Functional Infectious Nanoparticle Detector: Finding Viruses by Detecting Their Host Entry Functions Using Organic Bioelectronic Devices

Abstract

Emerging viruses will continue to be a threat to human health and wellbeing into the foreseeable future. The COVID-19 pandemic revealed the necessity for rapid viral sensing and inhibitor screening in mitigating viral spread and impact. Here, we present a platform that uses a label-free electronic readout as well as a dual capability of optical (fluorescence) readout to sense the ability of a virus to bind and fuse with a host cell membrane, thereby sensing viral entry. This approach introduces a hitherto unseen level of specificity by distinguishing fusion-competent viruses from fusion-incompetent viruses. The ability to discern between competent and incompetent viruses means that this device could also be used for applications beyond detection, such as screening antiviral compounds for their ability to block virus entry mechanisms. Using optical means, we first demonstrate the ability to recapitulate the entry processes of influenza virus using a biomembrane containing the viral receptor that has been functionalized on a transparent organic bioelectronic device. Next, we detect virus membrane fusion, using the same, label-free devices. Using both reconstituted and native cell membranes as materials to functionalize organic bioelectronic devices, configured as electrodes and transistors, we measure changes in membrane properties when virus fusion is triggered by a pH drop, inducing hemagglutinin to undergo a conformational change that leads to membrane fusion.

Supported Lipid Bilayer Platform for Characterizing the Membrane-Disruptive Behaviors of Triton X-100 and Potential Detergent Replacements

“…Future improvements to the SLB platform might include using a membrane composition that is more representative of viral envelopes as well as exploring other types of model membrane platforms such as intact liposome adlayers that better mimic the membrane curvature of small, enveloped virus particles as opposed to the planar SLB configuration. Considering that viral envelopes also contain membrane-associated proteins, reconstitution of viral membrane extracts on sensor surfaces might also be considered (see, e.g., recent works involving other types of biological membranes [ 43 , 44 ]) and could be useful in terms of studying detergent interactions with a more complex milieu of lipids and proteins. In addition, while the QCM-D technique provides a useful label-free measurement approach for quantitative evaluation of detergent-mediated membrane disruption, deeper biophysical understanding of the corresponding interactions from a fundamental perspective could be obtained by utilizing additional techniques such as time-lapse fluorescence microscopy in conjunction with fluorescently labeled SLBs.…”

Towards organic electronics that learn at the body-machine interface: A materials journey

“…In biosensing applications, for detecting subtle changes in a highly dynamic environment, the above-discussed OECT layout has been complemented by EIS measurements which account for capacitive changes at each interface of the device. [2,31] For instance, a gate electrode functionalized with bio-recognition elements that can selectively interact with biomarkers of interest, can be modelled as a polarizable electrode with a known resistance and capacitance. The entire device, hence, completes a typical Randles' circuit with the gate and the channel in-series via the electrolyte.…”

“…Such changes are then accurately detected using EIS, are manifested in the device's V T as a function of the analyte concentration, and are amplified through the changes in the source-drain current. [2,[31][32][33] The sensitivity can be tuned by adjusting the ratio of capacitive contributions of different components of the model circuit.…”

Organic Bioelectronics for In Vitro Systems

“…This method can therefore readily serve as an alternative to patch clamp whole cell experiments. (Figure ) , Very recently, this technology was implemented for fundamental understanding of membrane events governed by infection processes including virus–membrane interactions, as well as toxin binding …”