Carcinoembryonic Antigen In Clinical Samples Research Articles

Electrochemical deposition of Pd on MoS2 supported graphene nanoflakes over functionalised MWCNTs as an immunosensor for detection of lung cancer biomarker

An electrochemical immunosensor was designed to quantify carcinoembryonic antigen (CEA), which is regarded asa tumour marker and prognostic indicator. The glassy carbon electrode (GCE) surface was modified using MoS2, graphene nanoflakes (GNs), fMWCNTs, and electrodeposited PdNPs for the first time to prepare a Pd-MoS2-GNs@fMWCNTs/GCE. The platform was activated with monoclonal anti-CEA. The prepared nanocomposite material helps in improving the surface area and conductivity of the GCE. Moreover, PdNPs act as a linker between nanocomposite materials and anti-CEA, which enhances electron transport. The procedure used to analyse CEA involve sequential addition of CEA into the solution of 5 mM [Fe(CN)6]3-/4- prepared in 0.1 M PBS (pH 7.4) in the presence of fabricated electrode and DPV and EIS methods were used as detection technique. The change in signal response for the [Fe(CN)6]3-/4- redox reaction before and after CEA interaction is considered as the immunosensor response which is directly correlated with CEA concentration. Further, in DPV, the signal inhibition approach was used to measure CEA by monitoring the decrease in oxidation peak current of [Fe(CN)6]3-/4- due to the formation of CEA/anti-CEA immunocomplex. The electrochemical immunosensor demonstrated low LOD of 2 pg/mL and a correlation coefficient of 0.98 within a broad linear range of CEA concentration from 0.002 to 500 ng/mL. The fabricated immunosensor displayed excellent selectivity, repeatability, and stability. Further, the proposed immunosensor effectively measured CEA levels in human blood serum, making it an effective tool for testing CEA in clinical samples.

A biosensor based on graphene oxide nanocomposite for determination of carcinoembryonic antigen in colorectal cancer biomarker

Colorectal cancer is still a major global health concern, and early detection and accurate biomarker analyses are critical to its successful management. This paper describes the design and testing of a new biosensor based on a graphene oxide (GO) nanocomposite for the exact measurement of carcinoembryonic antigen (CEA), a well-known biomarker for colorectal cancer. The current study attempted to create a highly sensitive immunosensor for sensitive measurement of CEA based on a polypropylene-imine-dendrimer (PPI) and GO nanocomposite on GCE (PPI/GO/GCE). The PPI/GO nanocomposite served as an appropriate biocompatible nanostructure with a large surface area for immobilizing carcinoembryonic antigen (anti-CEA) and bovine serum albumin (BSA) molecules (BSA/anti-CEA/PPI/GO/GCE), thereby promoting the selectivity of electrochemical immunosensors, according to structural and electrochemical studies. Results showed that the BSA/anti-CEA/PPI/GO/GCE as a selective, sensitive, and stable immunosensor revealed a wide linear response from 0.001 to 2000 ng/mL, and a limit of detection of 0.3 pg/mL, which indicated comparable or better performance towards the CEA immunosensors in recent reports in the literature. This was due to the synergetic effect of the GO nanosheets and PPI with porous structure and more conductivity. Analytical results showed values of RSD (4.49%–5.04%) and recovery (90.00%–99.98%) are suitable for effective and accurate practical assessments in CEA in clinical samples. The capacity of the BSA/anti-CEA/PPI/GO/GCE to determine CEA in human blood was studied.

A novel electrochemical aptamer biosensor based on tetrahedral DNA nanostructures and catalytic hairpin assembly for CEA detection

At present, carcinoembryonic antigen (CEA) is a commonly used biomarker to diagnose cancers. Accurate and specific detection of CEA in clinical samples is of great significance for the diagnosis, treatment and prognosis of related cancers. In this research, we developed an enzyme-free electrochemical aptamer biosensor for highly sensitive detection of CEA based on tetrahedral DNA nanostructures (TDNs) and target-assisted catalytic hairpin assembly (CHA). A long single strand (Trigger), five oligonucleotide chains (S1-S5) and CEA aptamer were designed to form TDN-aptamer and TDN-H1 respectively. In the presence of CEA, the aptamer designed at the top of TDN-aptamer specifically bound to CEA, while trigger was released to open H1 immobilized on the top of TDN-H1. This reaction initiated the CHA cycle with the participation of H2 modified by Methylene blue (MB). Subsequently, a large number of MB modified H1-H2 double strands were connected to the electrode surface through TDN structures, which generated significant current signals. This proposed biosensor could detect CEA down to 0.04567 pg mL−1 with a wide linear range from 1 pg mL−1 to 30000 pg mL−1. Furthermore, the electrochemical aptamer biosensor could detect CEA in serum samples accurately, it provided an effective alternative platform for clinical detections of CEA.

An Electrochemical Aptasensor for Highly Sensitive Detection of CEA Based on Exo III and HCR Dual Signal Amplification

At present, Carcinoembryonic antigen（CEA）is considered as a broad-spectrum tumor biomarker, the accurate analysis of CEA in clinical samples can assist early diagnosis and treatment of cancer. Herein，a novel electrochemical aptasensor has been proposed for CEA detection based on Exo III and HCR dual signal amplification. The target CEA specifically is binded to aptamer region in H1 through a strong attraction, thereby triggering the CHA cycle to form plenty of H1@H2 duplex. Subsequently, the Exonuclease III digested complex and liberated the target to induce the first signal amplification, and generated a large number of trigger chains simultaneously. Then, these triggers can hybridize with the capture probes and MB-labeled S1 and S2, producing amplified electrochemical signal significantly on the electrode surface. The integration of HCR and EXO-III assisted target circulation endowed the sensor excellent analytical performance for the detection of CEA, with a wide linear range from 10 pg.ml -1 to 100 ng.ml -1 , high sensitivity of limit of detection (LOD) of 1.2 pg.ml -1 . What’s more, the biosensing strategy was successfully verified for directly identifying CEA in human serum samples and exhibited admirable stability and precision. Therefore, this elaborated sensor opens a new simple way for detecting CEA and exhibits a great promise in the early screening of tumor.

A Novel Electrochemical Aptamer Biosensor Based on Tetrahedral DNA Nanostructures and Catalytic Hairpin Assembly for CEA Detection

At present, carcinoembryonic antigen (CEA) is a commonly used biomarker to diagnose cancers. Accurate and specific detection of CEA in clinical samples is of great significance for the diagnosis, treatment and prognosis of related cancers. In this research, we developed an enzyme-free electrochemical apatmer biosensor for highly sensitive detection of CEA based on tetrahedral DNA nanostructures (TDNs) and target-assisted catalytic hairpin assembly (CHA). A long single strand (Trigger), five oligonucleotide chains (S1-S5) and CEA aptamer were designed to form TDN-aptamer and TDN-H1 respectively. In the presence of CEA, the aptamer designed at the top of TDN-aptamer specifically bound to CEA, while trigger was released to open H1 immobilized on the top of TDN-H1. This reaction initiated the CHA cycle with the participation of H2 modified by Methylene blue (MB). Subsequently, a large number of MB modified H1-H2 double strands were connected to the electrode surface through TDN structures, which generated significant current signals. This proposed biosensor could detect CEA down to 0.04567 pg mL-1 with a wide linear range from 1 pg mL-1 to 30000 pg mL-1. Furthermore, the electrochemical apatmer biosensor could detect CEA in serum samples accurately, it provided an effective alternative platform for clinical detections of CEA.

An enzyme-free fluorescent biosensor for highly sensitive detection of carcinoembryonic antigen based on aptamer-induced entropy-driven circuit.

Carcinoembryonic antigen (CEA) is a disease biomarker, which can reflect the existence of tumors. The accurate detection of CEA in clinical samples is highly valuable for diagnosis of tumors. Herein, we developed an enzyme-free fluorescent biosensor for highly sensitive detection of CEA based on an aptamer-induced entropy-driven circuit. The aptamer hairpin specifically bound to CEA to expose the locked domain. Then, the exposed domain could trigger disassembly of multiple fluorophore strands from the three-strand complexes with the aid of fuel strands, leading to the production of remarkable amplified fluorescent signals. The one-step and homogeneous method exhibited high specificity and a wide linear range from 10 pg mL-1 to 500 ng mL-1 with a low limit of detection of 4.2 pg mL-1. What's more, the whole detection process could be performed within 45 min and did not involve the use of any protein enzymes and antibodies. The developed strategy could also be applied to detect CEA in clinical samples with satisfactory results. Therefore, the strategy is an alternative sensing method for the detection of CEA.