Electrocatalytic Activity of 3-Dimensional Ordered Macroporous Gold Electrode-Based Lactate Biosensors Platforms as a Function of Pore Layer Number

• Published in: Electroanalysis (New York, N.Y.) N.Y.), 2013-01, Vol.25 (1), p.179-188
• Main Authors: Gamero, M., Fierro, J. L. G., Lorenzo, E., Alonso, C.
• Format: Article
• Language: English
• Subjects: 3D ordered macroporous gold electrode; Atomic force microscopy (AFM); Electrochemical impedance spectroscopy (EIS); Lactate oxidase biosensor; X-ray photoelectron spectroscopy (XPS)
• ISSN: 1040-0397; 1521-4109
• DOI: 10.1002/elan.201200419

We report the electrocatalytic response of a lactate biosensor, based on a 3‐dimensional ordered macroporous (3DOM) gold electrode, as a function of the pore layer number. The biosensor was developed by covalent immobilization of lactate oxidase (LOx) to a self‐assembled monolayer of dithiobis‐N‐succinimidyl propionate (DTSP). The binding of DTSP to the gold surface was studied by X‐ray photoelectron spectroscopy (XPS), indicating the existence of SAu bonds. The DTSP coverage and the different steps followed in the construction of the biosensor were examined by electrochemical impedance spectroscopy (EIS). The catalytic response to a 14 mM lactate concentration, increased linearly with the pore layer number of the 3DOM gold electrode, reaching a value 3 times higher, than for polycrystalline gold electrodes, for 7.5 layers.