Near-infrared fluorimetric determination of nucleic acids by shifting the ion-association equilibrium between tetracarboxy aluminum phthalocyanine and tetra-N-hexadecylpyridiniumyl porphyrin.
A new method was developed for determination of micro amounts of nucleic acids based on near-infrared (near-IR) fluorescence recovery, employing a two-reagent system which is composed of an anionic tetracarboxy aluminum phthalocyanine (AlC(4)Pc) and a cationic tetra-N-hexadecylpyridiniumyl porphyrin (TC(16)PyP). The fluorescence of the AlC(4)Pc, with the maximum emission wavelength at 701nm, could be quenched by TC(16)PyP at its proper concentration, but recovered by adding nucleic acids. Under optimal conditions, the recovered fluorescence is proportional to the concentration of nucleic acids. The calibration graphs are linear over the range of 1-200ngmL(-1) for fish sperm DNA (FS DNA) and 2-400ngmL(-1) for calf thymus DNA (CT DNA). The corresponding detection limits are 0.59ngmL(-1) for FS DNA and 0.82ngmL(-1) for CT DNA, respectively. Four synthetic and three real nucleic acid samples were determined with satisfactory results.
Zhuo
Shu-Juan
SJ
College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China.
Zheng
Hong
H
Chen
Jin-Long
JL
Li
Dong-Hui
DH
Wu
Yu-Qin
YQ
Zhu
Chang-Qing
CQ