Highly sensitive gold-overoxidized polypyrrole nanocomposite immunosensor for antitransglutaminase antibody

Abstract

Patients with coeliac disease, a gluten intolerance autoimmune disorder, have elevated levels of antitransglutaminase antibody in their human sera. In this study, an immunosensor for the electrochemical determination of antitransglutaminase antibody was constructed. The immunosensor architecture was based on the electrostatic deposition of transglutaminase antigen on a glassy carbon electrode modified with electrosynthetic overoxidized polypyrrole and gold nanoparticles and capped the transglutaminase layer with bovine serum albumin. As a result, good surface coverage of the gold nanoparticles (~100 nm) was achieved across the overoxidized polypyrrole film. Electrochemical impedance spectroscopy parameters of the gold nanoparticle–overoxidized polypyrrole electrode include time constant, exchange current density, and heterogeneous rate constant. The impedimetric immunosensor exhibited a charge transfer resistance-dependent linear range with a correlation coefficient value of 0.98 and a dynamic linear range of 10−6–10−4 mg mL−1. The synergistic effect of the gold nanoparticles on the overoxidized polypyrrole formed the electronic insulator platform as a selective accumulator for the analytes surrounding the nanoelectrode. This biosensor characteristic enabled detection of antitransglutaminase antibodies at very low concentrations without the aid of a secondary label.

The Alphabet of Nanostructured Polypyrrole

“…An elegant immunosensor for the detection of anti-transglutaminase antibodies was constructed utilizing an overoxidized polypyrrole matrix [161]. A transglutaminase (tTG)specific antibody represents a specific biological marker for coeliac disease.…”

Biosensors for Non-Invasive Detection of Celiac Disease Biomarkers in Body Fluids

“…Labeling increased the sensitivity of the sensor to the level of on-chip ELISA. A sensitive label-free impedimetric TGA immunosensor was developed by West et al [ 36 ] based on overoxidized polypyrrole (OPPy) as substrate for binding capture tTG protein. The working electrode of the sensor was constructed by electrodepositing OPPy and AuNPs on glassy carbon electrode (GCE) and drop-coating tTG onto the AuNP/OPPy film.…”

Developing Biosensors in Developing Countries: South Africa as a Case Study

“…Examination of the biosensor transducer types in Table 2 [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ] reveals an overwhelming amount of research originating from South Africa has been focused on electrochemical (amperometric, impedimetric, potentiometric and voltammetric) configurations of biosensors, with only a few publications found investigating colourimetric/photometric bases for signal generation. This is, itself, due to the many commonly reported beneficial properties of electroanalysis over other transducers—e.g., low fabrication-cost, consistency of fabrication, high degree of alloweable automation, ability to derive multiple signals from a single analytical device (signal multiplexing), lower anal...…”

“…The amperometric detection of the human thyroid hormone (+)-3,3′,5-Triiodo-L-thyronine (L-T 3 ), and discrimination against the pro-hormone L-T 4 , was improved through the selective retention at carbon paste electrodes using anti-L-T 3 antisera [ 32 ]. Similarly, inclusion of biological antigens as biorecognition agents of sensors allowed for the diagnosis of gluten intolerance [ 34 ], through the detection of antibodies produced to resist these disease states.…”