N-Acetylcysteine (NAC) serves as an essential precursor of cysteine, thereby facilitating the production of glutathione (GSH), a vital antioxidant in numerous biological processes. Its role as an antioxidant encompasses various functions, such as scavenging harmful oxidants, replenishing GSH levels, and participating in antioxidant signaling pathways. NAC has a well-established history as a prescription drug, and due to its wide range of potential benefits, it is also utilized in various over-the-counter (OTC) applications. Water-based carbodiimide science was utilized to make NAC-functionalized Ch films instead of perilous organic solvents. Here, we detail the techniques taken to enhance the immobilization of NAC onto the outer layer of recently delivered Ch coatings in request to amplify NAC openness. Various surface characterization techniques, including ellipsometry, water contact angle measurements, and X-ray photoelectron spectroscopy (XPS), confirmed the successful immobilization of N-Acetylcysteine (NAC) at a concentration of 4 mg/mL. Additionally, a valuable quartzite dissipative microbalance (QCM-D) demonstrated that the NAC immobilization on the surface led to a reduction in protein adsorption to the Ch coating.