Preparation and optimization of ordered porous interference enhanced substrate based on ordered porous layer interference system

To overcome the problems of small pore size and limited reaction space of silica colloidal crystal (SCC) films, an ordered porous polystyrene (PS) -TiO 2 interference enhanced substrate with large pore size, high porosity, good interference efficiency and transparency was developed by introducing a TiO 2 interference enhanced layer with dip-coating method. The obtained substrate consists of three parts: the nanoporous structure layer, the PS substrate layer, and the TiO 2 layer between the two layers. The optical and mechanical properties of the obtained substrate was studied and optimized. The results showed that the optimal thickness of the PS substrate layer was 0.2 mm and that of TiO 2 interference enhanced layer was between 200 ∼ 400 nm. Combined with the ordered porous layer interference (OPLI) system, a continuous flow biosensor platform for real-time monitoring of the specific binding of Staphylococcus aureus protein A (SPA) and human serum immunoglobulin G (hIgG) was constructed to simulate an antibody screening test. The signal response of the system was about 3.8 times that of the system constructed with SCC substrate under the same conditions. The development of this new substrate provides the necessary support for the application expansion of the OPLI system, and had good application prospects in antibody screening, target protein binding performance evaluation and antibody drug development.