Covalent immobilization—supports: which water-insoluble supports are commonly employed for covalent attachment of enzymes?

Introduction:
Choosing a support for covalent immobilization balances mechanical strength, chemical functionality, hydrophilicity, and biocompatibility. A wide range of organic and biopolymeric matrices have been used successfully to anchor enzymes via functional groups while maintaining activity and stability.

Given Data / Assumptions:

• Acrylamide-based polymers (e.g., polyacrylamide) can be functionalized for coupling.
• Polypeptide or proteinaceous matrices (e.g., collagen, gelatins) can provide reactive groups for mild coupling.
• Dextran (e.g., Sephadex derivatives) is a classic hydrophilic support easily activated (e.g., CNBr, epoxy).

Concept / Approach:
All listed materials have precedents as enzyme carriers after activation to introduce reactive handles (e.g., aldehyde, epoxy, carbodiimide-activated carboxyls). The choice depends on pH/solvent compatibility, pore structure, and targeted orientation to minimize active-site modification.

Step-by-Step Solution:
Step 1: Assess each material for water-insolubility and functionalizability.Step 2: Confirm literature usage for covalent immobilization.Step 3: Select the inclusive option covering all three support families.

Verification / Alternative check:
Handbooks on immobilized enzymes list activated dextrans, polyacrylamide gels, and protein-based matrices among standard carriers.

Why Other Options Are Wrong:

• Each single material alone is incomplete as an answer.
• Silica only: Silica is also common, but restricting to silica ignores the many polymer supports used widely.

Common Pitfalls:
Overlooking activation chemistry requirements; unactivated polymers may not couple efficiently without prior functionalization.

Final Answer:
all of these