Impedimetric Detection of Calreticulin by a Disposable Immunosensor Modified with a Single-Walled Carbon Nanotube-Conducting Polymer Nanocomposite

Abstract

A label-free impedimetric immunosensing system was constructed for ultrasensitive determination of the calreticulin (CALR) biological marker in human serum samples utilizing an electrochemical impedance spectroscopy analysis technique for the first time. The new biosensor fabrication procedure consisted of electrodeposition of single-walled carbon nanotubes (SWCNTs) incorporating polymerization of an oxiran-2-yl methyl 3-(1H-pyrrol-1-yl) propanoate monomer (Pepx) onto a lowcost and disposable indium tin oxide (ITO) electrode. The SWCNTs-PPepx nanocomposite layer was prepared onto the ITO after the one-step fabrication procedure. The fabrication procedure of the immunosensor and the characteristic biomolecular interactions between the anti-CALR and CALR were characterized by electrochemical analysis and morphological monitoring techniques. Under optimum conditions, the proposed biosensor was responsive to CALR concentrations over the detection ranges of 0.015−60 pg/mL linearly, and it had a very low detection limit (4.6 fg/mL) and a favorable sensitivity (0.43 kΩ pg −1 mL cm −2 ). The reliability of the biosensor system in clinical analysis was investigated by successful quantification of CALR levels in human serum. Moreover, the repeatability and reproducibility results of the biosensor were evaluated by using Dixon, Grubbs, T-test, and F-tests. Consequently, the proposed biosensor was a promising method for scientific, rapid, and successful analysis of CALR in human serum samples.

Carboxyethylsilanetriol-Coated Magnetic Nanoparticles as an Ultrasensitive Immunoplatform for Electrochemical Magnetosensing of Cotinine

“…The charge transfer resistance ( R ct ) is represented by the semicircle diameter in the impedance spectrum. R ct reflects the kinetic electron transfer events occurring at the electrode interface of the redox probe. − Inset of Figure A shows the applied Randles equivalent circuit that analyzes the obtained EIS signal at each step. In this circuit, R s , W , and CPE are the ferri-ferro electrolyte resistance, Warburg impedance caused by ion diffusion, and constant phase element, respectively. , After each modification step, R ct was calculated to follow the electron transport process on the electrode surface.…”

Electrochemistry Test Strip as Platform for In Situ Detection of Blood Levels of Antipsychotic Clozapine in Finger-Pricked Sample Volume

“…After cleaning, the CTS was coated with Nafion solution to create a selective layer that can block interfering substances such as ascorbic acid, uric acid, etc. [ 11 ]. The performance of electrochemical sensors increased with the surface modification strategy.…”

“…It offers many advantages over traditional techniques, including low cost, quick response time, simplicity, robustness, and high sensitivity towards low analyte concentrations [ 8 , 9 , 10 ]. Different types of electrode platforms have been used in electrochemical sensors, including gold electrodes [ 11 ], Indium thin oxide (ITO) coated-glass electrodes [ 12 ], glassy carbon electrodes [ 13 ], and carbon fiber electrodes [ 14 ]. Recently, there has been a growing interest in using screen-printed electrodes (SPEs) for electroanalytical research.…”

Label-Free Electrochemical Biosensor Platforms for Cancer Diagnosis: Recent Achievements and Challenges

“…Various electrochemical techniques have been used for antibody-based biosensors for gastric cancer [ 88 ], breast cancer [ 89 , 90 , 91 , 92 ], ovarian cancer [ 93 , 94 , 95 , 96 ], bladder cancer [ 97 ], colorectal cancer [ 98 ], lung cancer [ 99 ], prostate cancer [ 100 , 101 , 102 , 103 , 104 , 105 ], liver cancer [ 106 ] and more. In a study for a label-free electrochemical immunosensor developed for early-stage detection of prostate cancer, the surface of the indium tin oxide electrode was firstly coated with chitosan and reduced graphene oxide, and then the specific polyclonal anti-prostate-specific antigen (PSA) antibody as a recognition element was immobilized on the surface.…”