Highly sensitive olfactory biosensors for the detection of volatile organic compounds by surface plasmon resonance imaging

International audience; Nowadays, monitoring of volatile organic compounds (VOCs) is very important in various domains. In this work, we aimed to develop sensitive olfactory biosensors using odorant binding proteins (OBPs) as sensing materials. Three rat OBP3 derivatives with customized binding properties were designed and immobilized on the same chip for the detection of VOCs in solution by surface plasmon resonance imaging (SPRi). We demonstrated that the proteins kept their binding properties after the immobilization under optimized conditions. The obtained olfactory biosensors exhibited very low limits of detection in both concentration (200pM of beta-ionone) and in molecular weight of …

Development of novel biomimetic sensor materials for optoelectronic nose applications

International audience

Electrochemistry of methylene blue at an alkanethiol modified electrode

International audience; Gold surfaces were derivatized with decanethiol. The electrochemistry of methylene blue at these modified electrodes was investigated in function of the gold cleaning process and compared with the results obtained at a bare gold electrode. Cyclic voltammetry at low methylene blue concentrations (c(MB) <= 16 mu M) yielded surface behavior data. The properties of the film vary with the electrode pretreatment. Without electrochemical cleaning step, the standard potential at a gold electrode modified with 1-decanethiol is nearly the same as on a bare gold electrode. On the other hand, when the electrode is electrochemically cleaned before adsorption of the alkanethiols, …

Electrochemical detection of the 2-isobutyl-3-methoxypyrazine model odorant based on odorant-binding proteins: The proof of concept

Abstract We developed an electrochemical assay for the detection of odorant molecules based on a rat odorant-binding protein (rOBP3). We demonstrated that rOBP3 cavity binds 2-methyl-1,4-naphtoquinone (MNQ), an electrochemical probe, as depicted from the decrease of its electrochemical signal, and deduced the dissociation constant, Kd MNQ  = 0.5(± 0.2) μM. The amount of MNQ displaced from rOBP3 by 2-isobutyl-3-methoxypyrazine (IBMP), a model odorant molecule, was measured using square-wave voltammetry. The release of MNQ by competition led to an increase of the electrochemical response. In addition, this method allowed determination of the dissociation constant of rOBP3 for IBMP, Kd IBMP  =…

Odorant-binding protein-based optoelectronic tongue and nose for sensing volatile organic compounds

International audience; We developed an array of odorant-binding protein mutants with various binding properties. The same design is suitable for the detection and identification of volatile organic compounds (VOCs) both in the liquid phase and in the gas phase by surface plasmon resonance imaging. The obtained optoelectronic tongue is highly selective at low concentrations of VOCs with a low detection limit, but a narrow linear range. In comparison, the optoelectronic nose gives a much higher signal to noise ratio, but the discrimination of VOCs from different chemical classes requires kinetic data to get rid of non-specific signals. This work shows that these optoelectronic tongue and nos…

De l’ingénierie de protéines de liaison aux odorants à la détection électrochimique de molécules volatiles vers la conception de biocapteurs et nez électroniques

The detection of odorant molecules has become an important challenge in different research area, such as the food industry, medical diagnostics and homeland security. Indeed, the thousands of odorants in our environment provide information on their chemical nature or their concentration. Human olfactory system is capable of discriminating thousands of different molecules thanks to biochemical mechanisms involving multiple protein receptor partners and a combinatorial coding. These biomolecules that include olfactory receptors and odorant-binding proteins (OBP) represent an interesting source of detectors for the design of biosensors. OBPs are small soluble proteins present in nasal mucus at…

Development of a novel olfactory biosensor based on surface plasmon resonance imaging

Monitoring volatile organic compounds (VOCs) is a key issue in many industrial domains, from food industry to public safety. Here, we propose a biomimetic alternative to traditional analytical methods such as gas chromatography and mass spectroscopy. Novel olfactory biosensor was developed using surface plasmon resonance imaging (SPRi) and odorant binding proteins (OBPs). OBPs are robust and can reversibly bind VOCs with a micromolar affinity. Herein, three mutant OBPs with tuned binding properties were immobilized on a chip in a microarray format to detect VOCs in liquid. We demonstrated that SPRi was efficient for the analysis of VOCs. The olfactory biosensor exhibited a low limit of dete…

Development of olfactory biosensors for the detection of small molecules by SPRi

National audience

Odorant-binding protein engineering: impact on binding properties

Surface plasmon resonance imaging for sensing volatile organic compounds: Biomimetic olfactory biosensors and optoelectronic nose

National audience; Nowadays, there is a growing demand for the analysis of volatile organic compounds (VOCs) in various domains, including environment, quality control, and medical diagnostics. Traditional analytical methods, though accurate and reliable, require expensive equipment and are often time-consuming and laborious. On the other side, food & fragrance industries employ human sensory panels to evaluate the quality of an odour. However, panellists are expensive to train and employ and they can give biased results. To bridge the gap, we developed different sensor systems inspired by the human nose. Here, a biomimetic olfactory biosensor based on key-and-lock principle was designed us…

A biometic olfactory based biosensor combining electrochemistry and odorant-binding

A biometic olfactory based biosensor combining electrochemistry and odorant-binding. Food Factory 2012