Voltammetri c determination of L-cystei ne using modified electrode with multi-wall carbo n nanotu bes and ۳,۴-dihydroxycinnamic acid

Two o f these are sulfur-containing amino acids; cysteine an d methionine. The only trait differen tiating cysteine from serine is the sulfur of its thiol replacing the oxyge n of the alcohol. Cysteine plays an important role in stabilizing extracellular proteins. It can also react with it self to for m an oxidi zed dimer by forming a disulfid e bond. The thiol residue of cysteine is readil y oxidized in electroc hemical re actions at the surface of variou s thiol-sensitive electrode s [۱]. Different meth ods have been reported for the d eterminatio n of L-cysteine in diffe rent samples. Howev er, Long response time, expensive instr uments, compli cated procedure, and low detection capabili ty are the shortcomin gs associa ted with most su ch method s reported.Carbon nanotubes (CNT) are an important nano structural that used building blocks of nanotec hnology. C NTs have generated great intere st for future applications based on their field e mission and electronic transport properties, their high mechanical strength and high conductivity [۲]. The modification of electrode substrates with CNTs for use in a nalytical sensing has been d ocumented to result in low detection limits, high sensitivities, redu ction of over-po tentials, and resistanc e to surface fouling.

کلیدواژه ها:

L-Cysteine ، Multiwall carb on nanotubes ، Voltam metry ، ۳ ، ۴- Dihydroxycinnamic acid.