Electrocatalytic processes promoted by diamond nanoparticles in enzymatic biosensing devices.
We have developed a biosensing platform for lactate determination based on gold electrodes modified with diamond nanoparticles of 4nm of nominal diameter, employing the enzyme lactate oxidase and (hydroxymethyl)ferrocene (HMF) as redox mediator in solution. This system displays a response towards lactate that is completely different to those typically observed for lactate biosensors based on other nanomaterials, such as graphene, carbon nanotubes, gold nanoparticles or even diamond nanoparticles of greater size. We have observed by cyclic voltammetry that, under certain experimental conditions, an irreversible wave (E(0)=+0.15V) appears concomitantly with the typical Fe(II)/Fe(III) peaks (E(0)=+0.30V) of HMF. In this case, the biosensor response to lactate shows simultaneous electrocatalytic peaks at +0.15V and +0.30V, indicating the concurrence of different feedback mechanisms. The achievement of a biosensor response to lactate at +0.15V is very convenient in order to avoid potential interferences. The developed biosensor presents a linear concentration range from 0.02mM to 1.2mM, a sensitivity of 6.1μAmM(-1), a detection limit of 5.3μM and excellent stability. These analytical properties compare well with those obtained for other lactate-based biosensors that also include nanomaterials and employ HMF as redox mediator.
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Briones
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Petit-Domínguez
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Parra-Alfambra
Instituto de Ciencia de Materiales de Madrid (CSIC), c/ Sor Juana Inés de la Cruz N°3, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Vázquez
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Pariente
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain; Instituto Madrileño de Estudios Avanzados (IMDEA) - Nanoscience, Faraday 9, Campus Cantoblanco-UAM, 28049 Madrid, Spain.
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Lorenzo
Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/ Francisco Tomás y Valiente, N°7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: elena.casero@uam.es.
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Casero
D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D018130:Diamond / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D019344:Lactic Acid / Q000032:analysis / Q000737:chemistry; D000075163:Metallocenes; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry*
D005296:Ferrous Compounds; D000075163:Metallocenes; D019344:Lactic Acid; D006046:Gold; D018130:Diamond; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase; C004998:ferrocene
(Hydroxymethyl)ferrocene; Diamond nanoparticles; Electrochemical biosensors; Lactate determination