Direct cefepime determination in human milk using solid mercury amalgam electrode manufactured with silver nanoparticles

New approaches in antibiotics detection: The use of square wave voltammetry

Antibiotics belongs to a class of pharmaceutical compounds widely used due to their effectiveness against bacterial infections. However, if consumed or inappropriately disposed of in the environment can results in environmental and public health problems, because they are considered emerging contaminants and their residues represent damage, whether in the long or short term, to different terrestrial ecosystems, in addition to bringing potential risks to agricultural sectors, such as livestock and fish farming. For this, the development of analytical methods for low-concentration detection and identification of antibiotics in natural waters, wastewaters, soil, foods, and biological fluids is necessary. This review shows the applicability of square wave voltammetry for the analytical determination of antibiotics from different chemical classes and covers a variety of samples and working electrodes that are used as voltammetric sensors. The review involved the analysis of scientific publications from the Science Direct® and Scopus® databases, with scientific manuscripts covering the period between January 2012 and May 2023. Various manuscripts were discussed indicating the applicability of square wave voltammetry in antibiotics detection in urine, blood, natural waters, milk, among other complex samples.

Electrochemical Methods for the Analysis of Milk

The milk and dairy industries are some of the most profitable sectors in many countries. This business requires close control of product quality and continuous testing to ensure the safety of the consumers. The potential risk of contaminants or degradation products and undesirable chemicals necessitates the use of fast, reliable detection tools to make immediate production decisions. This review covers studies on the application of electrochemical methods to milk (i.e., voltammetric and amperometric) to quantify different analytes, as reported over the last 10 to 15 years. The review covers a wide range of analytes, including allergens, antioxidants, organic compounds, nitrogen- and aldehyde containing compounds, biochemicals, heavy metals, hydrogen peroxide, nitrite, and endocrine disruptors. The review also examines pretreatment procedures applied to milk samples and the use of novel sensor materials. Final perspectives are provided on the future of cost-effective and easy-to-use electrochemical sensors and their advantages over conventional methods.

Recent Electrochemical Assays on Cephalosporins

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Antibiotics are an important class among drugs because they are a significant agent to deal with infections. Cephalosporins are a very important group of antibiotics in the β-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalosporium. Cephalosporins are classified as first, second, third, fourth, and advanced generation, based largely on their antibacterial spectrum and stability to β-lactamases. Electrochemical methods have been used for the determination of cephalosporin just as used in the determination of many antibiotic drugs. Electroanalytical methods present generally high sensitivity, low cost, low requirements, ease of preparation of the samples in a very short time, and a short analysis time. The most commonly used types are cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and linear sweep voltammetry. The aim of this review is to evaluate the advantages and uses of electroanalytical methods used in the determination of cephalosporins. In addition, current applications of the methods to the pharmaceutical analysis of cephalosporins will also be summarized in a table.

Electrochemical immunosensor based on carboxylated single-walled carbon nanotube-chitosan functional layer for the detection of cephalexin

In this study, a sensitive and selective electrochemical immunosensor for cephalexin (CEX) determination on a glassy carbon electrode (GCE) surface was modified by a carboxylated single-walled carbon nanotubes/chitosan (SWNTs-COOH/CS) composite. The SWNTs-COOH/CS composite was used to enhance sensor performance and to enlarge the electrochemical response of CEX. The cephalosporin-ovalbumin coupling (CEX-OVA) was synthesized using the reactive ester method. The free CEX in solution could be effectively measured based on the competitive immunoreaction between CEX-antibody and CEX. Under optimal conditions, the electrochemical immunosensor offered an excellent response for CEX. The linear range was 1-800 ng/ml, with a detection limit of 45.7 ng/ml (S/N = 3). This method was applied to determine CEX in six different samples and obtained the recovery range from 80.15% to 94.04%. These results indicated that the fabricated electrochemical immunosensor and sensing method are suitable for quantification of CEX in real samples. These have great potential for wider applications in environmental and agri-food products industries.