Determination ofl- and d-fucose using amperometric electrodes based on diamond paste

Abstract

Monocrystalline diamond (natural diamond, synthetic-1 and synthetic-2) based electrochemical electrodes were designed for the analysis of L- and D-fucose. Response characteristics of the electrochemical electrodes were determined using cyclic voltammetry and differential pulse voltammetry (DPV). L-fucose was determined using DPV with electrodes based on natural diamond, synthetic-1 and synthetic-2, respectively, at 240 mV using NaCl as the electrolyte (pH 3.0); at 160 mV using KNO(3) (pH 10.0) and at 80 mV using KCl as the electrolyte (pH 10.0) while D-fucose was analyzed at 120 mV using KCl as the electrolyte (pH 1.0); at 140 mV using KNO(3) as the electrolyte (pH 1.0) and at 160 mV using NaNO(3) as the electrolyte (pH 3.0). The linear concentration ranges for L-fucose were between 10(-13) and 10(-9) mol L(-1) (natural diamond), 10(-11) and 10(-8) mol L(-1) (synthetic-1) and 10(-6) and 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-14), 10(-12) and 10(-8) mol L(-1) magnitude order, respectively. For D-fucose, the linear concentration ranges were 10(-6) to 10(-3) mol L(-1) (natural diamond), 10(-5) to 10(-3) mol L(-1) (synthetic-1) and 10(-9) to 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-7), 10(-7) and 10(-10) mol L(-1) magnitude order, respectively. The sensors were used for the assay of L-fucose in serum and urine samples.

Chiral Recognition of Proline Enantiomers by the Catalytic Oxygen Reduction and Formation of Cu(II)‐Polymer Complex Crystals

“…Another method based on electrochemistry in a non-aqueous medium is also available for the discrimination of chiral molecules using polypyrrole as a backbone with chiral side chains [14]. A single crystal diamond electrode has also recently been used for the analysis of l-and d-fucose [15]. However, these methods either require the use of a non-aqueous medium and a lengthy procedure to attach the chiral moiety on the monomer side chain [16,17] or the determination of the two isomers is conducted under different conditions.…”

Pattern recognition of estradiol, testosterone and dihydrotestosterone in children's saliva samples using stochastic microsensors

“…Their utilization in biomedical analysis represents a good alternative to chromatographic methods1213141516171819202122. Stochastic response is based on channel conductivity, according to the mechanism described previously by Stefan-van Staden and Moldoveanu21.…”

“…The monocrystalline form of diamond was preferred due to the diamond monocrystal properties proprieties, such as enhanced holes and electron mobilities2526. Monocrystallin diamond paste sensors have been used in differential potentiometric voltammetry mode for the assay of biological compounds such as: L-fucose and D-fucose15, sildenafil citrate1314, and neurotransmitters16171819. To our knowledge, the approach has not been used previously to assay steroid hormones in biological matrices such as saliva.…”