Potentiometric detection of ATP based on the transmembrane proton gradient generated by ATPase reconstituted on a gold electrode

Electrochemical Biosensors Based on Membrane-Bound Enzymes in Biomimetic Configurations

“…AFM and electrochemical measurements indicated that more reproducible and stable results were obtained when PEG was included as spacer between the fBLM and the electrode surface. This improvement was attributed to an increase of the hydrophilic boundary, allowing for more translocation of protons across the fBLM [77]. A fBLM on gold electrodes modified with 4-APh has also been used to reconstitute the multienzimatic complex I (CpI) [78], which plays a fundamental role in the production of cellular energy.…”

“…The potentiometric ATP biosensor was tested for monitoring the presence of microbial contamination. ATP extracted from Escherichia coli cultures with different cells concentration were analyzed with the biosensor obtaining an electrochemical signal proportional to the cells concentration with a time response of 5 min [77].…”

“…Although sBLMs and tBLMs have shown to be very valuable as model systems for fundamental studies of cell membrane processes [9,25,29,45,48], we think that fBLMs are more adequate for biosensor development. The presence of a water cushion in the interface between the fBLM and the electrode facilitates the insertion of transmembrane proteins in the lipid bilayer and gives higher flexibility and mobility within the biomimetic construction [77,78,82]. Moreover, the presence of an aqueous interphase facilitates charge transfer process across the membrane, which can help in coupling the biological recognition event to the electrochemical transductor [77,78].…”

“…The presence of a water cushion in the interface between the fBLM and the electrode facilitates the insertion of transmembrane proteins in the lipid bilayer and gives higher flexibility and mobility within the biomimetic construction [77,78,82]. Moreover, the presence of an aqueous interphase facilitates charge transfer process across the membrane, which can help in coupling the biological recognition event to the electrochemical transductor [77,78]. Thus, we think that there is great potential for the development of biosensors with potentiometric or impedance detection.…”

“…Adenosin triphosphate-synthase from Escherichia coli (ATPase) reconstitution in (a) fBLM (b) fBLM-polyethylene glycol (fBLM-PEG) over gold electrodes modified with a 4-APh self-assembled monolayer (SAM). Reprinted from[77] with permission from Elsevier.…”