Selective and sensitive voltammetric sensor based on modified multiwall carbon nanotubes paste electrode for simultaneous determination of l-cysteine and folic acid

A nanostructure-based electrochemical sensor for square wave voltammetric determination of N-acetylcysteine in pharmaceutical and biological samples

“…However, in the presence of N-AC, the charge value associated with forward chronocoloumetry was significantly greater than that observed for backward chronocoloumetry. This behavior is typical of that expected for electrocatalysis of chemically modified electrodes [41]. Figure 7 compares the Nyquist diagram of the electrodes recorded in PBS (pH 7.0) containing 300 μM N-AC (b) and without N-AC (a).…”

A Solid Film Electrode of Intermetallic Ag2Hg3.02 for the Direct Determination of Folic Acid in Fresh and Processed Fruit Juices

“…8 acid [16], gold nanoparticles-modified carbon paste electrode (AuNPs/CPE) [17], ethynylferrocene modified carbon nanotubes paste electrode [18], carbon nanotube paste electrode (PBDCNPE) with 2,2'-[1,2-phenylenediylbis(nitrilomethylidene)]bis(4-hydroxyphenol) [19]. The detection limits obtained in these studies were in the level of 10 À6 to 10 À9 mol L À1 and sometimes the fabrication process associated with chemical modified electrodes is typically both time-consuming and laborious.…”

A Nanostructure Based Electrochemical Sensor for Square Wave Voltammetric Determination of L‐Cysteine in the Presence of High Concentration of Folic Acid

“…Generally,t he determination of Cys is carried out by various methods,i ncluding chromatography [2-4], electrophoresis [5],s pectrophotometry [6-9],a nd chemiluminescence [10].C ys can be studied also via electrochemical techniques [11][12][13][14].Combination of Cys and FA are effective against signs of aging and also Cys is effective on the FA conjugation [12].S o, simultaneous determination of thesec ompounds is very important in biological samples.T ot he best of our knowledge,o nly one published paper has been reported on the voltammetric determination of Cysi nt he presence of FA using modified electrodes [12],w hich is the focus of the present study.C ompared with previous report, the sensor usedi nt his study has an excellent dynamic range and limit of detection for the Cysa nalysis in the simultaneous determination of Cys and FA.Compared with otherk ind of sensors,e lectrochemical sensors have manya dvantages.F or example,t he electrodes can sense the materials whicha re present within the host without doinga ny damage to the host system [15][16][17][18][19][20][21][22][23][24].O nt he other hand, the active sensing material on the electrode should act as ac atalyst and catalyze the reaction of the biochemical or food electroactive compounds to obtain the output signals [25,26].T he selection and de-velopment of an active material in electrochemical studies is an important issue.T he actives ensingm aterials maybe of any kind as whichever acts as ac atalyst for sensing ap articular analyte or as et of analytes.T he recent improvement in the nanoscience has paved the way for large number of new materials and devices of desirable properties whichh ave useful functions for numerous electrochemical sensors and biosensor applications [27][28][29].In this research, we have used cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and SWV as voltammetric techniques for electrochemical determinationo fC ys on the DMBQ/ZnO/NPs/CPE at pH 5.0. l-Cys is built directly from l-methionin as an essential aminoacid making its abundance in the body acritical factor to the bodys supply of l-cysteine.…”

“…Generally,t he determination of Cys is carried out by various methods,i ncluding chromatography [2-4], electrophoresis [5],s pectrophotometry [6-9],a nd chemiluminescence [10].C ys can be studied also via electrochemical techniques [11][12][13][14]. l-Cys is built directly from l-methionin as an essential aminoacid making its abundance in the body acritical factor to the bodys supply of l-cysteine.…”