A functionalized mesoporous silica sensor for the determination of p-nitrophenol or 2,4-dinitrophenol based on fluorescence quenching

Mesoporous silica was synthesized and functionalized by sequential modifications. Silica reacted first with 3-aminopropyltriethoxysilane and then with 1 -pyrenecarboxaldehye to obtain aminopyrenefunctionalized mesoporous silica. Functionalized silica has been used as sensing material for nitrophenols determination based on fluorescence quenching. Response sensitivity of the sensor to nitrophenols is in the sequence 2,4-dinitrophenol approximate to p-nitrophenol > picric acid > o-nitrophenol > m-nitrophenol. The linear range for p-nitrophenol detection lies in 3.60 x 10(-6) similar to 8.99 x 10(-5) mol center dot L-1 with a detection limit of 7.78 x 10(-7) mol center dot L-1 (S/N = 3). For 2,4-dinitrophenol, the linear range is 3.62 x 10(-6) similar to 7.24 x 10(-5) mol center dot L-1, and the detection limit is 3.52 x 10(-7) mol center dot L-1.