Quantification and biodegradability assessment of meso-2,3-dimercaptosuccinic acid adsorbed on iron oxide nanoparticles

Abstract

Many interesting applications of magnetic iron oxide nanoparticles (IONPs) have recently been developed based on their magnetic properties and promising catalytic activity. Depending on their intended use, such nanoparticles (NPs) are frequently functionalized with proteins, polymers, or other organic molecules such as meso-2,3-dimercaptosuccinic acid (DMSA) to improve their colloidal stability or biocompatibility.Although the coating strongly affects the colloidal properties and environmental behaviour of NPs, quantitative analysis of the coating is often neglected. To address this issue, we established an ion chromatographic method for the quantitative analysis of surface-bound sulfur-containing molecules such as DMSA. The method determines the amount of sulfate generated by complete oxidation of sulfur present in the molecule. Quantification of the DMSA content of DMSA-coated IONPs showed that reproducibly approximately 38% of the DMSA used in the synthesis was adsorbed on the IONPs. Tests for the biodegradability of free and NP-bound DMSA using a microbial community from a wastewater treatment plant showed that both free and NP-bound DMSA was degraded to negligible extent, suggesting long-term environmental stability of DMSA-coated IONPs.

Fe3O4 nanoparticles affect paddy soil microbial-driven carbon and nitrogen processes: roles of surface coating and soil types

“…Recently, meso-2,3-dimercaptosuccinic acid (DMSA, surface-bound sulfur-containing molecules) has been preferred as a coating material due to its good chelating capability with metals and its harmlessness to humans or other mammals. 20 Previous studies have studied the stability of DMSA-coated nFe 3 O 4 (nFe 3 O 4 @DMSA) and their impact on aquatic organisms, [20][21][22] but whether nFe 3 O 4 @DMSA would influence terrestrial organisms has not been explored yet.…”