Lipase immobilization on hollow-tubular graphitic carbon nitride (g-C₃N₄): Evaluation of catalytic activity and stability

In this study, hollow tube-shaped g-C₃N₄ was synthesized for biocatalytic immobilization of lipase enzyme and enzyme activity. SEM, EDS, FTIR, and XRD analyses were performed to characterize the synthesized hollow tube-shaped g-C₃N₄. The characterization results showed that the hollow tube-shaped g-C₃N₄ material, a graphitic carbon nitride, was successfully synthesized. Optimization of pH, temperature, reaction time, and material amount was performed for lipase enzyme immobilization and activity experiments. Under optimum conditions, at pH 6.00, 2.5 g/L of hollow tube-shaped g-C₃N₄, 12 h, and 40 °C, enzyme immobilization efficiency and activity values were obtained as 89.35% and 0.78 U/mL, respectively. The kinetic parameters of free and immobilized lipase were also determined using the Lineweaver–Burk model. These results clearly demonstrate that the hollow tube-shaped g-C₃N₄ material is a strong candidate for biocatalytic enzyme activity and enzyme immobilization applications.