Simple adsorption-based immobilization of L-asparaginase on boron-doped diamond film
九月23, 2025
Simple adsorption-based immobilization of L-asparaginase on boron-doped diamond film
L-asparaginase (ASNase) is a clinically and industrially important enzyme but suffers from instability in free form. Immobilization on boron-doped diamond (BDD) was explored as a strategy to enhance stability and reusability. BDD films were synthesized via hot-filament chemical vapor deposition (HFCVD) on Si substrates, followed by surface functionalization through NH₃ or O₂ plasma to create amine- or oxygen-terminated surfaces.
At optimized conditions (pH 8, 37 °C, 0.06 mg/mL ASNase, 1 h immobilization), adsorption immobilization was achieved with yields up to 68.3% for amine-terminated BDD, compared to only ~17% for untreated as-grown surfaces. Oxygen-terminated BDD also improved yield (37.1%). Amine-functionalized BDD retained 54% of initial activity after three reuse cycles, outperforming oxygen-terminated and untreated surfaces.
Comprehensive film characterization confirmed successful BDD synthesis and doping (SEM, XRD, Raman, AFM, contact angle). Plasma functionalization increased surface hydrophilicity (contact angle ~36° vs. ~90° for untreated) and promoted enzyme adsorption. Morphological changes after immobilization observed by AFM further verified protein attachment.
Significance
Enzyme immobilization efficiency: Highest on amine-terminated BDD (68%).
Operational stability: Amine-terminated BDD enabled higher activity retention across cycles.
Material advantage: BDD combines chemical robustness, biocompatibility, semiconductivity, and resistance to fouling, outperforming other carbon supports.
Applications: Provides a reusable and stable ASNase platform for biosensing and potential biopharmaceutical or food-processing applications (e.g., leukemia therapy, acrylamide reduction).
Key Takeaway
This study demonstrates that amine-terminated BDD surfaces are highly effective supports for ASNase immobilization via simple adsorption, yielding both high immobilization efficiency and enhanced reusability. These findings highlight BDD’s promise as a next-generation platform for enzyme-based biosensors and catalytic applications.
#BDD # Boron doped diamond #Diamond film#Diasemi
