title: An improved biosensor for acetaldehyde determination using a bienzymatic strategy at poly(neutral red) modified carbon film electrodes.
abstract: Improved biosensors for acetaldehyde determination have been developed using a bienzymatic strategy, based on a mediator-modified carbon film electrode and co-immobilisation of NADH oxidase and aldehyde dehydrogenase. Modification of the carbon film electrode with poly(neutral red) mediator resulted in a sensitive, low-cost and reliable NADH detector. Immobilisation of the enzymes was performed using encapsulation in a sol-gel matrix or cross-linking with glutaraldehyde. The bienzymatic biosensors were characterized by studying the influence of pH, applied potential and co-factors. The sol-gel and glutaraldehyde biosensors showed a linear response up to 60 microM and 100 microM, respectively, with detection limits of 2.6 microM and 3.3 microM and sensitivities were 1.7 microA mM(-1) and 5.6 microA mM(-1). The optimised biosensors showed good stability and good selectivity and have been tested for application for the determination of acetaldehyde in natural samples such as wine.
authors: Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal.
authors: Mariana Emilia
authors: ME
authors: Ghica
authors: Rasa
authors: R
authors: Pauliukaite
authors: Nicolas
authors: N
authors: Marchand
authors: Eric
authors: E
authors: Devic
authors: Christopher M A
authors: CM
authors: Brett
mesh_terms: D000079:Acetaldehyde / Q000032:analysis*; D000445:Aldehyde Oxidoreductases / Q000737:chemistry*; D015374:Biosensing Techniques; D002244:Carbon; D004396:Coloring Agents; D003432:Cross-Linking Reagents / Q000737:chemistry; D004566:Electrodes; D004800:Enzymes, Immobilized; D005782:Gels; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009097:Multienzyme Complexes / Q000737:chemistry*; D009243:NAD / Q000032:analysis; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry*; D009499:Neutral Red; D010084:Oxidation-Reduction; D011108:Polymers; D012680:Sensitivity and Specificity; D014920:Wine / Q000032:analysis
chemical_list: D004396:Coloring Agents; D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D005782:Gels; D009097:Multienzyme Complexes; D011108:Polymers; D009243:NAD; D009499:Neutral Red; D002244:Carbon; D000445:Aldehyde Oxidoreductases; C018699:aldehyde dehydrogenase (NAD(P)+); C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D000079:Acetaldehyde; D005976:Glutaral