An Exfoliated Graphite-Based Electrochemical Immunosensor on a Dendrimer/Carbon Nanodot Platform for the Detection of Carcinoembryonic Antigen Cancer Biomarker

Abstract

An electrochemical immunosensor for the quantification of carcinoembryonic antigen (CEA) using a nanocomposite of polypropylene imine dendrimer (PPI) and carbon nanodots (CNDTs) on an exfoliated graphite electrode (EG) is reported. The carbon nanodots were prepared by pyrolysis of oats. The nanocomposites (PPI and CNDTs) were characterized using X-ray powder diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The proposed immunosensor was prepared on an exfoliated graphite electrode sequentially by drop coating CNDTs, the electrodeposition of G2-PPI (generation 2 poly (propylene imine) dendrimer), the immobilization of anti-CEA on the modified electrode for 80 min at 35 °C, and dropping of bovine serum albumin (BSA) to minimize non-specific binding sites. Cyclic voltammetry was used to characterize each stage of the fabrication of the immunosensor. The proposed immunosensor detected CEA within a concentration range of 0.005 to 300 ng/mL with a detection limit of 0.00145 ng/mL by using differential pulse voltammetry (DPV). The immunosensor displayed good stability and was also selective in the presence of some interference species such as ascorbic acid, glucose, alpha-fetoprotein, prostate-specific antigen and human immunoglobulin. Furthermore, the fabricated immunosensor was applied in the quantification of CEA in a human serum sample, indicating its potential for real sample analysis.

Electrochemical and Photoelectrochemical Immunosensors for the Detection of Ovarian Cancer Biomarkers

“…Anti-CEA was then added to the modified electrode for CEA detection which resulted in a highly specific, repeatable, and stable biosensor that also has potentials in clinical applications for detecting CEA antigen. In 2019, Idris et al [45] constructed a simple EC immunosensor based on a polypropylene imine dendrimer (PPI) and carbon nanodots (CNDTs) nanocomposite decorated on an exfoliated graphite electrode (EG) for CEA detection. The CNDTs, which were synthesized from oats through pyrolysis, was drop-coated onto a carbon nanotube-modified exfoliated graphite electrode.…”

Gold‐dendrimer Nanocomposite Based Electrochemical Sensor for Dopamine

“…This peak enhancement will be beneficial for the electrooxidation of dopamine. Dendrimer has been reported to show a synergic peak enhancement effect when combined with other nanoparticles [26,27,28].…”

Nanostructure-Based Electrochemical Immunosensors as Diagnostic Tools

“…CEA is a tumor marker usually present in human serum (2.5-5 ng/mL) [111] and over-expressed when colon carcinomas, pancreas, liver, lung and ovarian cancer occur [112]. Recently Idris et al have developed a new platform based on nanocomposite of polypropylene imine dendrimer (PPI) and carbon nanodots (CNDTs) on an exfoliated GPH electrode (EGE) for the detection of CEA [113]. CNDTs and PPI properties of chemical stability, excellent biocompatibility and high surface area allowed a label-free electrochemical immunosensor with the direct immobilization of the anti-CEA on the nanocomposite platform.…”