Voltammetry and amperometric detection of tetracyclines at multi-wall carbon nanotube modified electrodes

Abstract

The voltammetric behaviour and amperometric detection of tetracycline (TC) antibiotics at multi-wall carbon nanotube modified glassy carbon electrodes (MWCNT-GCE) are reported. Cyclic voltammograms of TCs showed enhanced oxidation responses at the MWCNT-GCE with respect to the bare GCE, attributable to the increased active electrode surface area. Hydrodynamic voltammograms obtained by flow-injection with amperometric detection at the MWCNT-GCE led us to select a potential value E(det) = +1.20 V. The repeatability of the amperometric responses was much better than that achieved with bare GCE (RSD ranged from 7 to 12%), with RSD values for i (p) of around 3%, thus demonstrating the antifouling capability of MWCNT modified electrodes. An HPLC method with amperometric electrochemical detection (ED) at the MWCNT-GCE was developed for tetracycline, oxytetracycline (OTC), chlortetracycline and doxycycline (DC). A mobile phase consisting of 18:82 acetonitrile/0.05 mol L(-1) phosphate buffer of pH 2.5 was selected. The limits of detection ranged from 0.09 micromol L(-1) for OTC to 0.44 micromol L(-1) for DC. The possibility to carry out multiresidue analysis is demonstrated. The HPLC-ED/MWCNT-GCE method was applied to the analysis of fish farm pool water and underground well water samples spiked with the four TCs at 2.0 x 10(-7) mol L(-1). Solid-phase extraction was accomplished for the preconcentration of the analytes and clean-up of the samples. Recoveries ranged from 87 +/- 6 to 99 +/- 3%. Under preconcentration conditions, limits of detection in the water samples were between 0.50 and 3.10 ng mL(-1).

A novel colorimetric aptasensor using gold nanoparticle for a highly sensitive and specific detection of oxytetracycline

“…Therefore, there have been lots of efforts to develop the sensitive and selective biosensor systems for detection of these antibiotics in contaminated food products and pharmaceutical preparations. However, the previously reported methods such as dipstick colorimetric method (Link et al, 2007), amperometric detection method using multi-wall carbon nanotubes (Vega et al, 2007), and antibody-based colorimetric methods (Weber et al, 2005) were found to be neither specific nor sensitive, due to the high structural similarity of TC derivatives, which could be a hurdle in their selective recognitions.…”

Electrochemical aptasensor for tetracycline detection

“…However, this method is neither sensitive for detection of TCs nor distinguishes the other members of TET derivatives in contaminants. In another study, an improved amperometric detection method for TCs was reported by using multi-wall carbon nanotube-modified electrodes (detection limit: 0.09-0.44 lM of oxytetracycline) [15]. Immune-based colorimetric methods employing ELISA-type format which utilize antibodies had the detection limit of TCs in ng/mL range [16], but these sensitive detection techniques for TCs are often expensive, labor intensive, and time-consuming.…”

Electrochemical Determination of Tetracycline Using Molecularly Imprinted Polymer Modified Carbon Nanotube‐Gold Nanoparticles Electrode

“…The oxidation of tetracycline (TC) has been reported by gold [12], ruthenium oxide-hexacyanoruthenate (RuO-RuCN) [13] or multiwall carbon nanotubes (MWNTs) [14] modified electrodes. However, the tetracycline antibiotics, such as tetracycline, chlortetracycline and oxytetracycline, contain the same phenolic and di(methyl)amino substituents.…”