Quantum Modelling of Stokes-Induced Stark Fields in Quercetin–ZnO Nanohybrids for Bias-Free Bioelectric Repair of Chronic Diabetic Foot Ulcers

Abstract CONTEXT Chronic diabetic foot ulcers (DFUs) are associated with the collapse of endogenous bioelectric field gradients and redox-compromised wound microenvironments, conditions under which externally applied electroceutical stimulation and reactive-oxygen-species (ROS)–dominated photodynamic therapies become ineffective or deleterious. This limitation motivates the search for intrinsic, bias-free mechanisms capable of regenerating localized bioelectric cues using benign external energy inputs. At photoactive organic–semiconductor interfaces, excited-state intramolecular proton transfer (ESIPT) offers a pathway by which molecular photophysics may be converted into interfacial electrostatic modulation, yet this transduction mechanism has not been formulated within a rigorous quantum–electrostatic framework. METHOD Here, we develop a first-principles quantum modelling framework establishing the Stokes-Induced Stark Effect (SISE) at quercetin–ZnO interfaces as a bias-free mechanism for interfacial electric-field generation. Visible-light excitation of chemisorbed quercetin induces ultrafast ESIPT-driven Stokes relaxation, accompanied by excited-state dipole reconfiguration (Δµ ≈ 5–15 D, τ ≈ 100 fs). This time-dependent dipole couples electrostatically to ZnO surface states, generating localized interfacial Stark fields of order 10⁵–10⁶ V·m⁻¹. Using a composite molecular–semiconductor Hamiltonian incorporating dielectric screening and surface-state quantization, we show that although instantaneous fields are strongly attenuated in physiological media (Debye length \(\:{\lambda\:}_{D}\:\approx\:\:0.8\) nm), spatiotemporal integration via dipole-density gradients and continuous low-intensity illumination yields effective quasi-static bioelectric cues at the interface (E_eff ≈ 50–500 V·m⁻¹). The model explicitly avoids assumptions of static field penetration and instead delineates a defined operational window (coverage factor η ≈ 0.3–0.7; illumination < 10 mW·cm⁻²) in which electrostatic guidance dominates over ROS-driven photochemistry. The framework provides quantitative design constraints and experimentally testable predictions, establishing SISE as a physically plausible molecular-photophysics-driven route for bias-free bioelectric modulation, with chronic wound repair serving as a representative application context.