Graphite/SiO2 film electrode modified with hybrid organic-inorganic perovskites: Synthesis, optical, electrochemical properties and application in electrochemical sensing of losartan

The Use of Electrochemical Voltammetric Techniques and High-Pressure Liquid Chromatography to Evaluate Conjugation Efficiency of Multiple Sclerosis Peptide-Carrier Conjugates

“…All these features are crucial for the correct choice of a working electrode, especially when direct electrochemistry is conducted [ 1 ]. We recently demonstrated that these film electrodes modified or not, could be used for electrochemical drug sensing, for validation in food chemistry, and for the immobilization of heme proteins for studying protein/electrode interaction [ 2 , 3 , 4 ]. The electrochemical analytical methods were recently applied effectively in the detection of anti-hypertensive drug losartan [ 3 ] and have applied this method to detect peptides in peptide-carrier conjugates.…”

“…Numerous methods have been established for the analytical determination of drugs at low concentrations, using state of the art systems, such as HPLC, high-performance thin-layer chromatography and capillary electrophoresis/capillary electrochromatography [ 3 ]. Although these methods provide very accurate and reliable data, they are costly, time consuming, and involve the use of expensive equipment and consumables.…”

“…In this sense, electrochemical methods have emerged as low cost, reliable alternatives for the characterization of peptides and drugs. Different electrochemical techniques, involving voltammetry or potentiometry, have been implemented for drug analysis, as they offer ease of preparation and operation, high sensitivity, fast response time, high quantification and detection limits, reasonable selectivity, wide linear range, and are cost effective [ 3 ]. In this regard, we applied voltammetry techniques to monitor the conjugation of a peptide to its carrier, for the first time as a proof of concept study.…”

“…As such, mannan was used as a carrier and conjugated to immunodominant MS peptides including MBP 83-99 , PLP 139-141 , and MOG 35-55 or their analogues, and were shown in animal models to tolerize T cells or switch Th1 cells to Th2 cells, depending on the peptide analogue used and showed stimulation of Th2 cells in peripheral blood mononuclear cells from patients with MS [ 17 , 21 , 33 , 34 , 35 ]. The conjugation of mannan, in its oxidized form (OM), to MOG 35-55 peptide (MOG 35-55 was used as an example in this study) via a (Lys-Gly) 5 linker [(KG) 5 ] was used and evaluated (OM-(KG) 5 -MOG 35-55 conjugate) using voltammetric techniques [ 1 , 2 , 3 , 4 , 36 , 37 , 38 ]. The conjugation between OM and peptide (MOG 35-55 ) occurs via formation of Schiff bases between the free amines of the linker (KG) 5 and aldehydes of OM.…”

Electrochemistry: Modified Electrodes and their Potentialities

“…Atualmente, observa-se um aumento no interesse de estudos referentes aos eletrodos com maior reprodutibilidade, baixo custo, miniaturização, portáteis, de fácil manuseio e com elevada capacidade analítica. [77][78][79][80][81] Os eletrodos impressos (EI), esquematizado na Figura 7, além de atender a esses pré-requisitos, permitem a automação na fabricação, por conterem os eletrodos de trabalho, auxiliar e de referência em um mesmo suporte. [82][83][84][85][86] As aplicações podem se estender a diferentes tipos de modificadores, 87 como por exemplo, eletrodos impressos em tela para controle de qualidade de combustíveis líquidos 88 e análises clínicas.…”