Biofunctionalized carbon nanotubes platform for biomedical applications

• Electrophoretically deposited biofunctionlized MWCNT.
• Covalently attached Urs–GLDH on MWCNT provides more stable film.
• MWCNT provides a sensitive platform for detection of urea concentration.
• Enzymes modified MWCNT based electrode shows excellent affinity towards urea.

We have fabricated the chemically functionalized multi-walled carbon nanotubes (MWCNT) electrophoretically deposited onto indium tin oxide for urea detection. Urease and glutamate dehydrogenase are attached to MWCNT/ITO electrode surface covalently using ethyl-dimethylaminopropyl-carbodiimide and N-hydroxysuccinimide coupling chemistry. Excellent electrochemical properties of MWCNT and covalent functionalization of dual enzyme improve biosensor stability and sensitivity. The electrochemical response studies of the proposed biosensor exhibits wide detection range (0.83–24.9 mM), low detection limit (1.3 mM) and higher sensitivity of 4.67 μA mM−1 cm−2. The low magnitude (0.274 mM) of the apparent Michaelis–Menten constant (Km) value indicates high enzymatic affinity of Urs–GLDH enzymes on MWCNT/ITO electrode surface.