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

Abstract

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.

A Redox-Probe-Free Immunosensor Based on Electrocatalytic Prussian Blue Nanostructured Film One-Step-Prepared for Zika Virus Diagnosis

“…Yu et al (2020) reported that the binding of CNTs to CHI occurs through adsorption by the carboxyl groups of the CNTs to the amine groups of the CHI. Although a uniform nanocomposite was observed, forming a homogeneous film with a greater surface area at the expense of the nanomaterial, the insulating nature of the CHI was predominant and therefore reduced the electrocatalytic activity [ 40 ]. To promote electrocatalytic activity by the adsorption of a redox species to the film, PB was added to the CHI–CNT film, and the synthesis was carried out in two ways, either by mixing the three compounds simultaneously or by adding the PB after the dispersion of the compounds.…”

A new NiS nanoparticle‐enhanced chemiluminescence method for determination of cephalexin in pharmaceuticals and spiked human serum

“…For comparison, the analytical performance of some previously reported methods in addition to the proposed CL method for determination of CEF are summarized in Table 2. The analytical figures of merit of the proposed method are superior to amperometry [3] , spectrophotometry [6] , and CE [8] and are inferior to DPV [4] , potentiometry [5] , HPLC [7] ,…”

“…reactions used in CL methods for determination of CEF are [Ru (bpy) 3 ] 2+ -KMnO 4 [10] , glyoxal-KMnO 4 [11] , and luminol-KIO 4 . [12] In all of these CL reactions, the onset of the reaction depends on adding an external oxidant, including KMnO 4 or KIO 4 . The luminol-O 2 CL reaction is a reaction in which only dissolution of luminol in an alkaline solution is sufficient for the CL reaction to occur.…”

Enhanced and selective electrochemical sensing of cephalexin using zeolite/CPE

“…To date, different detection methods have been developed for cephalexin, including chromatography, 1,2 colorimetry, 3,4 spectrometry, [5][6][7][8] and electrochemical. [9][10][11] Among these methods, the electrochemical approach can be a proper candidate owing to its simplicity, high speed, high sensitivity and selectivity, cost efficiency, and low-amount detection ability. 12 Given the aforementioned benefits, researchers are increasingly using the electrochemical detection of different drugs in solution media.…”