Papers by Jean-Manuel Raimundo
Biosensors
Monitoring and detection of cyanide are of crucial interest as the latter plays versatile roles i... more Monitoring and detection of cyanide are of crucial interest as the latter plays versatile roles in many biological events, is ubiquitous in environment, and responsible for several acute poisoning and adverse health effects if ingested. We describe herein the synthesis and characterization of novel phenothiazine-based push–pull chromogenic chemosensors suitable for naked eye cyanide sensing. Indeed, specific detections were achieved for cyanide with a LOD of ca 9.12 to 4.59 µM and, interestingly, one of the new chemosensors has also revealed an unprecedented affinity for acetate with a LOD of ca 2.68 µM. Moreover, as proof of concept for practical applications, a paper test strip was prepared allowing its use for efficient qualitative naked eye cyanide sensing.
Sensors and Actuators B: Chemical, 2020
The development of ions sensors with low limit of detection and high sensitivity and selectivity ... more The development of ions sensors with low limit of detection and high sensitivity and selectivity is required in many fields of application and still remains a challenge. We report on the first dual-gated field effect transistor sensor with an engineered lipid monolayer as top gate dielectric. The sensor was designed and fabricated for the specific detection of Cu 2+ using the Di-2-picolylamine as recognition unit. The lipid monolayer was reticulated to achieve high mechanical and dielectric stability over device operation. The resulting sensor exhibits exceptional performances with a limit of detection at 10 femtomolar, with a linear dependency over 10 decades and a super-Nernstian sensitivity of ~100 mV/decade. We also show that the lipid layer forms a good barrier to ions trapping, hence providing a high stability of the sensor over measurements.
Synthesis, 2006
The reagent, tetrabutylammonium difluorotriphenylstannate, was easily prepared on a multigram sca... more The reagent, tetrabutylammonium difluorotriphenylstannate, was easily prepared on a multigram scale (~100 g). Several of its applications are presented, either as a soluble, thermally stable and anhydrous nucleophilic fluorinating agent or as a synthetic equivalent to PhMgX or PhLi species under aqueous and aerobic conditions. The proposed methodologies emphasize the concept of hypercoordination and its usefulness for improving selectivity, reactivity and shelf-stability of reagents.
International Journal of Molecular Sciences, 2022
Prosthetic implants are widely used in dentistry and orthopedics and, as a result, infections can... more Prosthetic implants are widely used in dentistry and orthopedics and, as a result, infections can occur which cause their removal. Therefore, it is essential to propose methods of eradicating the bacteria that remain on the prosthesis during treatment. For this purpose, it is necessary to develop surfaces whose antibacterial activity can be controlled. Herein, we designed innovative and smart phosphonium self-assembled monolayer (SAM) interfaces that can be electrically activated on demand for controlling bacterial contaminations on solid surfaces. Upon electroactivation with a low potential (0.2 V for 60 min., conditions determined through a DOE), a successful stamping out of Gram-positive and Gram-negative bacterial strains was obtained with SAM-modified titanium surfaces, effectively killing 95% of Staphylococcus aureus and 90% Klebsiellapneumoniae. More importantly, no toxicity towards eukaryotic cells was observed which further enhances the biocompatible character of these nove...
Análise e projeto de estrutura de contenção em ruptura de talude por erosão: estudo de caso Os pr... more Análise e projeto de estrutura de contenção em ruptura de talude por erosão: estudo de caso Os processos erosivos fundamentam-se essencialmente na desagregação, transporte e deposição do solo, com a ação dos agentes erosivos água, ventos e ou gelo. Sabe-se que o solo tem uma capacidade de suportar esforços, porém, se suas características forem alteradas, a capacidade de carga sofrerá alterações, podendo torna-se um solo frágil, um fator com a característica de diminuir a resistência do solo é a erosão. Diante do exposto o artigo propõe analisar e dimensionar uma estrutura de gabião para conter o processo erosivo do solo situado no município de Porto Nacional, nas proximidades do ribeirão São João, na Av. Padre Luso. Destaca-se que esta ruptura está à menos de um metro de distância de uma edificação e caso persista irá atingir mais cinco edificações circunvizinhas. Neste estudo foram realizados ensaios de caracterização do solo. Na análise de estabilidade da estrutura de gabião proposta para contenção do talude, foram verificados os critérios de deslizamento, tombamento e capacidade de carga conforme a NBR 11682/1991. Além disso, também foi feita a análise global do sistema talude/muro. Verificou-se que a estrutura proposta atende os requisitos técnicos de segurança. Palavras-chave: Erosão; Estruturas de Contenção; Estabilidade de taludes. Analysis and design of containment structure in eruption talud rupture: case study The erosive processes are essentially based on the disintegration, transport and deposition of the soil, with the action of erosive agent's water, winds and or ice. It is known that the soil has a capacity to withstand stresses, however, if its characteristics are altered, the load capacity will undergo changes, being able to become a fragile soil, a factor with the characteristic of diminishing soil resistance is erosion. In view of the above, the article proposes to analyze and size a gabion structure to contain the soil erosion process located in the municipality of Porto Nacional, in the vicinity of the São João stream, on Padre Luso Avenue. It should be noted that this rupture is less than one meter away from a building and if it persists it will reach another five surrounding buildings. In this study, soil characterization tests were carried out. In the stability analysis of the gabion structure proposed for containment of the slope, the sliding, tipping and load capacity criteria were verified according to NBR 11682/1991. In addition, the overall analysis of the slope / wall system was also performed. It was found that the proposed structure meets the technical safety requirements.
Molecular self-assembly is one of the most promising strategy for giving surface specific propert... more Molecular self-assembly is one of the most promising strategy for giving surface specific properties with a nanoscale control. An important field of application of self-assembled monolayers (SAMs) is the so-called "molecular electronics" within which self-assembly is a very powerful way to obtain the organization at large surface scale of molecules showing particular electro-optical properties. After the principle of SAM preparation, the motivation of developing SAMs of small organic molecules will be briefly illustrated by some examples of controlling the molecular structuration on silicon surfaces. How organization at the molecular scale acts on electro-optical properties of molecular chromophores will then be discussed focusing on two examples: a structure-electrical properties relationship probed by STM and the SAM of a novel push-pull thiophene-based chromophore . For the latter, dense SAM formation of such non-charged chromophore is for the first time clearly demonst...
Applied Surface Science, 2018
The surface state of Mn 5 Ge 3 exposed to air and common colvents, is analyzed by XPS. The surfac... more The surface state of Mn 5 Ge 3 exposed to air and common colvents, is analyzed by XPS. The surface free energy of Mn 5 Ge 3 is calculated with the OWRK method. The grafting of Mn 5 Ge 3 films by octane-and perfluorodecane-thiol SAMs is proposed.
Analytical chemistry, Jan 14, 2016
We report herein the fabrication of novel microarrays based on air-stable functional lipid monola... more We report herein the fabrication of novel microarrays based on air-stable functional lipid monolayers over silicon using a combination of e-beam lithography and lift-off. We demonstrate these microarrays can be use as ultra-sensitive platform for Kelvin probe force microscopy in sensing experiments. Specificity of the detection is given by the functional group grafted at the lipid head-group. The arrays developed for the detection of ferric ions, Fe(3+), using a γ-pyrone derivative chelator, demonstrate sub-picomolar limit of detection with high specificity. In addition, the technique takes advantage of the structure of the array with the silicon areas playing the role of reference for the measurement, and we determine critical pattern dimensions below which the probe size/shape impacts the measured results.
Physics Education, 2016
Semiconductors materials are at the basis of electronics. Most electronic devices are made of sem... more Semiconductors materials are at the basis of electronics. Most electronic devices are made of semiconductors. The operation of these components is well described by quantum physics which is a little mysterious to students. One of the intrinsic parameters of semiconductors is their bandgap energy Eg. In the case of light-emitting diodes (LEDs) Eg fixes the colour of the light emitted by the diodes. We propose in this article a lab work allowing a comparison of Eg of a green LED obtained by both electrical and optical measurements. The two slightly different results can be explained by the theoritical knowledges of the students on solid physics and electronic devices internal architecture.
Tetrahedron, 2016
Thiophene-based molecular semiconductors are of high interest in the development of optoelectroni... more Thiophene-based molecular semiconductors are of high interest in the development of optoelectronics devices and are extensively used. So far, structural variations have been widely performed on linear molecular push-pull in order to optimize their photophysical properties while 2D systems are quite limited. We report herein the synthesis of four new chromophores based on bithiophene core end-capped with dibutylaminostyryl groups and functionalized on the 3,3' position with different electron withdrawing groups. Optical and electrochemical characterizations have been performed as well as theoretical calculations that corroborate the experimental data.
RSC Adv., 2015
A series of new alkoxy-ferrocene methacrylates was polymerized by the raft process leading to red... more A series of new alkoxy-ferrocene methacrylates was polymerized by the raft process leading to redox polymers with low Tg values.
Talanta, 2015
In order to highlight the importance of the complex stoichiometry during ion imprinted polymer (I... more In order to highlight the importance of the complex stoichiometry during ion imprinted polymer (IIP) synthesis, we investigated the effect of the complex structure on IIPs selectivity by adjusting the complex stoichiometry before polymerization. 2-(aminomethyl)pyridine monomer (amp) was chosen as a functionalized ligand for nickel(II) ions and a polymerizable vinylbenzyl derivative (Vbamp) was prepared. Complex formation was studied by varying the nickel/Vbamp ratio and recording absorption spectra of the complexes at the polymerization conditions. Using a least-squares minimization scheme, the complex species distribution was successfully established. From these results, it was possible to choose the metal/ligand stoichiometry in the complex (1:1; 1:2 or 1:3) by adjusting the initial metal/ligand ratio. IIPs were then prepared by inverse suspension copolymerization of Vbamp with ethyleneglycol dimethacrylate (EDMA). Highly porous particles with good nickel binding capacity and good...
Journal of Physical Chemistry C, 2008
Journal of Materials Chemistry B, 2013
An innovative MOS-type field effect transistor was developed for the electrical detection of ferr... more An innovative MOS-type field effect transistor was developed for the electrical detection of ferric ions. The sensing assays clearly show a specific detection with a gate-source voltage shift of up to 200 mV and a wide linear detection range (5 × 10-14 to 5 × 10-5 M) associated with good stability, selectivity and reproducibility.
Macromolecular Research, 2009
Advanced Materials, 2013
An ion-sensitive electrolyte-gated organic field-effect transistor for selective and reversible d... more An ion-sensitive electrolyte-gated organic field-effect transistor for selective and reversible detection of sodium (Na(+) ) down to 10(-6) M is presented. The inherent low voltage - high current operation of these transistors in combination with a state-of-the-art ion-selective membrane proves to be a novel, versatile modular sensor platform.
The surface state of Mn 5 Ge 3 exposed to air and common colvents, is analyzed by XPS. The surfac... more The surface state of Mn 5 Ge 3 exposed to air and common colvents, is analyzed by XPS. The surface free energy of Mn 5 Ge 3 is calculated with the OWRK method. The grafting of Mn 5 Ge 3 films by octane-and perfluorodecane-thiol SAMs is proposed.
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Papers by Jean-Manuel Raimundo