver, yielding satisfactory results.