Impedance Biosensing atop MoS₂ Thin Films with Mo−S Bond Formation to Antibody Fragments Created by Disulphide Bond Reduction

Abstract

Immobilization of antibody fragments to 3‐phenoxybenzoic acid (3‐PBA), which are created by disulphide bond (S−S) reduction with tris (2‐carboxyethyl) phosphine (TCEP), is reported atop MoS2 and Cu‐doped MoS2 thin films. MoS2 and Cu‐doped MoS2 thin films are electrodeposited using previously reported methods and tested for their ability to immobilize antibody fragments, before and after annealing in Ar at 500 °C for 3 h. This annealing procedure removes excess sulphur in the as‐deposited films, and creates coordinatively unsaturated Mo sites that are highly reactive towards sulphur, as previously reported for MoS2 hydrodesulphurization catalysts. As demonstrated by electrochemical impedance spectroscopy (EIS) measurements, both annealed MoS2 and Cu‐doped MoS2 thin films adsorb antibody fragments through Mo−S bond formation, unlike the as‐deposited films. Impedance detection of 3‐PBA is reported utilizing antibody fragments bound to both materials, with a sensitivity of 2.7×108 Ω cm2 M−1 and a detection limit of 2.5×10−6 M atop MoS2, and a sensitivity of 5.9×108 Ω cm2 M−1 and a detection limit of 3.8×10−6 M atop Cu‐doped MoS2. The rms surface roughness obtained by atomic force microscopy (AFM) measurements atop annealed MoS2 and Cu‐doped MoS2 ranges from 60–140 nm, so the methods described herein are not limited to ultra‐smooth substrates.

Two-dimensional material-based virus detection

“…The second detection category based on the antibody-antigen specific recognition interaction offers another convenient way for detecting viruses with high sensitivity and selectivity, which enables the more extensive applications of this technique in recent years [94][95][96][97][98]. As shown in Figure 4, a label-free electrochemical immunosensor was developed by integrating rGO into a novel microfluidic chip to detect influenza virus, H1N1.…”

Laser‐Fabricated 2D Molybdenum Disulfide Electronic Sensor Arrays for Rapid, Low‐Cost, Ultrasensitive Detection of Influenza A and SARS‐Cov‐2

“…[ 11 ] More recently, reports of prostate‐specific antigen sensing via “chemically reduced” PSA antibodies bound to thick (1 µm) MoS 2 transducers through disulfide linkages between the MoS 2 nanosheets and the modified antibodies with exposed sulfhydryl (SH) groups. [ 12 ]…”

“…[11] More recently, reports of prostate-specific antigen sensing via "chemically reduced" PSA antibodies bound to thick (1 µm) MoS 2 transducers through disulfide linkages between the MoS 2 nanosheets and the modified antibodies with exposed sulfhydryl (SH) groups. [12] Utilization of the dual specific binding attributes of antibody fragments to transducer and antigen is an attractive means to achieve sensor selectivity. In the case of influenza A (Figure 1d), hemagglutinin (HA) and neuraminidase are glycoproteins known to interact with receptor binding domains of antibodies [13] as shown in Figure 1e.…”

Target‐stimulated DNAzyme Concatamers Released from Aptasensor for Highly Sensitive and Specific Detection of Progesterone

“…Sensitive and specific determination of endocrine system disorder‐related biomarkers is essential in the modern medicine, biological, treatment and clinic diagnosis . Typically, the methodology can be performed using certain affinity ligands comprising the corresponding aptamers and antibodies that specifically interact with biomolecules and thus initiate a target‐responsive signal transduction cascade . For the successful exploitation of target‐induced sensor system, design of signal‐mediated strategy is of great attention .…”