Carcinoembryonic Antigen Concentration Research Articles

A multimode aptasensor based on hollow gold nanoparticles and structure switching of aptamer: Fast and sensitive detection of carcinoembryonic antigen

A fast and sensitive carcinoembryonic antigen (CEA) aptasensor with multiple detection modes was developed. It is based on hollow gold nanoparticles (HGNPs) and horse radish peroxidase (HRP) as both labels and signal amplification elements. In fabrication, capture DNA (cpDNA) was modified on magnetic beads, and reporter DNA (rpDNA) and HRP were co-modified on HGNPs. A combination DNA, containing a DNA aptamer (GAC-P) segment, hybridized with cpDNA and rpDNA, forming a satellite-structured biosensor. In response to CEA, the aptamer switches its structure, releasing rpDNA/HGNPs/HRP under magnetic separation. The surface plasmon resonance of HGNPs and the HRP enzyme activity of the supernatant were observed/detected with naked eyes, UV–vis spectroscopy, and electrochemistry techniques. The assay time is as short as ~45 min. CEA levels can be differentiated with naked eyes. The absorbance at 677 nm is linearly proportional to CEA concentration from 10 to 250 ng mL−1, with a limit of detection (LOD) of 8.6 ng mL−1. In contrast, the differential pulse voltammetry (DPV) peak current at -0.057 V is linearly correlated with CEA concentration in the range of 2−250 ng mL−1, with an LOD of 0.78 ng mL−1. The LOD values are lower than cancer patient threshold levels. The aptasensor exhibits negligible responses to interfering proteins. In addition, it displays good reproducibility, stability, accuracy and easiness of usage. The recovery rate for CEA spiked human serum samples are 100±5%. The developed assay strategy should provide a general platform for detecting other interested biomarkers.

Ratiometric electrogenerated chemiluminescence sensor based on a designed anti-fouling peptide for the detection of carcinoembryonic antigen

In this paper, an effective and accurate ratiometric electrochemiluminescence (ECL) system based on Au-luminol and CdS quantum dots (CdS QDs) as signal probes was constructed for detecting carcinoembryonic antigen (CEA). Polyaniline (PANI) and gold nanoparticles (AuNPs) strongly enhanced the electronic transfer efficiency and the specific area of the modified sensing surface, and improved the detection sensitivity. CdS QDs functionalized DNA strands functioned as cathode ECL emitters, and the aptamer of CEA modified with Au-luminol and quencher cyanine dye (Cy5) fluorophore functioned as anode ECL emitters. After the DNA capture probe combined with CEA aptamer, the negative potential ECL response of the CdS QDs was quenched because of electrochemiluminescence resonance energy transfer (ERET) between the Cy5 fluorophore and CdS QDs. However, the positive potential ECL response of Au-luminol can still be detected. The negative potential ECL response of CdS QDs was recovered, and the positive potential ECL response of Au-luminol decreased after CEA combined with its aptamer to take Cy5 and Au-luminol off the sensing interface. Additionally, the peptide provided effective anti-fouling performance in the detection of complex samples. The ratiometric ECL sensor with anti-fouling ability can sensitively determine the concentration of CEA in human serum.

An immunosensor for the determination of carcinoembryonic antigen by Surface Plasmon Resonance imaging

Carcinoembryonic antigen (CEA) is one of the biomarkers most commonly used to determine tumor activity. In this work, a Surface Plasmon Resonance imaging (SPRi) immunosensor was developed. The immunosensor consists of a cysteamine linker attached to a gold chip and mouse monoclonal anti-CEA antibody bonded by the “EDC/NHS protocol”. The formation of successive immunosensor layers was confirmed by AFM measurements. The concentration of the antibody was optimized. The linear response range of the developed immunosensor is between 0.40 and 20 ng mL−1, and it is suitable for CEA measurement in both blood cancer patients and healthy individuals. Only 3 μL of serum or plasma sample is required, and no preconcentration is used. The method has a precision of 2–16%, a recovery of 101–104% depending on CEA concentration, a detection limit of 0.12 ng mL−1 and a quantification limit of 0.40 ng mL−1. The method is selective (with respect to albumin, leptin, interleukin 6, metalloproteinase-1, metallopeptidase inhibitor 1 and CA 125/MUC16) and it was validated by comparison with the standard electrochemiluminescence method on a series of colorectal cancer blood samples.

Diagnosis Value of Combined Detection of Serum SF, CEA and CRP in Non-Small Cell Lung Cancer.

IntroductionThe aim of this study was to evaluate the clinical diagnostic value of combined detection of serum ferritin (SF), carcino-embryonic antigen (CEA) and C-reactive protein (CRP) in non-small cell lung cancer (NSCLC).MethodsThe study included 70 patients with NSCLC, 50 patients with benign lung disease and 50 healthy subjects. The serum concentrations of SF, CEA and CRP were determined by ELISA.ResultsThe results showed that the serum levels of SF, CEA and CRP in the NSCLC group were significantly higher than those of the benign lung disease group and the control group. The expression of the above three indexes in the lung cancer group III+IV was higher than that in the I+II group (P<0.05), and the expression of SF, CEA and CRP in the adenocarcinoma group was higher than that in the squamous cell carcinoma group. The difference is statistically significant (P<0.01). When the serum CEA, SF and CRP levels were used alone for diagnosis of NSCLC, CRP had the best diagnostic value. The area under the curve was 0.795. The diagnostic sensitivity and specificity were 81.8% and 66.8%, respectivelyWhen combining these three factors, the area under the curve was 0.890, and the sensitivity and specificity were 80.3% and 82.5%, respectively. The parameters above were also significantly different (all P<0.01).ConclusionThis study indicated that the combined detection of serum SF, CEA and CRP could improve the early diagnostic sensitivity of NSCLC, and may be used as a potential diagnostic method for NSCLC.

Serum Small Proline-Rich Protein 2A (SPRR2A) Is a Noninvasive Biomarker in Gastric Cancer.

Objective Since early diagnosis is very important for treating gastric cancer (GC), we aimed to detect serum small proline-rich protein2A (SPRR2A) to verify its diagnostic value for GC patients. Methods Serum samples were collected from 200 patients with GC, 100 patients with gastritis, 40 patients with rectal cancer (RC), 50 patients with colon cancer (CC), and 100 healthy controls. An enzyme-linked immunosorbent assay (ELISA) detection kit was applied to measure serum SPRR2A concentration. The correlations between serum SPRR2A and carcinoembryonic antigen (CEA), clinical pathological parameters of GC, and receiver operating characteristic (ROC) curve were also analyzed. Results The median serum SPRR2A concentration in GC patients was significantly higher than those in healthy controls and gastritis or colorectal cancer patients (P < 0.001). Serum SPRR2A concentration at a cut-off value of 80.7 pg/ml yielded an AUC of 0.851, with 75.7% sensitivity and 74.5% specificity for discriminating GC patients from healthy people. The AUC for the serum SPRR2A concentration combined with the CEA concentration was 0.876, with 79.7% sensitivity and 78.7% specificity. Similarly, serum SPRR2A discriminated GC patients from gastritis patients with an AUC of 0.820, with 90.5% sensitivity and 61.7% specificity. The AUC for the serum SPRR2A concentration combined with the CEA concentration was 0.848, with 87.8% sensitivity and 68.1% specificity. The serum SPRR2A levels in GC patients were associated with lymph node metastasis and the tumor-node-metastasis (TNM) stage (P < 0.05). There was an obvious difference in serum SPRR2A expression between GC patients before and after surgery (P < 0.0001). Conclusion These results suggest that serum SPRR2A can be used as an effective marker for GC.

A sandwich-type electrochemical immunosensor using Ag@CeO2-Au as a lable for sensitive detection of carcinoembryonic antigen

In this study, a sandwich-type electrochemical sensor was prepared to detect the carcinoembryonic antigen (CEA) sensitively by using silver@cerium oxide-gold (Ag@CeO2-Au) as carrier and gold nanoparticle – glassy carbon electrode (GCE) as platform. The Ag@CeO2 nanocomposite was prepared by selective REDOX method. Cerium (III) and silver (I) autocatalytic reactions do not require surfactants or organic compounds. In addition, CEA antibody (anti-CEA) was fixed by Au nanoparticles as a conductive matrix, and combined with Ag@CeO2-Au-anti-CEA to form a dual-signal amplification element mechanism. The immunosensor layer assembly process was validated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the linear relationship between the current signal and CEA concentration in the range of 0.1 pg mL−1 to 5 ng mL−1. Linear equation was I (μA) = 5.77 logcCEA (ng mL−1) + 26.32, and the detection limit was 0.032 pg mL−1 (S/N = 3). The fabricated immunosensor has good specificity, high stability and reproducibility. Moreover, it has good detection performance in human serum and has a broad application prospect in CEA clinical and medical research.

Abstract 3626: Genomic characterization of primary tumor in colorectal cancer according to serum carcinoembryonic antigen level

Abstract Background: Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers in colorectal cancer (CRC). High preoperative concentrations of CEA correlate with poor survival outcomes. Serial CEA measurements have been used for detecting recurrent CRC. However, the genomic characteristics of primary CRC according to the blood CEA level are still not clear. Though patients with low CEA levels are associated with good prognosis, some of these patients have progression of their tumor. It would aid in applying careful surveillance to identify a subset of patients at high risk for poor prognosis among those with low CEA level. In this study, the different types of molecular profiles were compared between CRC with low and high serum CEA levels. In addition, we compared the genomic characteristics between CRC without progression and with progression among patients with low CEA levels. Methods: Using data acquired from The Cancer Genome Atlas (TCGA), we performed survival and genomic analyses on 381 CRC patient samples with serum CEA levels. Differential mRNA expression, miRNA expression and DNA methylation were examined between CRC with low serum CEA levels (low CEA group; ≤ 5 ng/mL) and high serum CEA levels (high CEA group; &amp;gt; 5 ng/mL). Among the 140 patients with low CEA levels, the same analyses were performed between CRC without progression and with progression. Results: High CEA group was associated with higher pathologic stage, more venous and lymphatic invasion. High CEA group had worse overall and progression-free survival than low CEA group (p &amp;lt;0.001 and p &amp;lt;0.001, respectively). A total of 28 genes were identified as significantly differentially expressed genes between low and high CEA group. Functional annotation and pathway analyses of the differentially expressed genes identified the possible association of cell adhesion, cytokine-cytokine receptor interaction and Wnt signaling network. Two differentially expressed miRNAs (mir-486 and mir-509-1) and 3 differential CpG sites (cg07530063, cg24216966 and cg11622162) were identified between low and high CEA group. Between CRC without progression and with progression in low CEA group, we identified 20 differentially expressed genes that were associated with epithelial to mesenchymal transition and transport of organic acid, metal ion and amine compounds. Four differentially expressed miRNAs (mir-483, mir-9-1, mir-9-2, and mir-31) and no differential CpG sites were identified between CRC with and without progression. Conclusions: In this study, we have identified different molecular features between primary CRC with low and high CEA levels. Notably, specific genomic profiles may contribute to discriminating patients with poor outcomes in CRC with low CEA level. Citation Format: Ji Won Park, Manu Shivakumar, Eun Kyung Choe, Dokyoon Kim. Genomic characterization of primary tumor in colorectal cancer according to serum carcinoembryonic antigen level [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3626.

A novel electrochemical immunosensor for carcinoembryonic antigen based on Cu-MOFs-TB/polydopamine nanocarrier

Abstract Carcinoembryonic antigen (CEA) is a typical biomarker for lung cancer. It is very urgent to develop a sensitive and rapid method to assay CEA content in human serum. In this work, Cu-MOFs nanomaterials were synthesized by a hydrothermal method. Toluidine blue (TB) loaded mesoporous Cu-MOFs with polydopamine (PDA) coating were employed as a signal probe. The proposed sandwich immunosensor was fabricated by Cu-MOFs-TB/PDA, chitosan and MWCNTs on the glassy carbon electrode with a large surface area to immobilize primary antibodies (Ab1) and provide excellent conductivity. The sensitivity improvement of this new strategy was based on the destruction of the probe and the immune complex by HCl, which resulted in the closer distance between TB and the sensing electrode. Under optimal conditions, CEA was quantitatively detected with a wide linear range from 20 fg mL−1 to 200 ng mL−1, a low detection limit of 3.0 fg mL−1 (S/N = 3). In addition, the method showed good stability, selectivity, and reproducibility, which possessed wide potential applications for the detection of other tumour biomarkers.

Factors distinguishing invasive from pre-invasive adenocarcinoma presenting as pure ground glass pulmonary nodules

BackgroundTo investigate predictors of pathological invasiveness and prognosis of lung adenocarcinoma in patients with pure ground-glass nodules (pGGNs).MethodsClinical and computed tomography (CT) features of invasive adenocarcinomas (IACs) and pre-IACs were retrospectively compared in 641 consecutive patients with pGGNs and confirmed lung adenocarcinomas who had undergone postoperative CT follow-up. Potential predictors of prognosis were investigated in these patients.ResultsOf 659 pGGNs in 641 patients, 258 (39.1%) were adenocarcinomas in situ, 265 (40.2%) were minimally invasive adenocarcinomas, and 136 (20.6%) were IACs. Respective optimal cutoffs for age, serum carcinoembryonic antigen concentration, maximal diameter, mean diameter, and CT density for distinguishing pre-IACs from IACs were 53 years, 2.19 ng/mL, 10.78 mm, 10.09 mm, and − 582.28 Hounsfield units (HU). Univariable analysis indicated that sex, age, maximal diameter, mean diameter, CT density, and spiculation were significant predictors of lung IAC. In multivariable analysis age, maximal diameter, and CT density were significant predictors of lung IAC. During a median follow-up of 41 months no pGGN IACs recurred.ConclusionspGGNs may be lung IACs, especially in patients aged > 55 years with lesions that are > 1 cm in diameter and exhibit CT density > − 600 HU. pGGN IACs of < 3 cm in diameter have good post-resection prognoses.

Differential diagnosis of pancreatic cysts: A prospective study on the role of intra-cystic glucose concentration

BackgroundThe accuracy and costs of current diagnostic methods in the differential diagnosis of pancreatic cystic lesions still has ample room for improvement. AimsThe aim of the study was to confirm the diagnostic yield of intracystic glucose in the diagnosis of pancreatic cyst subtypes. MethodsWe prospectively recruited all patients who underwent Endoscopic Ultrasound with Fine Needle Aspiration of pancreatic cyst at our Institution. ResultsFifty-six patients were included in the study. We found that intracystic glucose concentration < 50 mg/dL was significantly more sensitive than a concentration of Carcinoembryonic Antigen > 192 ng/mL (93.6% vs 54.8%; p = 0.003) for the diagnosis of mucinous cysts. In terms of specificity, the two markers were not different (96% vs 100%; p = 1). Regarding the diagnosis of non-mucinous cysts, intracystic glucose concentration ≥ 50 mg/mL showed higher sensitivity than Carcinoembryonic Antigen level < 5 ng/mL (96% vs 72%) although a statistical significance could not be reached (p = 0.07). The two markers were not statistically different in terms of specificity (93.6% vs 87.1%; p = 0.62). ConclusionGiven its diagnostic performance and ease of measurement, intracystic glucose may replace Carcinoembryonic Antigen in the differential diagnosis of mucinous versus non-mucinous pancreatic cysts.

Highly sensitive detection of carcinoembryonic antigen using copper-free click chemistry on the surface of azide cofunctionalized graphene oxide

In this study, we reported a highly sensitive method for detecting carcinoembryonic antigen (CEA) based on an azide cofunctionalized graphene oxide (GO-N3) and carbon dot (CDs) biosensor system. Carbon dots-labeled DNA (CDs-DNA) combined with GO-N3 using copper-free click chemistry (CFCC), which quenched the fluorescence of the CDs via fluorescence resonance energy transfer (FRET). Upon the addition of CEA, fluorescence was recovered due to the combination of CEA and aptamer. Under optimal conditions, the relative fluorescence intensity was linear with CEA concentration in the range of 0.01–1 ng/mL (R2 = 0.9788), and the limit of detection (LOD) was 7.32 pg/mL (S/N = 3). This biosensor had a high sensitivity and good selectivity for CEA detection in serum samples, indicating that the novel sensor platform holds a great potential for CEA and other biomarkers in practical applications.

Newly developed primary malignancies in long-term survivors who underwent curative esophagectomy for squamous cell carcinoma of the esophagus.

We evaluated the efficacy of the long-term follow-up of patients who underwent radical esophagectomy for esophageal squamous cell carcinoma (ESCC) to screen for recurrence and new primary malignancies. We retrospectively collected 448 ESCC patients who underwent radical esophagectomy. Esophagogastroduodenoscopy, computed tomography, a stool test and the assessment of the serum concentration of squamous cell carcinoma antigen and carcinoembryonic antigen were performed annually, even over 5 years after esophagectomy. The incidence of ESCC recurrence and new primary malignancies was investigated. We enrolled 222 patients who survived at least 5years after esophagectomy. A total of 104 new primary malignancies occurred in 82 patients (36.9%) after esophagectomy. Twenty-one malignancies were in the head and neck region, 14 in the residual esophagus, 13 in the prostate and 11 in the gastric tube and lung. Patients who developed new primary malignancies after esophagectomy had a significantly higher Brinkman index than those without new malignancies. An endoscopic approach successfully treated 92.9% of carcinomas in the residual esophagus, 90.9% of cancers in the gastric tube and 42.9% of carcinomas in the head and neck region. The incidence of new primary malignancies was higher than the age-standardized incidence. Long-term follow-up and systemic screening may increase the probability of an early diagnosis and subsequent low-invasive treatment.

An Electrochemical Immunosensor for Sensitive Detection of the Tumor Marker Carcinoembryonic Antigen (CEA) Based on Three-Dimensional Porous Nanoplatinum/Graphene.

Carcinoembryonic antigen (CEA) is an important broad-spectrum tumor marker. The quantitative detection of a low concentration of CEA has important medical significance. In this study, three-dimensional porous graphene-oxide-supported platinum metal nanoparticles (3DPt/HGO) composites were prepared by a wet chemical method and modified on an electrode with enhanced conductivity, a large surface area, and good adsorption of immobilizing antibodies (Ab1). Horseradish peroxidase (HRP)-functionalized Au nanoparticles were fabricated to label the secondary antibodies (Ab2). The proposed immunosensor showed a good linear relationship in the range of 0.001–150 ng/mL for CEA and a detection limit of 0.0006 ng/mL. The immunosensor had high sensitivity, good stability and reproducibility, and has great application prospects for the clinical diagnosis of cancer.

A highly specific and sensitive fluorescence quenching probe for carcinoembryonic antigen detection based on tetrapod Au nanostars with Ag coating

The fluorescence quenching properties of Ag-coated Au tetrapod nanostars have been studied via fluorescence spectroscopic techniques. Because of the intense plasmonic light absorption and the corresponding fluorescence resonance energy transfer (FRET), the fluorescence quenching effect of Au tetrapod nanostars could be greatly enhanced by Ag coating. What’s more, the fluorescence quenching ability of Ag-coated Au tetrapod nanostars could be further increased by tuning the size of inner Au tetrapod nanostars or the thickness of the outer Ag coating. In the study of carcinoembryonic antigen (CEA) detection based on the fluorescence probe of Ag-coated Au tetrapod nanostars, surface modification of antibody conjugation has been carried out to guarantee the specificity. Under the optimized conditions, the fluorescence efficiency of the Ag-coated Au tetrapod nanostars probe exhibits a linear response to CEA concentration ranging from 10−280 pg/mL, and the corresponding theoretical detection limit (LOD) is as low as 8.2 pg/mL. Interference experiment results shows that the influence from the interfering proteins could be neglected in the detection, and it has been successfully applied to detect CEA in real samples. Compared with other optical detection techniques of CEA, this method based on fluorescence quenching of Ag-coated Au tetrapod nanostars has better performance because of the special geometry features including regular tips and Ag coating.

Serum and Saliva Levels of Cancer Antigen 15-3, Carcinoembryonic Antigen, Estradiol, Vaspin, and Obestatin as Biomarkers for the Diagnosis of Breast Cancer in Postmenopausal Women.

To find suitable biomarkers for diagnosis of Breast cancer in serum and saliva; also, to examine the correlation between salivary and serum concentrations of suitable biomarkers. This case-control study included 30 women with breast cancer as a case group and 30 healthy women as a matched control group. Blood and saliva specimens were collected from all participants. We evaluated serum and salivary cancer antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA), estradiol, vaspin, and obestatin concentrations. Mann-Whitney U testing and Spearman correlation coefficients were used for statistical analysis. Serum and salivary concentrations of estradiol were significantly higher in patients with breast cancer (BC) than in healthy women (P < .05). Also, serum CEA and salivary obestatin concentrations were significantly higher in BC patients than in the control group (P < .05). However, there was no significant difference between other parameters in patients with BC and controls. We observed a positive correlation between serum and salivary concentrations of CA15-3, as well as a negative correlation between serum and salivary concentrations of vaspin and obestatin. The results of this study demonstrated that concentrations of CEA and estradiol in serum, obestatin in serum and saliva, and estradiol in saliva were significantly different between the 2 groups.

Design and application of terahertz metamaterial sensor based on DSRRs in clinical quantitative detection of carcinoembryonic antigen.

The terahertz (THz) metamaterial biosensor has great potential for label-free and rapid specificity testing. Here, we designed two highly sensitive structures to detect the carcinoembryonic antigen (CEA) of the cancer biomarker in early stages. There was about 29 GHz (500 ng/ml) resonance shift for CEA with an insert grate metamaterial, which was consistent with simulation results. Moreover, the concentration of CEA was gained through the relationship between the cancer marker concentration and frequency shift (Δƒ). Our design and detection methods may provide a potential route for the early warning stages of cancer.

Simple “Signal‐Off” Electrochemical Aptasensor Based on Aptamer‐Cu3(PO4)2 Hybrid Nanoflowers/Graphene Oxide for Carcinoembryonic Antigen Detection

AbstractA signal‐off aptasensor was described based on well‐designed aptamer‐Cu3(PO4)2 hybrid nanoflowers&amp;graphene oxide composites (aptamer‐Cu3(PO4)2HNF&amp;GO) as an effective sensing platform and molybdophosphate precipitation as the signaling element. The aptamer, as the biorecognition unit grafted on aptamer‐Cu3(PO4)2HNF&amp;GO by the specificity of streptavidin and biotin, captured the carcinoembryonic antigen (CEA) through specific interaction. The molybdophosphate precipitation were formed by the reaction of the aptamer‐Cu3(PO4)2HNF&amp;GO with molybdate (MoO42−). However, the CEA‐aptamer bioconjugate layer films not only hinder electron transfer on the sensing interface, but also impede the formation of molybdophosphate precipitation, resulting that the current signal significantly decreased. So, a simple aptasensor for CEA was constructed with high sensitivity and signal‐off model. Under optimal experimental conditions using square wave voltammetry (SWV), the response peak currents decreases linearly with the logarithm of CEA concentrations in the range from 10 fg mL−1 to 500 ng mL−1. Also, the feasibility of its applications has also been demonstrated in the analysis of clinical serum samples.

Combining serum calcitonin, carcinoembryonic antigen, and neuron-specific enolase to predict lateral lymph node metastasis in medullary thyroid carcinoma.

BackgroundThis study aimed to investigate the clinical application of combined detection of serum calcitonin (Ctn), carcinoembryonic antigen (CEA), and neuron‐specific enolase (NSE) in predicting lateral lymph node metastasis (LLNM) in medullary thyroid carcinoma (MTC).MethodsSeventy‐four consecutive patients with MTC were enrolled. The relationship between serum Ctn, CEA, and NSE and LLNM was retrospectively analyzed by univariate analysis and logistic regression analysis. Furthermore, the clinical application of serum Ctn, CEA, and NSE combined detection in prediction of LLNM in MTC was also evaluated.ResultsThe rate of LLNM in this study was 48.64% (36/74).The expression levels of serum Ctn, CEA, and NSE in MTC with LLNM were significantly higher than those without LLNM (all P < .01). The area under the curve (AUC) predicted by serum Ctn, CEA, and NSE for LLNM in MTC patients was 0.867, 0.831, and 0.726, respectively, and the AUC of serum Ctn, CEA, and NSE combined detection was up to 0.890, higher than using a single biomarker. The sensitivity and specificity of serum Ctn, CEA, and NSE combined detection in prediction of LLNM were 88.89% and 81.57%, respectively.ConclusionsThe concentrations of serum Ctn, CEA, and NSE are closely related to LLNM in MTC, and the combined detection of all three biomarkers has a higher clinical value in the evaluation of MTC patients with LLNM. With more perspective study in the future, it would be an indicator of influencing personalized surgical strategy for different MTC patients.

Construction of electrochemical aptasensor of carcinoembryonic antigen based on toehold-aided DNA recycling signal amplification

Carcinoembryonic antigen (CEA), serves as a broad-spectrum tumor marker, and plays an important role in reflecting the existence, therapeutic evaluation, development, monitoring and prognosis of many types of cancer. An electrochemical aptasensor was designed for CEA detection based on toehold-aided DNA recycling. A partially hybridized Probe-4 (i.e. P2/P3/P4) was self-assembled on the surface of a gold electrode serving as the sensing platform. For CEA detection, CEA can bind with aptamer and free probe-1 (P1) can hybridize with P4, triggering toehold-aided DNA recycling. This enables the hybridization of more probe-5 (P5) (labeled with methylene blue (MB)) with P4, causing more methylene blue (MB) to be brought close to the electrode surface. An amplified current signal was thus generated due to more MB in the electrode surface. The proposed design showed good linearity between current response and log CEA concentration ranging from 0.1 to 50 ng·mL−1, with a detection limit of 20 pg mL−1. This aptasensor also showed high specificity for CEA detection, and was successfully used in spiked biological samples.

Sensitive detection of carcinoembryonic antigen (CEA) by a sandwich-type electrochemical immunosensor using MOF-Ce@HA/Ag-HRP-Ab2 as a nanoprobe

Sandwich-type electrochemical immunosensor was one of the main methods for detecting carcinoembryonic antigen (CEA). In this work, using Ce-MoF as the skeleton precursor, hyaluronic acid (HA) was coated on the surface of Ce-metal organic framework (Ce-MoF), which loaded with silver nanoparticles (Ag NPs) and horseradish peroxidase (HRP) to catalyze H2O2 and double amplified the current signal. Thus, a sensitive sandwich-type electrochemical immunosensor (Ce-MoF@ HA/Ag-HRP) was designed to detect carcinoembryonic antigen (CEA). The designed immunosensor used Au NPs to enhance the ability of attach more the first antibody (Ab1). This was due to Au NPs had good electrical conductivity and biocompatibility to accelerate electron transfer on the surface of the electrode. HA was riched in –COOH, –OH and had excellent biocompatibility, which can carry more Ag NPs to catalyze H2O2. Finally, the prepared sandwich-type electrochemical immunosensor had excellent biocompatibility and great catalytic performance. The immunosensor can be tested within 30 min and the logarithm of the current signal and CEA concentration showed a broad linear response range of 1 pg ml−1–80 ng ml−1, and the detection limit of CEA was 0.2 pg ml−1. More importantly, the proposed immunosensor had good reproducibility, selectivity, stability and without matrix effect. This confirmed that the proposed immunosensor had broad prospects in early clinical trials.