In-situ photochemical spectrofluorimetric detection of 9,10-anthraquinone-labeled bovine serum albumin

Bovine serum albumin (BSA) labeled with 9,10-anthraquinone (AQ) shows a greatly enhanced photochemical fluorometric activity compared with that of free AQ. The spectral characteristics of the photoreduction product of conjugated AQ was investigated and large blue shifts in the excitation and emission bands compared with those of free AQ were observed. The enhancement in the photochemical reactivity can be employed for sensitive detection of labeled BSA by a simple in-situ photochemical kinetic fluorimetric method. The kinetic behavior of the photochemical reaction and the effects of some experimental conditions were investigated. The calibration graph was linear over the range 0-1.8 x 10(-7) M BSA. The detection limit was 1.2 x 10(-10) M BSA and the relative standard deviation was 2.24% for the 1.42 x 10(-8) M BSA (n = 7).