title: Diamond nanoparticles as a way to improve electron transfer in sol-gel L-lactate biosensing platforms.
abstract: In the present work, we have included for the first time diamond nanoparticles (DNPs) in a sol-gel matrix derived from (3-mercaptopropyl)-trimethoxysilane (MPTS) in order to improve electron transfer in a lactate oxidase (LOx) based electrochemical biosensing platform. Firstly, an exhaustive AFM study, including topographical, surface potential (KFM) and capacitance gradient (CG) measurements, of each step involved in the biosensing platform development was performed. The platform is based on gold electrodes (Au) modified with the sol-gel matrix (Au/MPTS) in which diamond nanoparticles (Au/MPTS/DNPs) and lactate oxidase (Au/MPTS/DNPs/LOx) have been included. For the sake of comparison, we have also characterized a gold electrode directly modified with DNPs (Au/DNPs). Secondly, the electrochemical behavior of a redox mediator (hydroxymethyl-ferrocene, HMF) was evaluated at the platforms mentioned above. The response of Au/MPTS/DNPs/LOx towards lactate was obtained. A linear concentration range from 0.053 mM to 1.6 mM, a sensitivity of 2.6 μA mM(-1) and a detection limit of 16 μM were obtained. These analytical properties are comparable to other biosensors, presenting also as advantages that DNPs are inexpensive, environment-friendly and easy-handled nanomaterials. Finally, the developed biosensor was applied for lactate determination in wine samples.
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/Francisco Tomás y Valiente, Nº7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Briones
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/Francisco Tomás y Valiente, Nº7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Casero
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC), c/Sor Juana Inés de la Cruz Nº3, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Vázquez
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/Francisco Tomás y Valiente, Nº7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Pariente
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/Francisco Tomás y Valiente, Nº7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Lorenzo
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, c/Francisco Tomás y Valiente, Nº7, Campus de Excelencia de la Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: mdolores.petit@uam.es.
authors.forename: M D
authors.initials: MD
authors.lastname: Petit-Domínguez
mesh_terms: D015374:Biosensing Techniques; D018130:Diamond; D058266:Dielectric Spectroscopy; D004583:Electrons; D005782:Gels; D019344:Lactic Acid / Q000032:analysis*; D018625:Microscopy, Atomic Force; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D053758:Nanoparticles
chemical_list: D005782:Gels; D019344:Lactic Acid; D018130:Diamond; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase
keywords: Atomic force microscopy; Diamond nanoparticle; Enzymatic biosensor; Lactate determination; Sol–gel technology