4. Immobilization and Surface Chemistry

This chapter delves into the critical process of immobilizing proteins onto solid supports, a technique essential for enhancing surface density, minimizing non-specific adsorption, and improving detection performance. It explores various methods, including physical adsorption, entrapment, encapsulation, cross-linking, layer-by-layer (LbL) assembly, covalent binding, and bioaffinity, each with its unique advantages and challenges. Physical adsorption, while simple and rapid, often results in random enzyme orientations that can compromise activity. Entrapment and encapsulation offer protective benefits but may hinder mass transport. Covalent binding, on the other hand, provides stable and predictable immobilization, crucial for applications requiring high stability and reusability. The chapter also highlights the use of bioaffinity techniques, such as avidin-biotin interactions, which offer high specificity and reproducibility. Through detailed explanations and specific examples, this chapter provides a comprehensive guide to understanding and implementing protein immobilization techniques, making it an invaluable resource for professionals in biotechnology and related fields.