応答性の高いフォトニックハイドロゲルを強化されたセンシング性能で構築するための普遍的なタンパク質固定化方法

Photonic crystal (PC) protein hydrogel sensors, a class of sensors integrating super-responsive protein hydrogels with the PC platform, attract intense interests owing to their numerous benefits and are especially ideal for use in resource-limited areas. However, they are constrained either in terms of the protein types as recognition molecules or the long-term stability of the pure protein hydrogel matrix. Here, we present an innovative acrylated protein method to develop two-dimensional (2D) PC hydrogel sensors. We chose a lysine-poor protein horseradish peroxidase (HRP) and a lysine-rich protein bovine serum albumin (BSA) to prepare 2D PC protein-polymer hybrid hydrogels and demonstrate the effectiveness of the method. We first immobilized HRP on an acrylamide (AAm/HRP) hydrogel to detect H₂O₂. The AAm/HRP hydrogel sensors possessed numerous advantages of superior selectivity, highly chemical stability for at least 14 weeks and exhibited a limit of detection (LoD) of 3.75 μM. The spiked lake water samples demonstrate recover rates ranging from 95.6 %-105.1 %. Furthermore, the AAm/HRP hydrogel sensors exhibited distinct structural colors at varying H₂O₂ concentrations, enabling quantitative detection via hue-dependent colorimetric analysis. More broadly, this method can also be used to develop other sensors for a wide variety of targets by simply replacing the proteins. BSA was also immobilized onto acrylamide hydrogels (AAm/BSA). The 2D PC AAm/BSA hydrogels were used to detect CaCl₂ with a LoD of 0.79 μM, reflecting the universality of our method. They also displayed outstanding stability exceeding 30 days. We believe that this universal approach enables future development of sensors with diverse applications.