Voltage-sensitive ion-channel-coupled receptors (ICCRs) are integrated with budded baculovirus particles (BBVs) for the amplification of bioelectronic nose signals via external voltage stimulation. Here, BBVs are employed as stable and uniform nanoscaffolds to introduce ICCRs into field-effect transistor devices, providing a direct alternative to conventional nanovesicle-based membrane platforms. ICCRs composed of human olfactory receptors (hOR2AG1) and potassium ion channels (Kir6.2) are transfected into BBV membranes, and then, the BBVs are immobilized on the channel region of a carbon nanotube field-effect transistor (CNT-FET). In this hybrid device, voltage-dependent ion channel gating behavior can be triggered by the stimulation of liquid gate voltages ( V LG ) to BBV membranes. The opening of ion channels leads to local fluctuations in junction potential between the BBV membrane and the CNT channel, which can be observed by changes in the channel conductance. Importantly, receptor-ligand binding activities of ICCR in BBV membranes can be modulated by applying different V LG values. The EC 50 values for the receptor-ligand binding are estimated as 204 pM , 70.8 fM , and 1.4 fM for V LG of −80 mV , −120 mV, and −180 mV , respectively. This voltage-dependent modulation originates from changes in the BBV membrane potential, which alter the receptor binding affinity and reduce the ligand concentration required to induce a half-maximal sensor response into femtomolar ranges. Thus, our strategy can be utilized to achieve tunable signal amplification capabilities of bioelectronic nose device. A bioelectronic nose is constructed through a combination of carbon nanotube field-effect transistors and ion-channel-coupled receptors (ICCRs) integrated with budded baculovirus particles. Using this hybrid device, olfactory receptor–ligand binding affinities within virus membranes can be modulated by varying liquid gate voltages. Such voltage-dependent activities of ICCRs allow ones to achieve tunable signal amplification capabilities. • Ion-channel-coupled receptors in baculovirus particles are integrated into a CNT-FET bioelectronic nose. • Liquid gate voltages trigger ion channel gating in the baculovirus membrane. • Voltage-induced modulation of receptor–ligand affinity enables attomolar sensitivity. • This hybrid sensor can be utilized to achieve tunable signal amplification capabilities.
Park et al. (Fri,) studied this question.