Selective detection of As(III) at the Au(111)-like polycrystalline gold electrode.
Selective electrochemical detection of As(III) using a highly sensitive platform based on a Au(111)-like surface is described. The Au(111)-like surface was achieved for the first time by the partial reductive desorption of n-butanethiol (n-BT) from polycrystalline gold (poly-Au), on which a self-assembled monolayer (SAM) of n-BT was formed previously, which allows the selective blockage of the Au(100) and Au(110) surface domains by n-BT while the Au(111) domain remains bare. Square wave anodic stripping voltammetry (SWASV) using the Au(111)-like poly-Au electrode confirms the successful detection of As(III) without any interference from Cu(II). The fabricated electrode is stable and highly sensitive even in the presence of Cu(II), and it shows a linear response for As(III) up to 15 μM. The detection limit (S/N = 3) toward As(III) is 0.28 ppb, which is far below the guideline value given by World Health Organization (WHO). The electrode was applicable for the analysis of spiked arsenic in tap water containing a significant amount of various other ion elements. The results indicate that the Au(111)-like poly-Au electrode could be promising for the electrochemical detection of trace level of As(III) in real samples without any interference from Cu(II).
Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-G1-5 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
Mohammad Rezaur
MR
Rahman
Takeyoshi
T
Okajima
Takeo
T
Ohsaka
D001151:Arsenic / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D011108:Polymers; D013438:Sulfhydryl Compounds; D014867:Water; D006046:Gold; D001151:Arsenic; D010100:Oxygen