Determination of Clenbuterol by Multiwalled Carbon Nanotube Potentiometric Sensors

Potentimetric sensors based on molecularly imprinted polymers are reported for the selective determination of clenbuterol. The work involved the modification of multiwalled carbon nanotubes, the modification of chitosan with diethylene triamine pentaacetic acid, the synthesis of the clenbuterol-imprinted polymer, and the preparation of potentiometric sensors using the clenbuterol-imprinted polymer. The effect of pH, response time, lifetime, selectivity, reusability, reproducibility, accuracy, and stability of the sensors were characterized. The optimum pH was 6.0 for the prepared poly(vinyl chloride) membrane and carbon paste electrodes. The limit of detection of the poly(vinyl chloride) membrane electrode was 0.49x10(-8)mM, with the linear dynamic range from 1.0x10(-5) to 1.0x10(-9)mM. The response time for the membrane electrode was 2min and the operational lifetime was 23 weeks. For the carbon paste electrode, the limit of detection was 0.91x10(-8)mM, the linear dynamic range was from 1.0x10(-4) to 1.0x10(-9)mM, the response time was 1min, and the operational lifetime was 24 weeks.