Graphene, Nanotubes, and Nanozymes: Smart Surface Engineering for High-Performance Biosensing

The integration of nanotechnology in biosensor development has unlocked new possibilities for highly sensitive and selective molecular detection. Nanomaterials exhibit exceptional electrical, catalytic, and structural properties that can be tailored to optimize biosensor performance. This presentation examines how engineered nanostructures and smart surface modifications enhance biosensor performance. Traditional enzyme-based biosensors were compared with integrated nanomaterial designs, optimizing enzyme immobilization and detection method parameters for the best stability and selectivity. For nanomaterial-based sensors, functionalization with graphene (G), carbon nanotubes (CNs), and NiCo₂O₄ improved charge transfer and catalysis, while chemically and biologically synthesized gold nanoparticles (AuNPs) were evaluated for enzyme-mimetic (nanozyme) and antioxidant properties.

Nanomaterial-functionalized biosensors demonstrated significant improvements in sensitivity and detection limits. A glucose oxidase-based biosensor utilizing a layer-by-layer self-assembly approach with G-CN composites achieved a low operational potential of -0.2 V vs. Ag/AgCl and a detection limit of 41 µM. Thyroxine detection was enhanced by incorporating NiCo₂O₄ on graphene oxide platforms, reducing the detection limit from 23 nM to 6.1 pM. Furthermore, biosensors leveraging the peroxidase-like activity of AuNPs enabled efficient oxidative stress detection via H₂O₂ quenching. Notably, biologically synthesized gold nanoparticles (Bio-AuNPs) preserved the intrinsic antioxidant properties of plant extracts, offering a sustainable and biocompatible alternative for biosensing applications.

The integration of nanostructured materials and smart surface engineering has significantly advanced biosensor technology, demonstrating superior analytical performance and real-sample applicability. These findings highlight the potential of nanomaterial-based biosensors for next-generation point-of-care diagnostics, paving the way for highly efficient, biocompatible, and sustainable sensing platforms.

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