Surface ligand stability is crucial for biosensing, corrosion protection, and biomedical devices. Electrochemical Impedance Spectroscopy (EIS) enables real-time, in situ, monitoring of stability, but traditional redox-mediated EIS introduces baseline drift and alters surface properties. This work investigates non-redox-mediated EIS as an alternative approach to characterize ligand stability without these interferences. Different EIS analysis methods were evaluated: Equivalent Circuit Modeling (ECM), Characteristic Feature Analysis (CFA), and Distribution of Relaxation Times (DRT). Surfaces functionalized with 6-mercapto-1-hexanol, 3-mercapto-1-propanol, and carboxylphenol were studied as representative platforms with varying stability profiles. Initial results indicated ECM limitations due to high fitting errors and interpretive ambiguities. Further investigations into CFA and DRT will determine their effectiveness in providing frequency-resolved insights into ligand stability. This study highlights the potential advantages of non-redox-mediated EIS and identifies analytical strategies for evaluating surface stability.
