title: Diamond nanoparticles based biosensors for efficient glucose and lactate determination.
abstract: In this work, we report the modification of a gold electrode with undoped diamond nanoparticles (DNPs) and its applicability to the fabrication of electrochemical biosensing platforms. DNPs were immobilized onto a gold electrode by direct adsorption and the electrochemical behavior of the resulting DNPs/Au platform was studied. Four well-defined peaks were observed corresponding to the DNPs oxidation/reduction at the underlying gold electrode, which demonstrate that, although undoped DNPs have an insulating character, they show electrochemical activity as a consequence of the presence of different functionalities with unsaturated bonding on their surface. In order to develop a DNPs-based biosensing platform, we have selected glucose oxidase (GOx), as a model enzyme. We have performed an exhaustive study of the different steps involved in the biosensing platform preparation (DNPs/Au and GOx/DNPs/Au systems) by atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and cyclic voltammetry (CV). The glucose biosensor shows a good electrocatalytic response in the presence of (hydroxymethyl)ferrocene as redox mediator. Once the suitability of the prototype system to determine glucose was verified, in a second step, we prepared a similar biosensor, but employing the enzyme lactate oxidase (LOx/DNPs/Au). As far as we know, this is the first electrochemical biosensor for lactate determination that includes DNPs as nanomaterial. A linear concentration range from 0.05 mM to 0.7 mM, a sensitivity of 4.0 µA mM(-1) and a detection limit of 15 µM were obtained.
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain.
authors: M
authors: M
authors: Briones
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain. Electronic address: elena.casero@uam.es.
authors: E
authors: E
authors: Casero
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain.
authors: M D
authors: MD
authors: Petit-Domínguez
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain.
authors: M A
authors: MA
authors: Ruiz
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain.
authors: A M
authors: AM
authors: Parra-Alfambra
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain.
authors: F
authors: F
authors: Pariente
authors: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Campus de Excelencia de la Universidad Autónoma de Madrid, c/Francisco Tomás y Valiente N°7, 28049 Madrid, Spain; Instituto Madrileño de Estudios Avanzados (IMDEA)-Nanoscience, Faraday 9, Campus Cantoblanco-UAM, 28049 Madrid, Spain.
authors: E
authors: E
authors: Lorenzo
authors: Instituto de Ciencia de Materiales de Madrid (CSIC), Campus de Excelencia de la Universidad Autónoma de Madrid, c/Sor Juana Inés de la Cruz N°3, 28049 Madrid, Spain.
authors: L
authors: L
authors: Vázquez
mesh_terms: D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized / Q000737:chemistry; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification*; D005949:Glucose Oxidase / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry / Q000302:isolation & purification*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning
chemical_list: D004800:Enzymes, Immobilized; D019344:Lactic Acid; D006046:Gold; D005949:Glucose Oxidase; D005947:Glucose
keywords: Atomic force microscopy; Diamond nanoparticles; Electrochemical techniques; Glucose biosensor; Lactate biosensor