Porphyrin-infiltrated SiO2 inverse opal photonic crystal as fluorescence sensor for selective detection of trace mercury ion

Abstract Sensing of heavy metal irons in aqueous medium is essential because the presence of heavy metals is very hazardous for environmental safety and human health. Here, a porphyrin-infiltrated inverse opal photonic crystal of silica (TPP-SiO2 IOPC) as the solid optical sensor has been prepared for the selective detection of mercury iron (Hg2+) in aqueous medium, while porphyrin is served as a fluorescence probe and the photonic crystal (PC) provides support as the backbone with special optical property. The intensity of fluorescence during the detection of Hg2+ on the TPP-SiO2 IOPC sensor is 38.9 times larger than that of control sample. The sensor has good linear response to the concentration of Hg2+ from 1.0 × 10−8 to 1.5 × 10−6 mol/L and the lower detection limit observed for Hg2+ concentration is 1.18 nM. Furthermore, the sensor exhibits excellent selection for Hg2+ rather than other metal ions. Therefore, the TPP-SiO2 IOPC sensor can be utilized for fast and simple monitoring of Hg2+.