title: A novel electrochemical sensor based on metal-organic framework for electro-catalytic oxidation of L-cysteine.
abstract: A novel electrochemical sensor based on Au-SH-SiO₂ nanoparticles supported on metal-organic framework (Au-SH-SiO₂@Cu-MOF) has been developed for electrocatalytic oxidation and determination of L-cysteine. The Au-SH-SiO₂@Cu-MOF was characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction and cyclic voltammetry. The electrochemical behavior of L-cysteine at the Au-SH-SiO₂@Cu-MOF was investigated by cyclic voltammetry. The Au-SH-SiO₂@Cu-MOF showed a very efficient electrocatalytic activity for the oxidation of L-cysteine in 0.1 M phosphate buffer solution (pH 5.0). The oxidation overpotentials of L-cysteine decreased significantly and their oxidation peak currents increased dramatically at Au-SH-SiO₂@Cu-MOF. The potential utility of the sensor was demonstrated by applying it to the analytical determination of L-cysteine concentration. The results showed that the electrocatalytic current increased linearly with the L-cysteine concentration in the range of 0.02-300 μM and the detection limit was 0.008 μM. Finally, the sensor was applied to determine L-cysteine in water and biological samples.
authors.affiliation: Department of Chemistry, Shahid Beheshti University, G.C., P. O. Box 19396-4716, Tehran, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Hosseini
authors.forename: Hamid
authors.initials: H
authors.lastname: Ahmar
authors.forename: Ali
authors.initials: A
authors.lastname: Dehghani
authors.forename: Akbar
authors.initials: A
authors.lastname: Bagheri
authors.forename: Azadeh
authors.initials: A
authors.lastname: Tadjarodi
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Fakhari
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003545:Cysteine / Q000737:chemistry / Q000302:isolation & purification*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction
chemical_list: D006046:Gold; D003545:Cysteine