Development of methylene blue imprinted silica for detecting arsenic ions in aqueous solution

Arsenic pollution is caused by industrial activities of human beings such as the mineral product manufacturing industry and metal industries. Arsenic pollution can cause nervous system and cardiovascular diseases in humans and destroy various water-based ecosystems. So far, different chemical analysis equipment is being utilized to carry out measurements of arsenic. However, conventional chemical analysis techniques are restricted by their needs for large or expensive equipment, which prevents convenient and rapid measurement. Here, we show that convenient measurements of arsenic can be conducted through the utilization of silica that has been modified with methylene blue molecules (MB-Silica). Several studies have reported that the interaction of methylene blue (MB) with arsenic in aqueous solution leads to color variations caused by oxidation-reduction reactions. Taking these alterations in colors into consideration, we have developed a convenient approach for arsenic detection by synthesizing MB-Silica. Furthermore, by varying the MB concentration during synthesis, arsenic ions can be detected with various concentration gradients, validating the feasibility of aqueous arsenic detection. Since the possibility of detecting arsenic using MB-silica, developed in this study, was successfully confirmed, it is anticipated that the MB-silica will be extensively used to detect arsenic in the field.