Table 1. Atomic concentrations of MWNT, amino-functionalised MWNT and amino-functionalised MWNT bound enzyme from XPS experimental data.

Nanomaterial	Atomic concentration of oxygen (%)	Atomic concentration of nitrogen (%)
MWNT	1.0	–
Amino-functionalised MWNT	13	5
Amino-functionalised MWNT bound enzyme	20	14

All experiments in this study were carried out in triplicate with standard deviation below 5%.