Chelation-Induced Zwitterion-like Antifouling Behavior on Anionic Poly(3,4-ethylenedioxythiophene) Surfaces

Antifouling properties are crucial for enhancing the longevity and functionality of biomedical implants, drug delivery systems, and biosensors. Zwitterionic polymers are renowned for their exceptional surface hydration and charge neutrality, which effectively resist biomolecular adsorption and protein attachment. We propose an innovative approach to develop zwitterion-like antifouling surfaces by chelating divalent cations with anionic poly(3,4-ethylenedioxythiophene) (PEDOT) films, specifically PEDOT-PO₄ and PEDOT-COOH. The chelation behavior of these films was systematically evaluated using Na⁺, Mg²⁺, and Ca²⁺ ions. Divalent ions, particularly Ca²⁺ and Mg²⁺, exhibit a strong affinity for the anionic groups, leading to significant antifouling properties. These modified surfaces effectively repelled both negatively charged bovine serum albumin (BSA) and positively charged lysozyme (LYZ) proteins across various pH environments. This study offers valuable insights into the antifouling characteristics of charged surfaces, enhancing our understanding of how ion-mediated surface modifications influence protein adsorption and interactions.