Screen-Printed Carbon Electrodes Modified with Polymeric Nanoparticle-Carbon Nanotube Composites for Enzymatic Biosensing

An enzymatic H2O2 biosensor with a facile fabrication method was developed based on a screen-printed carbon electrode (SPCE) modified by the assembled distinct 0D/1D nanocomposite polymeric nanoparticles/carbon nanotubes (PAKB NPs-CNTs). First, copolymer (PAKB) was synthesized with glycoprotein-affinity monomers of 3-(acrylamido)phenylboronic acid, electroactive monomers of 9-(4-vinylbenzyl)-9H-carbazole and hydrophobic monomers of butyl methacrylate, and the polymeric nanoparticles (PAKB NPs) were prepared via the self-assembly of PAKB in a selective solution. The PAKB NPs-CNTs with 0D/1D nanostructures were then prepared by mixing PAKB NPs and CNTs with the generation of π–π interactions between the carbazole groups and CNTs. The PAKB NPs-CNTs with high glycoprotein affinity and electroactivity displayed large specific surface area and could immobilize enzymes, retain horseradish peroxidase (HRP) activity, and accelerate electron transfer. Finally, the biosensor was constructed through a successive dropping of the PAKB NPs-CNTs dispersion, HRP solution, and Nafion solution on the working electrode of SPCE. This biosensor presented a wide linear range from 0.02 to 6.48 mM and a detection limit of 2.7 μM (S/N = 3), as well as high sensitivity, excellent selectivity, short response time, and good stability. More importantly, an outstanding detection performance of biosensor was demonstrated when tested in real samples and complex systems.