This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum.

This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum.

Philosophiae Doctor - PhD / This study firstly reports the development and characterization of PVP-AgNPs, PANSA and PVPAgNPs/ PANSA nanocomposite on gold. AFM and TEM analyses revealed highly electroactive nanocomposites whose morphogy and properties were essential for the immobilization of CYP2E1. Secondly, the development and characterization of Au/PVPAgNPs/ PANSA/CYP2E1, Au/PVP-AgNPs/PANSA/SA-CYP2E1 and Au/PVPAgNPs/ PANSA/EG-CYP2E1 nanobiosensors are reported. AFM studies displayed globular morphologies with large roughness for the enzyme modified electrodes as opposed to those electrodes without enzymes. Finally, the biotransformation of standard solutions of TB drugs (isoniazid, ethambutol, pyrazinamide and rifampicin) in pH 7.4, 0.1 M phosphate buffer solution is reported. The biotransformations of the TB drugs were successfully studied using cyclic voltammetry (CV), square wave voltammetry (SWV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. Very good detection limits were obtained for the standard solutions of TB drugs and were found to be in the micromolar range. The detection limit values for the individual TB drugs were 0.55 μM (isoniazid), 0.7 μM (ethambutol), 0.054 μM (pyrazinamide) and 0.05 μM (rifampicin). The detection limit results showed that the nanobiosensors were more sensitive and suitable for the determination of the respective drugs in plasma and serum. / South Africa