Improved Voltammetric Response of L‐Tyrosine on Multiwalled Carbon Nanotubes‐Ionic Liquid Composite Coated Glassy Electrodes in the Presence of Cupric Ion

Abstract

l-Tyrosine can exhibit a small anodic peak on multiwalled carbon nanotubes (MWCNTs) coated glassy carbon electrodes (GCE). At pH 5.5 its peak potential is 0.70 V (vs. SCE). When an ionic liquid (i.e., 1-octyl-3-methylimidazolium hexafluorophosphate, [omim][PF 6 ]) is introduced on the MWCNT coat, the peak becomes bigger. Furthermore, in the presence of Cu 2þ ion the anodic peak of l-tyrosine increases further due to the formation of Cu 2þ -l-tyrosine complex, while the peak potential keeps unchanged. Therefore, a sensitive voltammetry based on the oxidation of Cu 2þ -l-tyrosine complex on MWCNTs-[omim] [PF 6 ] composite coated electrode is developed for ltyrosine. Under the optimized conditions, the anodic peak current is linear to l-tyrosine concentration in the range of 1 Â 10 À8 -5 Â 10 À6 M, and the detection limit is 8 Â 10 À9 M. The modified electrode shows good reproducibility and stability. In addition, the voltammetric behavior of other amino acids is explored. It is found that among them tryptophan (Trp) and histidine (His) can also produce sensitive anodic peak under same experimental conditions, and their detection limits are 4 Â 10 À9 M and 4 Â 10 À6 M, respectively.

A review on electrodes modified with ionic liquids

“…These reagents include inorganic anions as nitrite [147][148][149], nitrate [115], iodate [107] or gases like nitric oxide [150]. There is also large group pf organic analytes as chloramphenicol [151], 4-chloronitrobenzene [152], 4-nitrophenol [106] or biomolecules as L-tyrosine [153], cysteine [108], NADH [154], glucose [67], cholesterol [155] and DNA [146] which can be determined with these electrodes. They are also used for stripping voltammetry of trace metal ions employing their high solubility in IL [156].…”

Electroanalytical Sensor for Diabetic Foot Ulcer Monitoring with Integrated Electronics for Connected Health Application

“…The exploitation of nanomaterials in electrochemical bio-sensors have been intensively explored owing to enhanced surface to volume ratio, thereby opening prospects of diverse functionalization, and quantum confinement effects [15][16][17][18][19][20]. Among the vast array of nanomaterials, MnO 2 nanostructures have garnered considerable interest due to its non-toxic nature which makes them potential biocompatible sensing platforms [21][22][23].…”

First Electrochemical Report for Simultaneous Determination of Norepinephrine, Tyrosine and Nicotine Using a Nanostructure Based Sensor

“…However, sister chromatid exchange increases due to a high concentration of L‐tyrosine 30. Therefore, it has the vital clinical significance for the accurate determination of L‐tyrosine 31–36.…”