A highly sensitive turn-on fluorescent probe with an aggregationLE-induced emission characteristic for quantitative detection of y-globulin

As a novel turn on fluorescent probe, 44(1Z,3Z)-1,4-bis(4-(methoxycarbonyl)pheny1)-4-(pyridin-4-yl)buta1,3-dien-1-y1)-1-methylpyridin-1-ium hexafluorophosphate (TABD-Py-PF6) with an aggregation-induced emission characteristic was synthesized for in-situ quantitation of y-globulins in the blood serum. It was shown that the TABD-Py-PF6 probe was highly specific for y-globulins and that other components in the blood serum, including serum albumins, fibrinogen, glucose, urea, and cholesterol, barely interfered with the molecular interactions between TABD-Py-PF6 and y-globulins. The high specificity of this probe enabled in-situ quantitative detection of y-globulins without isolation of y-globulins from the blood serum. The fluorescence intensity of TABD-Py-PF6 was linearly correlated with the concentration of y-globulins in the ranges of 7.89-300 pg/mL. The detection limit of y-globulins was determined to be 7.89 pg/mL. The fluorescence response time of TABD-Py-PF6 for detecting y-globulins was very short (below 5 s), allowing for real-time detection. The mechanism of the fluorescent turn-on behavior of the TABD-Py-PF6 probe was investigated and electrostatic interactions between TABD-Py-PF6 and y-globulins were identified.