SBA-15 functionalized with naphthalene derivative for selective optical sensing of Cr 2 O 72- in water

Abstract

A novel organic-inorganic hybrid optical sensor (NUS) was designed and prepared in two steps: the grafting of 3-(isocyanatopropyl)trimethoxysilane onto the surface of SBA-15, and then the attachment of naphthalene-1-amine. The obtained materials were characterized using low-angle XRD, N 2 adsorption-desorption, TGA, FT-IR, and TEM techniques. A fluorescence study revealed that the NUS was a highly selective optical sensor for the detection of Cr 2 O 72- among various anions, including F - , I - , Cl - , Br - , CO 32- , HCO 3- , NO 3- , H 2 PO 4- , CH 3 COO - , and NO 2 - with a good linearity between the fluorescence intensity and the concentration of Cr 2 O 72- as well as a detection limit of 1.2 × 10 -7 M in a 100% aqueous medium. Moreover, the applicability of real samples of the sensor is also discussed.