Mónica Revenga-Parra

• Autonomous University of Madrid

A novel electrochemiluminescence (ECL) immunosensor based on electrografted carbon nanodots (CND) is developed for the sensitive determination of glyphosate in soy milk and tea. Nitrogen rich CND were synthesized by microwave radiations using mild conditions and following the principles of green chemistry. l-Arginine and 3,3′-diamino-N-methyldiprop...

Graphene Oxide (GO) is considered an ideal candidate for the fabrication of hydrogen gas (H2 (g)) sensors due to its excellent capabilities for direct wiring, thanks to the presence of functional groups, which provide an opportunity to modify its chemical functionalities. In this study, we have fabricated a H2 (g) sensor based on the precise positi...

Carbon nanodots (CNDs) with enriched periphery carboxylic groups were synthesized using the low-cost starting material glucose. The obtained CNDs were assembled onto Au electrodes following one of two strategies: covalent bonding, using cystamine as a cross-linker, or by drop-casting. The immobilized CNDs were covalently modified with the phenothia...

We present the use of operando methods for the mechanistic dilucidation of an electrochemically driven structural transformation of a Ni(II) thioacetate complex. Specifically, we employed operando Raman spectroscopy and electrochemistry, along with X-ray diffraction to characterize the electrochemically induced conversion of a paddle–wheel tetrakis...

One-step approach to simultaneously reduce and modify graphene oxide (GO) using N,N’-Bis(3,4-dihydroxybenzylidene)-1,2-diaminobenzene Schiff base ligand (3,4DHS), in order to obtain functionalized reduced graphene oxide (rGO-DHS), is described. Once the novel hybrid nanomaterial was characterized by spectroscopic and electrochemical techniques, con...

Taurine and lactate are biomarkers used for the diagnosis of different pathologies. In this study, a simple analytical approach for the direct determination of taurine and lactate in tears and saliva is described. The method is based on the use of single wall carbon nanotubes screen printed electrodes modified with films derived from the electropol...

Lactic acid is a relevant analyte in the food industry, since it affects the flavor, freshness, and storage quality of several products, such as milk and dairy products, juices, or wines. It is the product of lactose or malo-lactic fermentation. In this work, we developed a lactate biosensor based on the immobilization of lactate oxidase (LOx) onto...

Two different strategies for developing new electrocatalytic platforms based on the modification of gold or carbon screen-printed electrodes with multiwall carbon nanotubes (MWCNTs) by diazonium salt click chemistry are described. The strategies proposed are compared to MWCNTs direct adsorption. The resulting platforms were characterized by scannin...

A simple strategy for covalent immobilizing DNA sequences, based on the formation of stable diazonizedconducting platforms, is described. The electrochemical reduction of 4-nitrobenzenediazonium salt ontoscreen-printed carbon electrodes (SPCE) in aqueous media gives rise to terminal grafted amino groups.The presence of primary aromatic amines allow...

Table and Figures

We report the in situ generation of aryl diazonium cations of Azure A, a redox-active phenothiazine dye, by reaction between the corresponding aromatic aminophenyl group and sodium nitrite in 0.1M HCl. The subsequent electrochemical reduction of these dye diazonium salts gives rise to conductive electrografted films onto screen-printed carbon (SPC)...

The development of a disposable electrochemical biosensor for selective Salmonella detection in presence of other pathogens is described. The device is based on thin-film gold electrodes and is fabricated employing standard microsystems technology. The method involves the immobilization of a thiolated capture probe able to hybridize with its comple...

A new electrochemical approach for an accurate quantification of DNA base pairs in genomic human DNA amplified by polymerase chain reaction (PCR) is described. The method is based on the immobilization of the sample (a thiolated DNA fragment) on the surface of a screen-printed gold electrode through the -SH group at the 5'-end and the subsequent in...

A study on optical and electrochemical properties resulting upon interaction of Schiff base ligands with gold nanoparticles is presented. The measurements of the optical absorption and fluorescence properties have provided important information about structure-properties dependence. We show that in function of the isomer structure and its attachmen...

Impedance spectroscopy (EIS) has been proposed as the transduction principle for detecting the hybridization of DNA complementary strands. The resistance offered to the electrochemical reaction acts as the working signal, allowing an unlabelled gene assay. In our experiments, atypically large DNA oligonucleotides (110 base pairs) were used to deter...

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de . Fecha de lectura: 03-07-09 Bibliogr.: p.209-226

A screening method for rapid detection of gene mutations directly in polymerase chain reaction (PCR) of genomic DNA is described. The method involves the development of a disposable screen-printed gold electrode modified with a thiolated capture probe directly obtained from denaturated PCR genomic DNA, which recognizes (by hybridization) its fully...

Selective polynucleotide recognition and detection based on a dual-stage method are described. The method involves the development of a recognition surface based on gold nanoparticles modified with a thiolated capture probe able to hybridize with its complementary sequence (target). After hybridization, this sensing surface is removed from the solu...

The preparation of DNA-sensing architectures based on gold nanoparticles (Au-NPs) in conjunction with an “in situ” prepared ruthenium complex as a new route to improve the analytical properties of genosensors is described. In the development of these architectures several strategies to obtain Au-NPs modified gold electrodes (Au-NP/Au) have been ess...

Complexes of nickel(II) with the ligand N,N′-bis(2,5-dihydroxybenzylidene)-1,2-diaminobenzene (NiII-DHS) can be electropolymerized onto glassy carbon surfaces in alkaline solution to give electroactive films strongly adhered on the electrode surface. In alkaline solution, these poly-[NiII-DHS]/GC films present the typical voltammetric response of a...

A ruthenium complex, pentaamine ruthenium [3-(2-phenanthren-9-yl-vinyl)-pyridine] (which we refer to as RuL in the text) generated in situ has been used as a sensitive and selective electrochemical indicator in DNA sensing. The complex incorporates dual functionalities with the Ru center providing a redox probe and the ligand (L) providing a fluore...

N,N'-Bis(3,4-dihydroxybenzylidene)-1,2-diaminobenzene (3,4-DHS) and N,N'-bis(2,5-dihydroxybenzylidene)-1,2-diaminobenzene (2,5-DHS) have been used as electrochemical probes in DNA sensing. These ligands, containing ortho and para quinone functional groups, respectively, as well as planar aromatic domains, are capable of binding to double stranded D...

For the first time DHsalophen tetradentate ligands, were DHsalophen denotes N,N′-bis(dihydroxybenzylidene)-1,2-diaminobenzene, have been synthesized by combination of ortho-phenylenediamine and the corresponding isomer of the dihydroxybenzaldehyde in a solvent free system. These ligands containing ortho- and para-quinone functional groups were char...