Voltammetric Determination of Sulfonamides with a Modified Glassy Carbon Electrode Using Carboxyl Multiwalled Carbon Nanotubes

Abstract

New glassy carbon electrode (GCE) modified with carboxyl multiwalled carbon nanotubes (MWCNTs) and treated with ultrasonic dispersing in N,N-dimethylfomamide (DMF) media, namely DMF/carboxyl/MWCNTs/GCE, was prepared for electrochemical determination of sulfonamides (SAs). Electrochemical behavior of SAs based on DMF/carboxyl/MWCNTs/GCE was investigated by cyclic voltammetry and impedance spectroscopy. The effects of various experimental parameters on the response of electrode such as pH of buffer, scan rate and the amount of modification were optimized. Under the optimal conditions, the obtained sensor presented linear response to SAs in the range of 5.0 × 10 −7 to 1.1 × 10 −4 mol L −1 of sulfonamide (R = 0.999), sulfamethazine (R = 0.990), sulfadiazine (R = 0.997), sulfamethoxazole (R = 0.996) and the limits of detection of 1. 65 × 10 −8 , 3.19 × 10 −8 , 6.76 × 10 −8 and 9.41 × 10 −8 mol L −1 , respectively. The recoveries were in the range of ca. 85-103% with relative standard deviation (RSD) < 5%. The sensor was tested by cyclic voltammetry with repeatability and stability of more than 90% of its original activity. The proposed method might offer feasibility and applicability of the sensor for further complex sulfonamides compounds.Keywords: voltammetric determination, carboxyl, multiwalled carbon nanotubes, sulfamethazine, sulfamethoxazole Introduction Sulfonamides (SAs) have a broad spectrum of antibacterial activity and play an important role as effective chemotherapeutics in bacterial. The structures of SAs consist of benzene ring with amine group (NH 2 ) at a C4 position and sulfonic acid with different alkyl groups (Figure 1). They are widely used in animal husbandry with the purpose to prevent the growth of bacteria, to treat the infections from certain protozoa and microorganisms 1,2 and to increase their production.3 As an additive of preventing bacterial in animal feed, 4 SAs, however, would bring potential consequences with unauthorized use.3 The drug residues in foods, such as milk and meat, may cause allergic reactions, antibiotic resistance and even cancer. Many countries including China have established maximum residue limits (MRLs) for SAs at the total level of 100 μg kg −1 in animal meat. 5Consequently, it is of grave importance to develop a rapid, sensitive, and accurate method for monitoring the level of SAs residues in animal meat.Currently, various methods, such as liquid chromatography, 6-12 capillary electrophoresis, 13-16 gas chromatography (GC), 17-19 micellar electrokinetic capillary chromatography, [19][20][21][22] and liquid mass chromatography, 23,24 have been proposed for analyzing SAs residue in food. These techniques have been proved to be suitable and sensitive for SAs detection. Nonetheless, some of these methods are expensive, time-consuming and tedious, and in some cases the limits of detection is not acceptable. Recently, a research on high-performance liquid chromatography (HPLC), which was coupled with photodiode array detector and mass spectrometry, studied for the...

Heme Protein Binding of Sulfonamide Compounds: A Correlation Study by Spectroscopic, Calorimetric, and Computational Methods

“…2,3 These are used for the treatment of bacterial and fungal infections. 4 SMZ and SDZ are also widely used in veterinary medicine to promote growth in animal feed and play major roles in livestock, aquaculture, and pharmaceutical industries. 5−7 These, along with some of their metabolites, are among the most commonly used antibiotics that have been detected in wastewaters.…”

“…Sulfamethazine (SMZ) and sulfadiazine (SDZ) are sulfonamide antibiotics having extensive antibacterial activities . The structure of SNs contains −SO 2 NH 2 or −SO 2 NH– groups with distinct five- or six-membered heterocyclic rings; there are presently many derivatives under the same group of drugs, while some are newly emerging. , These are used for the treatment of bacterial and fungal infections . SMZ and SDZ are also widely used in veterinary medicine to promote growth in animal feed and play major roles in livestock, aquaculture, and pharmaceutical industries. − These, along with some of their metabolites, are among the most commonly used antibiotics that have been detected in wastewaters. , Bacterial resistance and toxicity of these drugs can cause a genuinely negative impact on human well-being and the environment. − Sulfamethazine (Figure A) and sulfadiazine (Figure B) are not well-disposed and have serious side effects that can cause prompt indisposition in humans, such as central nervous system disorders, urinary tract disorders, hemopoiesis, porphyria, and extreme touchiness responses.…”

Electrochemical Characterisation of the Redox Couple of Fe(II)/Fe(III) Mediated by Nano SiO2 Modified GCE Using Cyclic Voltammetry

“…It is scientifically known that different pH values effect directly on the oxidation-reduction current peaks of FeII/FeIII ions in KCl as electrolyte on nano-sensors SiO 2 NPs/GCE [23]. The electrochemical analysis of FeII/FeIII ions in both acidic (pH = 2) and alkaline (pH = 12) is shown in Fig.…”

Evaluation of a Nanocomposite Based on Reduced Graphene Oxide and Gold Nanoparticles as an Electrochemical Platform for Detection of Sulfamethazine

“…Rao et al [12], using a diamond electrode with amperometric detection, found a high LOD of 0.05 µmol L −1 . Using carboxyl multiwalled carbon nanotubes to modify a glassy carbon electrode, the LOD of 0.032 µmol L −1 was determined by He et al [13]. Fotouhi et al [14] found a LOD of 6.1 µmol L −1 using a multiwalled nanotube film-coated glassy carbon electrode.…”