Antibiotic Detection in Urine Using Electrochemical Sensors Based on Vertically Aligned Carbon Nanotubes

Authors

  • Fernando C. Moraes,

    1. Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
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  • Tiago A. Silva,

    1. Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
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  • Ivana Cesarino,

    Corresponding author
    1. Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
    • Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
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  • Marcos R. V. Lanza,

    1. Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
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  • Sergio A. S. Machado

    1. Instituto de Química de São Carlos, Universidade de São Paulo, C.P. 780, 13560-970, São Carlos, SP, Brazil tel: +55 16 33739924
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Abstract

A sensitive way to determine levofloxacin using a sensor based on vertical aligned carbon nanotubes is described. The morphology and the electrochemical performance of the electrodes were characterised by atomic force microscopy, cyclic voltammetry and square wave voltammetry. A scan-rate study and electrochemical impedance spectroscopy showed that the levofloxacin oxidation product is adsorbed on the electrode surface. Differential pulse voltammetry in phosphate-buffer solution allowed the development of a method to determine levofloxacin levels in the range of 1.0–10.0 µmol L−1, with a detection limit of 75.2 nmol L−1. The proposed sensor was successfully applied in the determination of levofloxacin in urine, and the obtained results were in full agreement with those from the HPLC procedure.

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