Aptamer-antibody sandwich assay for cytochrome c employing an MWCNT platform and electrochemical impedance

Ocaña, Cristina; Lukic, Sonja; Valle, Manel del

doi:10.1007/s00604-015-1540-6

Cited by 34 publications

(5 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar strategies were also employed by replacing antibodies with aptamers. − Ocaña et al reported a label-free impedimetric aptasensor for the recognition of cyt c at picomolar concentration levels based on an epoxy–graphite composite electrode. When the protein interacted with the immobilized aptamer on the aptasensor, it was detected by electrochemical impedance spectroscopy (EIS).…”

Section: Technological Applications Of Cytochrome Cmentioning

confidence: 99%

Multifunctional Cytochrome c: Learning New Tricks from an Old Dog

et al. 2017

View full text Add to dashboard Cite

Cytochrome c (cyt c) is a small soluble heme protein characterized by a relatively flexible structure, particularly in the ferric form, such that it is able to sample a broad conformational space. Depending on the specific conditions, interactions, and cellular localization, different conformations may be stabilized, which differ in structure, redox properties, binding affinities, and enzymatic activity. The primary function is electron shuttling in oxidative phosphorylation, and is exerted by the so-called native cyt c in the intermembrane mitochondrial space of healthy cells. Under pro-apoptotic conditions, however, cyt c gains cardiolipin peroxidase activity, translocates into the cytosol to engage in the intrinsic apoptotic pathway, and enters the nucleus where it impedes nucleosome assembly. Other reported functions include cytosolic redox sensing and involvement in the mitochondrial oxidative folding machinery. Moreover, post-translational modifications such as nitration, phosphorylation, and sulfoxidation of specific amino acids induce alternative conformations with differential properties, at least in vitro. Similar structural and functional alterations are elicited by biologically significant electric fields and by naturally occurring mutations of human cyt c that, along with mutations at the level of the maturation system, are associated with specific diseases. Here, we summarize current knowledge and recent advances in understanding the different structural, dynamic, and thermodynamic factors that regulate the primary electron transfer function, as well as alternative functions and conformations of cyt c. Finally, we present recent technological applications of this moonlighting protein.

show abstract

Section: Technological Applications Of Cytochrome Cmentioning

confidence: 99%

Multifunctional Cytochrome c: Learning New Tricks from an Old Dog

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Although EIS sandwich immunoassays have previously been reported that utilize Au nanoparticles, horseradish peroxidase, and/or cytochrome c for the signal amplification , none of these studies directly compare the sensitivity obtained for direct and sandwich assays. Due to the significant difference in size between the M13 bacteriophage (MW∼16.3 MDa) and 3‐PBA (MW=214.2),one expects a much improved sensitivity for the 3‐PBA sandwich EIS immunoassay relative to the direct EIS immunoassays, and a reduction of 70× is observed for the detection limit.…”

Section: Resultsmentioning

confidence: 99%

Impedance Detection of 3‐Phenoxybenzoic Acid with a Noncompetitive Two‐site Phage Anti‐immunocomplex Assay

et al. 2018

View full text Add to dashboard Cite

Both direct and non‐competitive two‐site (sandwich) immunoassays are reported for 3‐phenoxybenzoic acid (3‐PBA) utilizing signal transduction by electrochemical impedance spectroscopy (EIS), and the sandwich immunoassay reduces the detection limit for this small molecule analyte by ∼70×. The direct EIS immunoassay utilizes a polyclonal antibody to 3PBA for biomolecular recognition, while the sandwich EIS immunoassay utilizes in addition a previously reported antiimmunocomplex M13 bacteriophage clone. For both immunoassays, the polyclonal antibody film is immobilized atop an Au electrode by amide bond formation. The direct EIS immunoassay exhibits a 3‐PBA sensitivity of 5.4×104 kΩ cm2 M1, and a detection limit of 2.5×10−4 M (54 μg/ml), while the sandwich EIS immunoassay exhibits a 3PBA sensitivity of 4.2×106 kΩ cm2 M−1, and a detection limit of 3.4×10−6 M (0.74 μg/ml). For the sandwich EIS immunoassay, a constant excess (80×109 PFU/ml) of bacteriophage is maintained during all experiments. This is the first report of a bacteriophage‐assisted sandwich EIS assay.

show abstract

“…Both gold- and carbon-based electrodes are commonly employed as substrates for developing electrochemical aptasensors for food safety monitoring [ 42 ]. Different approaches have been reported for the immobilization of aptamers, such as physical adsorption [ 95 , 96 ], self-assembly [ 24 , 97 , 98 ], entrapment in polymer films [ 99 ], and covalent grafting at functionalized surfaces [ 61 , 100 , 101 ] ( Scheme 1 ).…”

Section: Strategies In Electrochemical Aptasensor Design: Aptamer Immobilization and Electrochemical Signal Generationmentioning

confidence: 99%

The Role of Aryldiazonium Chemistry in Designing Electrochemical Aptasensors for the Detection of Food Contaminants

Raicopol

Pilan

2021

Materials

View full text Add to dashboard Cite

Food safety monitoring assays based on synthetic recognition structures such as aptamers are receiving considerable attention due to their remarkable advantages in terms of their ability to bind to a wide range of target analytes, strong binding affinity, facile manufacturing, and cost-effectiveness. Although aptasensors for food monitoring are still in the development stage, the use of an electrochemical detection route, combined with the wide range of materials available as transducers and the proper immobilization strategy of the aptamer at the transducer surface, can lead to powerful analytical tools. In such a context, employing aryldiazonium salts for the surface derivatization of transducer electrodes serves as a simple, versatile and robust strategy to fine-tune the interface properties and to facilitate the convenient anchoring and stability of the aptamer. By summarizing the most important results disclosed in the last years, this article provides a comprehensive review that emphasizes the contribution of aryldiazonium chemistry in developing electrochemical aptasensors for food safety monitoring.

show abstract

Aptamer-antibody sandwich assay for cytochrome c employing an MWCNT platform and electrochemical impedance

Cited by 34 publications

References 42 publications

Multifunctional Cytochrome c: Learning New Tricks from an Old Dog

Multifunctional Cytochrome c: Learning New Tricks from an Old Dog

Impedance Detection of 3‐Phenoxybenzoic Acid with a Noncompetitive Two‐site Phage Anti‐immunocomplex Assay

The Role of Aryldiazonium Chemistry in Designing Electrochemical Aptasensors for the Detection of Food Contaminants

Contact Info

Product

Resources

About