Grafting odorant binding proteins on diamond bio-MEMS

Abstract

Odorant binding proteins (OBPs) are small soluble proteins found in olfactory systems that are capable of binding several types of odorant molecules. Cantilevers based on polycrystalline diamond surfaces are very promising as chemical transducers. Here two methods were investigated for chemically grafting porcine OBPs on polycrystalline diamond surfaces for biosensor development. The first approach resulted in random orientation of the immobilized proteins over the surface. The second approach based on complexing a histidine-tag located on the protein with nickel allowed control of the proteins' orientation. Evidence confirming protein grafting was obtained using electrochemical impedance spectroscopy, fluorescence imaging and X-ray photoelectron spectroscopy. The chemical sensing performances of these OBP modified transducers were assessed. The second grafting method led to typically 20% more sensitive sensors, as a result of better access of ligands to the proteins active sites and also perhaps a better yield of protein immobilization. This new grafting method appears to be highly promising for further investigation of the ligand binding properties of OBPs in general and for the development of arrays of non-specific biosensors for artificial olfaction applications.

Olfactory biosensor for insect semiochemicals analysis by impedance sensing of odorant-binding proteins on interdigitated electrodes

“…Compared with other biosensors that were based on OBPs to detect semiochemicals, such as surface acoustic wave (SAW), quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and cantilever sensors (Pietrantonio et al, 2013(Pietrantonio et al, , 2014Sankaran et al, 2011;Vidic et al, 2008;Manai et al, 2014), the biosensor in our study had its own superiorities. The performances of different sensors were summarized in Table 1.…”

Smell Sensors Based on Odorant Binding Proteins

“…Isoamy acetate, β-ionone, Benzaldehyde [14] Rat OBP-1F Isoamyl acetate [5] Porcine OBP (pOBP) Ethanol [19] Cantilever Porcine OBPs 2-isobutyl-3-methoxypyrazine [13] Surface acoustic wave (SAW)…”

Towards bionic noses

“…Cantilever sensors based on polycrystalline diamond surfaces with pig OBP (Manai et al, 2014). A new bio-sensing platform based on major urinary proteins (MUPs) from the mouse as chemical recognition elements was demonstrated (Scorsone et al, 2016) using SAW devices coated with diamond enabling covalent attachment of the proteins.…”