Manganese Removal from the Seo-Gok Reservoir Water Using DNA Aptamers

Manganese (Mn) is widely used in many industries but is also biologically harmful when abundant in the environment. While there are several commercially available methods for manganese removal from water, efficient and cost-effective solutions for addressing manganese contamination in diverse environmental matrices remain limited. In this study, we developed a new method for removing Mn from contaminated lakes using an aptamer. The Seo-Gok Reservoir was selected as the study area due to its significant levels of Mn contamination. We first screened aptamers that bind to Mn through systematic evolution of ligands by exponential enrichment (SELEX). Among 6 aptamers (from FA-M1 to FA-M6), the FA-M1 aptamer exhibited the highest binding affinity to Mn with the lowest Kd value of 4.56 × 10−9 M. Potential Mn-binding sites in aptamers were predicted by analyzing the secondary structures. To confirm the binding of Mn to the proposed region, we evaluated the sequence homology of the screened aptamers. Aptamer specificity was evaluated against diverse metals. We demonstrated that FA-M1 could remove more than 95% of Mn from an aqueous sample; 99.9% of this Mn could then be recovered. FA-M1 removed more than 90% of Mn from a sample of the Mn-contaminated Seo-Gok Reservoir, indicating that aptamers can be utilized to remove Mn ions from the environment.