Hydrogen Peroxide Biosensor with a Supramolecular Layer-by-Layer Design

• Published in: Langmuir Vol. 24; no. 15; pp. 7654 - 7657
• Main Authors: Camacho, Conrado, Matías, Juan C, Cao, Roberto, Matos, Madyu, Chico, Belkis, Hernández, Javier, Longo, Maria A, Sanromán, Maria A, Villalonga, Reynaldo
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 05-08-2008
• Subjects: Biosensing Techniques; Chemistry; Colloidal state and disperse state; Cyclodextrins - chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Horseradish Peroxidase - metabolism; Hydrogen Peroxide - chemistry; Surface physical chemistry; Hydrogen peroxide; Enzyme; Immobilization; Polymer; Design; Electrodes; Hydroquinone; Cyclic voltammetry; Cyclodextrin; Storage; Peroxidases; Residue; Biosensor; Detection limit; Electrochemistry; Peroxidase; Oxidoreductases
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la800242a

A new sensor design is reported for the construction of an amperometric enzyme biosensor toward H2O2. It was based in the supramolecular immobilization of alternating layers of horseradish peroxidase (either modified with 1-adamantane or β-cyclodextrin-branched carboxymethylcellulose residues) on Au electrodes coated with polythiolated β-cyclodextrin polymer. The analytical response of the electrodes, using 1 mM hydroquinone as an electrochemical mediator, increases when the number of enzyme layers increases. The biosensor having three enzyme layers showed a sensitivity of 720 μA/M cm2 and a detection limit of 2 μM and retained 96% of its initial activity after 30 days of storage. The host−guest supramolecular nature of the immobilization method was confirmed by cyclic voltammetry.