Carcinoembryonic Antibody Research Articles

Sensitive photoelectrochemical immunosensor for carcinoembryonic antigen detection based on copolymer of thiophene and thiophene-3-acetic acid modified phosphate-doped Bi2WO6

In this study, PO43− doped Bi2WO6 (BWO-PO) was prepared by hydrothermal method, and then copolymer of thiophene and thiophene-3-acetic acid (P(Th-T3A)) was chemically deposited on the BWO-PO surface. The introduction of PO43− created point defects, greatly improving the photoelectric catalytic performance of Bi2WO6; the copolymer semiconductor could form heterojunction with Bi2WO6 to promote the separation of photo-generated carriers, due to its proper band gap. Furthermore, the copolymer could enhance the light absorption ability and photo-electronic conversion efficiency. Hence, the composite had good photoelectrochemical properties. When it was combined with carcinoembryonic antibody through the interaction of –COOH groups of the copolymer and the end groups of antibody for constructing ITO-based PEC immunosensor, the resulting sensor exhibited superb response to carcinoembryonic antigen (CEA), with a wide linear range of 1 pg/mL−20 ng/mL, and a relatively low detection limit of 0.41 pg/mL. It also showed high anti-interference ability, stability, and simplicity. The sensor has been successfully applied to monitor the concentration of CEA in serum. The sensing strategy can also be applied to the detection of other markers by changing the recognition elements, hence it has good application potential.

Detection of non-small cell lung cancer marker CYFRA21-1 via Mxene-based immunoelectrochemical sensor

Chitosan (CS) provides more electrochemical active sites due to its large number of hydroxyl and amino groups. MXene can provide support sites for CS to construct novel MXene@CS composites. This work uses Ti3C2Tx@CS as a bioactive membrane. Gold nanoparticles and biotin-labeled horseradish peroxidase were made as amplification elements. The complexes formed by immunoreactivity with CYFRA21–1, streptavidin-labeled carcinoembryonic antibodies are immobilized on the Ti3C2Tx@CS. The assembled immunoelectrochemical sensor was used for the highly sensitive detection of CYFRA21–1. The results showed that the novel immunosensor exhibited a good linear range (2–20 ng/mL, R2 = 0.9941) with a detection limit of 1.7 ng/mL.

Clinical value of lncRNA CCAT1 in serum extracellular vesicles as a potential biomarker for gastric cancer.

Long non-coding RNAs (lncRNAs) in extracellular vesicles (EVs) are considered to be novel non-invasive biomarkers for gastric cancer (GC). lncRNA colon cancer-associated transcript 1 (CCAT1) is aberrantly expressed in certain types of cancer. However, the role of EV lncRNA CCAT1 in patients with GC remains unclear. The current study aimed to assess the expression levels of lncRNA CCAT1 in the serum EVs of patients with GC and evaluate its potential clinical value. EVs were isolated from serum using a commercial kit and ultracentrifugation, and were identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting. Serum EV lncRNA CCAT1 levels in patients with GC, chronic gastritis or atypical hyperplasia and healthy control subjects were detected by reverse transcription-quantitative PCR. Additionally, lncRNA CCAT1 was detected in GC and adjacent non-cancerous tissue samples. Serum EVs were successfully isolated and identified in all patients. The results revealed that serum EV lncRNA CCAT1 levels in patients with GC were significantly higher compared with those in healthy controls, patients with chronic gastritis or atypical hyperplasia (all P<0.05). Additionally, EV lncRNA CCAT1 expression levels were significantly different among various groups based on the depth of invasion, distant metastasis and the Tumor-Node-Metastasis stage. The area under the curve (AUC) value of EV lncRNA CCAT1 was 0.890 [95% confidence interval (CI), 0.826–0.937] with 79.6% sensitivity and 92.6% specificity. The combination of EV lncRNA CCAT1 and carcinoembryonic antibody produced an AUC value of 0.910 (95% CI, 0.849–0.951) with the sensitivity and specificity of 80.5 and 92.6%, respectively. In addition, lncRNA CCAT1 was determined to be stable in serum EVs. The expression levels of lncRNA CCAT1 in GC tissue were positively correlated with those in serum EVs, and high levels of lncRNA CCAT1 were associated with a low disease-free survival rate in patients with GC. The results of the present study demonstrated that serum EV lncRNA CCAT1 levels were upregulated in patients with GC compared with those healthy subjects and patients with other illnesses, and may therefore be used as a novel biomarker for this type of cancer.

Cu-Au nanocrystals functionalized carbon nanotube arrays vertically grown on carbon spheres for highly sensitive detecting cancer biomarker

A three-dimensional hierarchical nanohybrid based on Cu-Au bimetallic nanocrystals integrated carbon nanotube arrays vertically grown on carbon spheres was successfully developed as an active platform for sensing application. Such nanohybrid can provide abundant active sites and act as an exceptional platform for immobilizing highly dense and well-dispersed carcinoembryonic antibody (anti-CEA) to sensitively detect CEA, an emerging biomarker of various cancer diseases. Due to the unique nanoarchitecture with altered electronic structure of Cu-Au bimetallic catalyst and enhanced interactions between components, such nanohybrid based biosensor demonstrated excellent electrochemical performance towards CEA detection with great sensitivity, wide linear detection range (0.025–25 ng/mL), very low limit of detection (0.5 pg/mL), and good selectivity. The results imply that this sensor has great potential to offer essential information for cancer diagnosis and management with great clinical importance.

Colorimetric Biosensor for Detection of Cancer Biomarker by Au Nanoparticle-Decorated Bi2Se3 Nanosheets.

The colorimetric biosensors have attracted intensive interest; however, their relatively low sensitivity limits their applications in clinic detection. Herein, we develop an effective colorimetric biosensor based on highly catalytic active Au nanoparticle-decorated Bi2Se3 (Au/Bi2Se3) nanosheets. Au/Bi2Se3 nanosheets are facilely synthesized by simply sonicating Au precursor with the as-synthesized Bi2Se3 nanosheets in aqueous solution. Because of the low redox potential and typical topological insulating properties, Bi2Se3 nanosheets is capable of providing and accumulating electrons on its surface. Such unique properties of Bi2Se3 nanosheets contribute to strong synergistic catalytic effects with Au nanoparticles, particularly when Au/Bi2Se3 nanosheets are utilized for catalyzing the reduction of 4-nitrophenol (4-NP) by NaBH4 (K = 386.67 s-1g-1). The excellent catalytic activity of Au/Bi2Se3 nanosheets can be "switched off" upon treatment of antibody of cancer biomarker such as anticarcinoembryonic antibody (anti-CEA). Addition of the corresponding antigen such as cancer biomarker carcinoembryonic antibody (CEA) can successively help "switch on" the catalytic activity of Au/Bi2Se3 nanosheets, where the resuming degree however depends on the antigen concentration. This cancer biomarker depended catalytic behavior therefore allows Au/Bi2Se3 nanosheets to be employed as a colorimetric sensor for detection of a particular cancer biomarker, for the reduction of 4-nitrophenol (4-NP) by NaBH4 itself involves apparent color change. The sensor shows high sensitivity and selectivity for the cancer biomarker, even for a concentration as low as 160 pg/mL for CEA, which fully satisfies the requirement for real clinical applications. The developed colorimetric sensor shows good generality for detection of different types of cancer biomarkers, such as α-fetoprotein (AFP) and prostate-specific antigen (PSA). Furthermore, real clinic sample analyzing result shows that the prepared biosensor is efficient for detection of CEA, providing an alternative method in cancer diagnosis.

Attomole Antigen Detection Using Self-Electrochemiluminous Graphene Oxide-Capped Au@L012 Nanocomposite.

In this work, a self-electrochemiluminous graphene oxide-capped Au@L012 nanocomposite was prepared as the label at carcinoembryonic (CEA) antibody to detect attomole CEA antigen. To maximize the luminescence intensity, L012 molecules (luminol analogue) were linked with poly(diallyldimethylammonium chloride) (PDDA) to form positive charged PDDA&L012 pairs, which were modified on negative charged Au@nafion nanoparticles to construct a Au@nafion@PDDA&L012 (Au@L012) complex. Graphene oxide with carboxyl groups was capped at Au@L012 complex through electrostatic interaction to serve as an effective matrix for the covalent attachment of CEA antibody. As compared with the traditional used Au nanoparticles modified with luminol, ∼740-fold increase of self-luminescence was observed from this new complex so that CEA antigen as low as 0.5 amol at electrode surface was measurable in the absence of any coreactant. Moreover, the nanocomposite was attached with CEA antigen at MCF-7 cells allowing the detection of CEA antigen from 72 cells. The success in the detection of surface antigen at small population of cells suggested the self-electrochemiluminescence nanocomposite as the new and biosafe label for the ECL immunoassay, which might push the application of ECL for the cellular immunoanalysis.

Fine-Needle Aspiration with Immunohistochemistry Using a Modified Scrape Cell Block Technique for the Diagnosis of Thyroid and Parathyroid Nodules

Objective: To evaluate the diagnostic accuracy of a modified scrape cell block (SCB) technique in a large series of patients. The technique was especially developed and tested for fine-needle aspiration of thyroid and parathyroid nodules. Study Design: Eighty-two ultrasound-guided fine-needle aspiration specimens with the sonographic aspect of a thyroid (n = 33) or a possible parathyroid nodule (n = 49) were studied. Immunohistochemistry (IHC) was used on cell blocks containing plasma, thromboplastin, and selected 3-dimensional cell aggregates scraped off Papanicolaou-stained smears. Antibodies for chromogranin A, thyroglobulin, parathyroid hormone, calcitonin, and carcinoembryonic antibody (CEA) were used. In cases of reduced immunosensitivity or suspected metastases or rare primary tumors, additional IHC markers were employed. Results: Chromogranin A was expressed in all 28 parathyroid adenomas (PA), in 7 of 8 hyperplastic parathyroid glands, and in 13 of 14 medullary thyroid carcinomas (MTC). When combining positivity for chromogranin A and calcitonin/CEA, the specificity for the detection of MTC was 100%. Parathyroid hormone was expressed in 26 of 36 parathyroid nodules (72.2%). When combining follicular microarchitecture and expression of chromogranin A, the specificity for the detection of parathyroid tissue was 97%. Conclusion: With the modified SCB technique, accurate cytological diagnoses were obtained in 97.6% of 82 patients.

Polyaniline modified flexible conducting paper for cancer detection

We report results of studies relating to the fabrication of a flexible, disposable, and label free biosensing platform for detection of the cancer biomarker (carcinoembryonic antigen, CEA). Polyaniline (PANI) has been electrochemically deposited over gold sputtered paper (Au@paper) for covalent immobilization of monoclonal carcinoembryonic antibodies (anti-CEA). The bovine serum albumin (BSA) has been used for blocking nonspecific binding sites at the anti-CEA conjugated PANI/Au@Paper. The PANI/Au@Paper, anti-CEA/PANI/Au@Paper, and BSA/anti-CEA/PANI/Au@Paper platforms have been characterized using scanning electron microscopy, X-ray diffraction, Fourier transmission infrared spectroscopy, chronoamperometry, and electrochemical impedance techniques. The results of the electrochemical response studies indicate that this BSA/anti-CEA/PANI/Au@paper electrode has sensitivity of 13.9 μA ng−1 ml cm2, shelf life of 22 days, and can be used to estimate CEA in the range of 2–20 ng ml−1. This paper sensor has been validated by detection of CEA in serum samples of cancer patients via immunoassay technique.

Novel Electrochemical Immunoassay for Carcinoembryonic Antigen Using Ferrocenyl Polymer Nanospheres

ABSTRACTA new electrochemical immunoassay based on a sandwich format was developed for carcinoembryonic antigen using ferrocenyl polymer nanospheres as the recognition elements. Ferrocenyl nanospheres were synthesized by coordination polymerization and characterized by transmission electron microscopy, energy dispersive X-ray spectrometry, and infrared spectroscopy. Monoclonal carcinoembryonic antibodies were immobilized on a nanogold-modified gold electrode to enhance the sensitivity. Polyclonal carcinoembryonic antibodies were conjugated on ferrocenyl polymer nanospheres. Under the optimal conditions, the electrochemical signal increased with the concentration of the analyte from 0.01 to 50 ng mL−1 with a limit of detection equal to 0.004 ng mL−1. The immunosensor provided acceptable reproducibility with coefficients of variation below 10%.

Synthesis and characterization of C@CdS dots in aqueous solution and their application in labeling human gastric carcinoma cells

Colloidal carbon spheres coated with cadmium sulfide nanoparticle quantum dots (C@CdS dots) with the particle size smaller than 50 nm were synthesized by an aqueous approach. The effects of different reaction times, temperatures, and pH values were carefully investigated to optimize the synthesis conditions. The as-prepared C@CdS dots were linked with mouse anti-human carcinoembryonic antigen antibody and goat anti-mouse immunoglobulin (IgG) to directly and indirectly label fixed human gastric carcinoma cells, respectively. The cytotoxicity of the C@CdS dots was also tested using the human gastric carcinoma cells. No apparent cytotoxicity was observed, which suggested the potential application of the as-prepared C@CdS dots in bioimaging.

Sandwich-type amperometric immunosensor for cancer biomarker based on signal amplification strategy of multiple enzyme-linked antibodies as probes modified with carbon nanotubes and concanavalin A

A sandwich-type amperometric immunosensor for carcinoembryonic antigen was fabricated by using functionalized carbon nanotubes decorated with concanavalin A along with horseradish peroxidase-labeled carcinoembryonic secondary antibodies. The HRP-Ab2 was assembled onto carbon nanotubes templates based on the biospecific affinity between concanavalin A and HRP. The carcinoembryonic antibody was immobilized on the gold electrode modified by monolayer cysteine. The response is linear in the range of 0.05–5ngmL−1 and 5–200ngmL−1, with a detection limit of 0.018ngmL−1. The biosensor can be used in serum directly.

One-step synthesis of graphene oxide–thionine–Au nanocomposites and its application for electrochemical immunosensing

Here we report a one-step approach to synthesize graphene oxide–thionine–Au (GO–Thi–Au) nanocomposites using the synergistic effect of Thi and GO. Thi molecules adsorbed on the nanocomposites still kept the property of electroactive redox. Meanwhile, the resulting Au nanoparticles (AuNPs) of the nanocomposites offer active sites for the immobilization of biomolecules. The GO–Thi–Au nanocomposites are successfully employed for the fabrication of a simple, label-free, and ultrasensitive electrochemical immunosensor. Using carcinoembryonic antibody (anti-CEA) and carcinoembryonic antigen as model systems, the immunosensor showed an ultralow detection limit of 0.05fgmL−1, and a linear calibration plot was obtained in a wide concentration range from 0.1fgmL−1 to 1×109fgmL−1.

Fabrication of an ultrasensitive electrochemical immunosensor for CEA based on conducting long-chain polythiols

A conducting long-chain polythiols (poly (2-aminothiophenol), PATP) was synthesized by a chemical polymerization process and combined with Au nanoparticles (AuNPs) to prepare a novel, sensitive and label-free electrochemical biosensor by adsorption of carcinoembryonic antibody (anti-CEA) on the PATP–AuNPs modified gold electrode. Differential pulse voltammetry (DPV) was used to characterize the recognition of carcinoembryonic antigen (CEA). Under the optimized conditions, the proposed immunosensor displayed a good amperometric response to CEA with linear range from 1fgmL−1 to 10ngmL−1 and a detection limit of 0.015fgmL−1 (signal/noise=3). The results demonstrated that the immunosensor has advantages of high sensitivity, wide linear range, good repeatability, and good selectivity. Importantly, the results of the detection of clinical serum specimens with the proposed sensor were well consistent with the data determined by micropartical enzyme immunoassay (MPEI), showing that the present work provides a promising ultrasensitive immunoassay strategy for clinical applications.

Preoperative carcinoembryonic antibody is predictive of distant metastasis in pathologically T1 colorectal cancer after radical surgery

To identify the predictors of distant metastasis in pathologically T1 (pT1) colorectal cancer (CRC) after radical resection. Variables including age, gender, preoperative carcinoembryonic antibody (CEA) level, tumor location, tumor size, lymph node status, and histological grade were recorded. Patients with and without metastasis were compared with regard to age, gender, CEA level and pathologic tumor characteristics using the independent t test or χ(2) test, as appropriate. Risk factors were determined by logistic regression analysis. Metastasis occurred in 6 (3.8%) of the 159 patients during a median follow-up of 67.0 (46.5%) mo. The rates of distant metastasis in patients with pT1 cancer of the colon and rectum were 6.7% and 2.9%, respectively (P < 0.001). The rates of distant metastasis between male and female patients with T1 CRC were 6.25% and 1.27%, respectively (P < 0.001). The most frequent site of distant metastasis was the liver. Age (P = 0.522), gender (P = 0.980), tumor location (P = 0.330), tumor size (P = 0.786), histological grade (P = 0.509), and high serum CEA level (P = 0.262) were not prognostic factors for lymph node metastasis. Univariate analysis revealed that age (P = 0.231), gender (P = 0.137), tumor location (P = 0.386), and tumor size (P = 0.514) were not risk factors for distant metastasis after radical resection for T1 colorectal cancer. Postoperative metastasis was only significantly correlated with high preoperative serum CEA level (P = 0.001). Using multivariate logistic regression analysis, high preoperative serum CEA level (P = 0.004; odds ratio 15.341; 95%CI 2.371-99.275) was an independent predictor for postoperative distant metastasis. The preoperative increased serum CEA level is a predictive risk factor for distant metastasis in CRC patients after radical resection. Adjuvant chemotherapy may be necessary in such patients, even if they have pT1 colorectal cancer.

Electrochemical immunoassay for carcinoembryonic antigen based on signal amplification strategy of nanotubular mesoporous PdCu alloy

Interests in using nanoporous metals for biosensing applications have been increasing. Herein, nanotubular mesoporous PdCu (NM-PdCu) alloy is used to fabricate a novel label-free electrochemical immunosensor for cancer biomarker carcinoembryonic antigen (CEA). It operates through physisorption of anti-CEA on NM-PdCu and the mixture of sulfonated graphene sheets (HSO3-GS) and thionine (TH) functionalized glassy carbon electrode interface as the detection platform. In this study, chitosan (CS)-PdCu is bound very strongly to carcinoembryonic antibody (anti-CEA), because of the good electron conductivity, high surface area, and good biocompatibility. CS-PdCu is immobilized on electrodes by electrostatic interactions between the negatively charged sulfo group of HSO3-GS and the abundant positively charged amino groups of chitosan. TH acts as the redox probe. Under the optimized conditions, the electrochemical immunosensor exhibits a wide working range from 0.01 to 12ng/mL with a low detection limit of 4.86pg/mL. The accuracy, reproducibility, and stability of the immunosensor are acceptable. The assay is evaluated for real serum samples, receiving satisfactory results. The nanoporous metal materials-based immunoassay provides a promising approach in clinical application and thus represents a versatile detection method.

Biofunctionalized dendritic polyaniline nanofibers for sensitive electrochemical immunoassay of biomarkers

Multi-armed dendritic polyaniline nanofibers (MPANFs) were first synthesized and functionalized with horseradish peroxidase (HRP) and carcinoembryonic antibody (anti-CEA) for highly efficient electrochemical immunoassay of carcinoembryonic antigen (CEA, as a model analyte here) in this work. Transmission electron microscope (TEM) and scanning electron microscope (SEM) techniques were employed to characterize the synthesized MPANFs. By using anti-CEA-conjugated core-shell gold-Fe(3)O(4) nanocomposites (GoldMag) as immunosensing probes and biofunctionalized MPANFs as molecular tags, a new sandwich-type homogeneous immunoassay strategy was developed for the determination of CEA by coupling with a home-made flow-through magneto-controlled microfluidic device. Under optimal conditions, the electrochemical immunoassay exhibited a wide dynamic range of four orders of magnitude from 1.0 pg mL(-1) to 50 ng mL(-1) with a low detection limit of 0.1 pg mL(-1) CEA at 3σ. Intra- and inter-assay coefficients of variation were below 10%. The assayed results for clinical serum specimens with the electrochemical immunoassay were received in good accordance with the results obtained from the referenced enzyme-linked immunosorbent assay (ELISA) method.

Sensitive label-free electrochemical immunoassay based on a redox matrix of gold nanoparticles/Azure І/multi-wall carbon nanotubes composite

A sensitive label-free electrochemical immunosensing platform was designed by a redox matrix of gold nanoparticles (GNPs), Azure І and multi-wall carbon nanotubes (MWCNT) self-assemblying nanocomposite. To construct the immunosensor, MWCNT was first dispersed in Nafion (Nf) to obtain a homogeneous solution and then it was dropped on the surface of the gold electrode (Au). Then the positively-charged redox molecule, Azure І, was entrapped into MWCNT–Nf film to form a redox nanostructural membrane. Next, the negatively charged gold nanoparticles (GNPs) were assembled to the interface through the electrostatic force. Finally, carcinoembryonic antibody molecules could be absorbed into the GNPs/Azure І/MWCNT–Nf immobilization matrix. Using carcinoembryonic antigen (CEA) as a model protein, the electrochemical immunosensor exhibited good stability and reproducibility, as well as good selectivity and storage stability. This strategy presented a promising platform for sensitive and facile monitoring of CEA.

A Sensitive Label-free Amperometric CEA Immunosensor Based on Graphene-Nafion Nanocomposite Film as an Enhanced Sensing Platform

A novel approach to fabricate a label-free amperometric immunosensor for the detection of carcinoembryonic antigen (CEA) was described. Herein, methylene blue (MB), gold nanoparticles (AuNPs) and carcinoembryonic antibody (anti-CEA) were layer-by-layer assembled on the graphene-Nafion nanocomposite film-modified electrode by means of a self-assembling technique and the opposite-charged adsorption. Subsequently, the stepwise self-assembling procedure of the immunosensor was further characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The factors influencing the performance of the resulting immunosensor were studied in detail. The developed procedure showed improved features, including larger amount and higher immunoactivity of the immobilized antibody and repeatable regeneration of the sensor, as well as direct, rapid and simple determination for the antigen without multiple separation and labeling steps. The immunosensor could detect the target protein in a range of 0.5 to 120 ng/mL with a limit of 0.17 ng/mL (at 3σ). Finally, the immunosensing system was evaluated on several clinical samples. Analytical results were found to be in satisfactory agreement with those detected by the enzyme-linked immunosorbent assay (ELISA) method, indicating that this new method was a promising alternative tool for clinical diagnosis.

Carcinoembryonic Antigen Admittance Biosensor Based on Au and ZnO Nanoparticles Using FFT Admittance Voltammetry

In this work, a highly sensitive carcinoembryonic antigen fast Fourier transform admittance biosensor is introduced. The proposed biosensor is based on bilayer films of ZnO/Au nanoparticles as an immobilization matrix. These layers are prepared by self-assembly and deposition method on a gold electrode surface, respectively. Carcinoembryonic antibody (anti-CEA) was immobilized on gold nanoparticles and positively charged horseradish peroxidase (HRP) was used to block sites against nonspecific binding. The admittance biosensor was developed based on fast Fourier transform continuous square wave voltammetry, which produces a sensitive, fast (less than 20 s) and reliable response for determination of carcinoembryonic antigen. The technique was applied as a detector in a flow injection system. The admittances reduction current of the biosensor decreases linearly in two concentrations ranges of CEA from 0.1 to 70 ng/mL and from 70 to 200 ng/mL with a detection limit of 0.01 ng/mL in presence of 0.5 mM H(2)O(2) as an eluent solution.

A highly sensitive resonance scattering spectral assay for carcinoembryonic antigen using immunonanogold as probe and nanocatalyst of NH2OH–Cu(II) particle reaction

Nanogold of 10 nm was used to label carcinoembryonic antigen antibody (CEAAb) to prepare a probe (Au-CEAAb) for carcinoembryonic antigen (CEA). In a Na₂HPO₄-NaH₂PO₄ buffer solution of pH 6.8, CEA reacted with Au-CEAAb to form a big Au-CEAAb-CEA immunocomplex that can be removed by centrifugation. The unreacted Au-CEAAb in the centrifugal supernatant exhibited catalytic effect on the Cu₂O particle reaction, and the Cu₂O particles displayed a resonance scattering (RS) peak at 602 nm. When CEA increased, the RS intensity at 602 nm decreased, and the decreased RS intensity (ΔI (602 nm)) was linear to CEA concentration (C (CEA)) in the range of 0.02-12 ng mL(-1), with the regression equation of ΔI (602 nm) = 27.1 C (CEA) + 3.3, correlation coefficient of 0.9978 and detection limit of 3 pg mL(-1) CEA. The proposed method was applied to detect CEA in real samples, with satisfactory results.