Flow injection chemiluminescence sensor using core-shell molecularly imprinted polymers as recognition element for determination of dapsone

This paper reports the preparation of dapsone (DDS) imprinted polymer layer-coated silica submicron particles (SiO2) combined with chemiluminescence (CL) toward analysis of tracing DDS in practical samples. To induce the selective occurrence of surface polymerization, the amino groups were first grafted at the surface of SiO2 by the (3-aminopropyl)triethoxysilane (APTES). The molecularly imprinted polymers (MIP) were coated at the surface of modified SiO2 by the graft copolymerization. After the removal of templates, recognition sites of DDS were exposed in the polymer layers. The DDS-imprinted products were characterized by FT-IR, SEM, TEM, dynamic adsorption, and static adsorption tests. The proximity between the thickness of MIP layer and the spatial size of DDS indicated that the imprinted sites almost situated at the surface of MIP, leading to rapid adsorption saturation within 90 min. The apparent maximum binding amount of MIP toward DDS was evaluated as 14.98 mg·g−1, which was much higher than that of non-molecularly imprinted polymers. The CL sensor provided a wide linear range for DDS within 1.0 × 10−6 to 1.0 × 10−4 mol·L−1 with a detection limit of 5.27 × 10-7 mol·L−1 and the relative standard deviation of 1.8 % (n = 11) by determinations of 5.0 × 10−6 mol·L−1 DDS. This method was applied to determine DDS in urine samples and satisfactory results were obtained.