Portal de Periódicos da CAPES

Electrochemical Sensor for Electrochemically Inactive β- d (+)-Glucose Using α-Cyclodextrin Template Molecules

2002; American Chemical Society; Volume: 74; Issue: 9 Linguagem: Inglês

10.1021/ac0107913

1520-6882

Shin-Jung Choi, Bo-Geum Choi, Su‐Moon Park,

Ionic liquids properties and applications

We report an electrochemical sensor for an electrochemically inactive organic compound using a self-assembled monolayer (SAM) formed on the gold surface from a solution of thiolated α-cyclodextrin (α-CD). The SAM makes up an array of ultramicroelectrodes, which capture electroactive molecules such as those of ferrocene. When this SAM-modified electrode is exposed to a solution containing an electrochemically inactive compound, e.g., glucose, the captured ferrocene molecules are replaced by the electroinactive molecules via an equilibrium established between the two compounds, lowering the current for ferrocene oxidation. The decrease in current is directly proportional to the amount of glucose added and the glucose can be analyzed up to ∼0.80 mM, which is ∼1/10 of a typical physiological concentration in blood serum. Formation constants of the surface-bound α-CD molecules with ferrocene and glucose are also reported.