The synthesis of sustainable and promising biomaterials for biomedical applications has recently gained increasing importance. In this study, a hybrid hydrogel was synthesized from empty palm date bunches through the blending of natural (carboxymethyl cellulose) and synthetic polymers (polyvinyl alcohol, polyvinylpyrrolidone) using both traditional and microwave-assisted methods. The aim was to investigate the ability of the hydrogel to immobilize and control the release of bovine serum albumin (BSA), a model protein widely used in pharmaceutical biotechnology. The effect of key parameters such as pH, temperature and hydrogel dosage on protein immobilization was investigated. Optimal results were observed at a pH of 7.4, a temperature of 37 °C and a dosage of 2 g/L—such conditions are very close to the human physiological environment. Kinetic and isotherm models indicated that the immobilization process adhered to pseudo-second-order kinetics and was well-fitted to the Langmuir isotherm. This implied a monolayer adsorption mechanism on a comparatively homogeneous surface. The release studies demonstrated a time-dependent and diffusion-controlled trend, with BSA attaining equilibrium release at 150 min. Overall, the results underline the potential of the microwave-synthesized plant-based hydrogel as a promising material for controlled drug delivery and other biomedical applications due to its efficiency and sustainability.