Using Cell Membranes as Recognition Layers to Construct Ultrasensitive and Selective Bioelectronic Affinity Sensors

Abstract

Conventional sandwich immunosensors rely on antibody recognition layers to selectively capture and detect target antigen analytes. However, the fabrication of these traditional affinity sensors is typically associated with lengthy and multistep surface modifications of electrodes and faces the challenge of nonspecific adsorption from complex sample matrices. Here, we report on a unique design of bioelectronic affinity sensors by using natural cell membranes as recognition layers for protein detection and prevention of biofouling. Specifically, we employ the human macrophage (MΦ) membrane together with the human red blood cell (RBC) membrane to coat electrochemical transducers through a one-step process. The natural protein receptors on the MΦ membrane are used to capture target antigens, while the RBC membrane effectively prevents nonspecific surface binding. In an attempt to detect tumor necrosis factor alpha (TNF-α) cytokine using the bioelectronic affinity sensor, it demonstrates a remarkable limit of detection of 150 pM. This new sensor design integrates natural cell membranes and electronic transduction, which offers synergistic functionalities toward a broad range of biosensing applications.

Conductive Antifouling Sensing Coating: A Bionic Design Inspired by Natural Cell Membrane

“…Based on this antifouling concept of cell membranes regulating the adsorption of biological components, [54] various cell membrane coating technologies have been successfully created, including coatings on sensing platforms. [48,49,55] Cell membranes provided antifouling protection owing to the fact that they exhibited an abundance of zwitterionic headgroups in phospholipid bilayers and the steric hindrance of glycoproteins. [48,49,55,56] Thus, in our study, we applied cell membranes to the sensing interface to perform antifouling owing to the hydrophilic protective layer of glycoprotein and phospholipids.…”

“…[48,49,55] Cell membranes provided antifouling protection owing to the fact that they exhibited an abundance of zwitterionic headgroups in phospholipid bilayers and the steric hindrance of glycoproteins. [48,49,55,56] Thus, in our study, we applied cell membranes to the sensing interface to perform antifouling owing to the hydrophilic protective layer of glycoprotein and phospholipids. As illustrated in Figure 1E-G, the cell membranes layer could prevent protein adsorption, and the water contact angle of the cell membranes was better than that of the bare and BSA coatings, demonstrating the good hydrophilicity of the cell membranes.…”

Electrochemical Affinity Biosensors: Pervasive Devices with Exciting Alliances and Horizons Ahead

“…Furthermore, the use of nature-inspired bioreceptors produced by modern technologies (HaloTag, Phage display, and directed mutation) has been crucial in recent years for electrochemical affinity biosensing to (i) explore new biorecognition elements independently of their commercial availability; (ii) discover and test the clinical potential of new biomarkers and molecular signatures; and (iii) develop competitive bioelectroanalytical tools helping the implementation of precision medicine, therapy, and nutrition. These nature-inspired receptors include, among others, natural cell membranes, molecular switches (DNAs, aptamers or peptides, dually modified with a linker for immobilization on the electrode substrate, and a redox-active reporter that reversibly change between at least two conformations in response to the specific binding of a molecular target), inverted molecular pendulums (double-stranded DNAs containing at its distal end an antibody that recognizes the target analyte), − peptides, protein, viral antigens, and proteoforms (all of the different molecular forms in which the protein product of a single gene can be found).…”

Enzymatic Galvanic Redox Potentiometry for In Vivo Biosensing

“…Past decades have witnessed great advances in in vivo electrochemical sensing technology for monitoring neurochemical events underlying brain functions. − As a result, a variety of brain tissue-implantable sensors based on electrochemical principles and methods have been developed, most of which are based on electrolytic mechanism requiring external power supply to polarize electrodes to drive interfacial reactions and generate currents. − However, externally applied working potential and consequently generated current flow may influence neuronal activities, particularly when the applied potential is high or the current flow is big. − In addition, the sensitivity of the sensors loses significantly owing to electrode fouling through nonspecific adsorption of proteins when the sensors are implanted into brain tissues. − Unlike the electrochemical methods based on electrolytic mechanism, we recently found that potentiometry with open-circuit voltage ( E OC ) spontaneously generated with galvanic mechanism as the output signal (termed as galvanic redox potentiometry, GRP) is particularly useful for the in vivo analysis of redox neurochemicals. − This is because the GRP sensors feature near-zero current with negligible reactant consumption and product generation during the sensing processes and are thus more biocompatible with minimal effect on neurons and stable for in vivo analysis with uncompromised sensitivity after electrode implantation, even with the presence of electrode fouling.…”