Interference Effect of Tubular Colloidal Crystal Films and Their Biosensing Applications.

Accurate in vitro lumen models are critical for simulating physiological microenvironments, as numerous biological processes are intrinsically linked to lumen structure. However, current models are difficult to simulate the curvature-dependent biomechanics and dynamic flow conditions of luminal systems, limiting their utility in complex biological matrices. In this study, tubular colloidal crystal films are prepared by combining biomimetic microstructures with photonic crystal technology and utilized its unique interference effect to achieve dynamic monitoring of biomolecular interactions. The interference effects are observed in highly ordered and structurally uniform tubular films prepared based on solvent evaporation-induced self-assembly. By adjusting the inner diameter of the glass tube and the concentration of the colloidal suspension and simultaneously measuring the optical thickness and refractive index response of the film to ethanol gradients, the curvature tunability, structural stability, and functional feasibility of the tubular films were evaluated. Furthermore, Staphylococcus aureus protein A (SPA)-functionalized tubular films combined with an ordered porous layer interferometry system enable in situ real-time monitoring of human immunoglobulin G binding and release from SPA-modified materials, validating the platform's feasibility. This strategy of integrating curvature bionic design with photonic crystal technology provides a dynamic biomimicry, real-time response, and visualization analysis platform for studying physiological microenvironments.