Carcinoembryonic Antigen Concentration Research Articles

An electrochemical immunosensor for CEA detection based on Au-Ag/rGO@PDA nanocomposites as integrated double signal amplification strategy

An electrochemical immunosensor for quantitation of carcinoembryonic antigen (CEA) based on Au-Ag/rGO@PDA nanocomposites for dual signal amplification strategy was designed. Polydopamine-coated Ag/graphene hybrids were synthesized by one-step reduction and functionalization, and the dopamine was introduced to replace some reducing agents that are harmful to organisms. Silver nanoparticles modified on the electrodes produced sensitive electrochemical redox peaks. When different amounts of protein (antigen, antibody, bovine serum protein, etc.) were adsorbed on the surface of nano-silver, the surface of nano-silver was covered. The electrochemical redox peak of silver particles decreased due to the change of the effective area of bare silver particles which could react with electrodes. In addition, CEA-antibody (anti-CEA) was immobilized into a biocompatible nanocomposite of Au nanoparticles as a conductive matrix, and CEA-antibody (anti-CEA) was combined with Ag/rGO@PDA to form a dual signal amplifying element. Under optimal condition, the linear relationship was obtained from 0.001 ng mL−1 to 80 ng mL−1 between current signal and CEA concentration with a detection limit of 0.286 pg mL−1 (signal-to-noise ratio is 3). The label-free electrochemical immunosensor has been successfully applied to human serum detection due to good selectivity, stability and reproducibility.

Gene Expression of the Circulating Long Noncoding RNA H19 and HOTAIR in Egyptian Colorectal Cancer Patients.

Background: HOX transcript antisense RNA (HOTAIR) and H19 are two long noncoding RNAs that play vital functions in the development of colorectal cancer (CRC). Subjects and Methods: The expression level of HOTAIR and H19 in the sera samples of Egyptian CRC patients along with normal controls was evaluated by quantitative real-time PCR. The possible correlations with the biochemical and clinicopathological characteristics were determined. Results: The expression of HOTAIR and H19 showed 7.55- and 11.38-fold increased levels, respectively, in CRC patients compared to the controls (p < 0.001). Furthermore, HOTAIR expression in CRC patients with regional lymph node metastasis was significantly higher when compared with CRC patients without regional lymph node metastasis (p = 0.034). HOTAIR and H19 expression showed no significant correlation with tumor site or carcinoembryonic antigen concentration. The sensitivity and specificity of HOTAIR and H19 in the detection of CRC cases were calculated as 92.9% and 100%, respectively. Conclusion: HOTAIR and H19 expression levels are upregulated in Egyptian CRC patients, and therefore can be considered noninvasive diagnostic biomarkers with high sensitivity and specificity.

Cysteine-assisted photoelectrochemical immunoassay for the carcinoembryonic antigen by using an ITO electrode modified with C3N4-BiOCl semiconductor and CuO nanoparticles as antibody labels.

A sensitive photoelectrochemical (PEC) immunoassay for the carcinoembryonic antigen (CEA) is described that is based on the use of C3N4-BiOCl semiconductor on an ITO electrode. The photocurrent of the modified electrode was measured under visible light illumination. It increased in presence of L-cysteine due to rapid separation of the photoexcited electrons and holes. A sandwich-type immunoassay in a 96-well microtiter plate format used CuO nanoparticles as label for the secondary antibody. The Cu2+ is released from the CuO in the sandwich complex by treatment with acid. The free Cu2+ combined with both the cysteine and the electron receptors of C3N4 and BiOCl. Under optimal conditions, this dual action immensely decreases the photocurrent of the PEC system, and the response is inversely proportional to the CEA concentrations from 0.1pgmL-1 to 10ngmL-1 at the working voltage of 0V (vs. SCE). The detection limit is 0.1pgmL-1,and the method is exhibited satisfactory selective, repeatable and stable. Graphical abstract Schematic representation of an immunoassay based on cysteine-assisted C3N4-BiOCl photoelectrochemical platform. CuO nanoparticles were utilized as labels in immunocomplex to release Cu2+ in acidic condition. Carcinoembryonic antigen in sample was detected sensitively by dual function of Cu2+ with cysteine and C3N4-BiOCl semiconductor.

Electrochemical immunosensor based on MoS2 NFs/Au@AgPt YNCs as signal amplification label for sensitive detection of CEA

Medically, the dynamic change of carcinoembryonic antigen (CEA) concentration has been an important indicator for monitoring and diagnosing tumors. The sensitive and early detection of CEA plays a momentous role in the prevention and diagnosis of cancer and the evaluation of treatment efficiency. In this work, a sensitive sandwich-type electrochemical immunosensor was fabricated for the quantitative detection of CEA. The trimetallic yolk-shell Au@AgPt nanocubes (Au@AgPt YNCs) loaded on amino-functionalized MoS2 nanoflowers (MoS2 NFs/Au@AgPt YNCs) were used as the labels to conjugate with secondary antibodies. The Au@AgPt YNCs with internal space and permeable shell improved catalytic active surface area. The nanosheet-based MoS2 NFs with good catalytic activity were used as carriers to load Au@AgPt YNCs effectively. Due to the biphasic synergistic catalysis, MoS2 NFs/Au@AgPt YNCs catalyzed the reduction of H2O2 effectually to amplify the current signal. Besides, Au triangular nanoprisms (Au TNPs) were used as substrate material to increase the effective contact areas with the surface of electrode and accelerate the interface electron transfer. Under the optimal conditions, a broad linear range from 10 fg mL−1 to 100 ng mL−1 with low detection limit of 3.09 fg mL−1 (S/N = 3) for detecting CEA was obtained. Moreover, the detection results of the human serum samples were satisfactory, indicating the fabricated immunosensor had potential application values in the early clinical analysis.

Development of an Immunosensor Based on the Exothermic Reaction between H2O and CaO Using a Common Thermometer as Readout.

Thermometers, one of the most commonly used instruments at home, are normally adapted to measure temperature directly with high accuracy but rarely adopted to act as readout in the biosensors. It is necessary to find some ways to establish a relationship between the concentration of the target and the temperature change. In this study, a common thermometer was used as readout to develop a convenient immunosensor. The designed immunosensor comprises three components, including target recognition area, water flow system, and exothermic reaction bottle. The capture antibody for the target [carcinoembryonic antigen (CEA) was selected as a model target] was preloaded on the bottom of the recognition area. In the presence of CEA, a sandwich-type structure was formed between the capture antibody, CEA, and biotinylated detection antibody. Then, the streptavidin-functionalized platinum nanoparticles were labeled on the detection antibody due to biotin-avidin interaction. The captured platinum nanoparticles can effectively catalyze the decomposition of H2O2 into O2. The continuous production of gas resulted in pressure increment inside the reaction bottle and further pushed the water flow into the exothermic reaction bottle. Finally, the water reacted with calcium oxide to generate a large amount of heat in the exothermic reaction bottle; thereby the temperature inside the bottle was enhanced and recorded by a common thermometer easily. The temperature enhancement has a linear relationship with the CEA concentration in the range of 7.81-500 pg/mL with a detection limit of 0.6 pg/mL. Furthermore, by taking advantage of simplicity, compatibility, stability, and high sensitivity, our temperature-based immunoassay has been applied to detect CEA in human serum samples with satisfactory results.

Predictive value of serum CEA level combined with PET/CT metabolic parameters MTV and TLG in primary liver metastases from colorectal cancer

Objective To analyze the predictive value of serum carcinoembryonic antigen(CEA) level combined with primary PET/CT metabolic parameters, metabolic tumor volume(MTV) and total glycolysis(TLG) in liver metastasis of colorectal cancer. Methods The clinical data of 86 patients with colorectal cancer who underwent PET/CT examination in the People's Hospital of Zhejiang Province from January 2013 to December 2017 were retrospectively analyzed.Univariate and multivariate logistic regression was used to analyze the relationship between clinicopathological parameters, MTV, TLG and liver metastasis. Results Of the 86 patients, there were 17 cases(19.77%) of liver metastases.Univariate analysis showed that there were significant differences in T stage(χ2=8.83), tumor location(χ2=5.43) and serum CEA content(t=11.65) between the liver metastasis group and the non-liver metastasis group(all P<0.05). The levels of TLG[(101.94±20.14)g] and MTV[(14.09±3.25)cm3] in the liver metastasis group were significantly lower than those in the non-liver metastasis group[(135.95±22.63)g, (25.09±4.33)cm3](t=5.66, 9.80, all P<0.01). Multivariate logistic regression analysis showed that T stage(OR=3.56, 95%CI: 1.06-12.00), tumor location(OR=1.38, 95% CI: 1.05-1.81), TLG(OR=1.68, 95% CI: 1.11-2.54), MTV(OR=3.86, 95% CI: 1.63-9.14) and serum CEA(OR=2.95, 95% CI: 1.60-5.41) were the influencing factors of liver metastases in patients with colorectal cancer(all P<0.05). Conclusion T stage, tumor location, primary PET/CT metabolic parameters(TLG, MTV) and serum CEA levels are the influencing factors of liver metastasis in patients with colorectal cancer, suggesting that the detection of serum CEA level combined with primary PET/CT metabolic parameters has certain predictive value for liver metastasis of colorectal cancer. Key words: Colorectal cancer; Liver metastasis; Positron emission computed tomography; Carcinoembryonic antigen; Metabolic tumor volume; Total glycolysis; Multivariate analysis; Influencing factor

Electrochemical sandwich aptasensor for the carcinoembryonic antigen using graphene quantum dots, gold nanoparticles and nitrogen doped graphene modified electrode and exploiting the peroxidase-mimicking activity of a G-quadruplex DNAzyme.

A sandwich-type electrochemical aptasensor has been constructed and applied for sensitive and selective detection of the carcinoembryonic antigen (CEA). The surface of a glassy carbon electrode (GCE) was first modified with nitrogen-doped graphene and then gold nanoparticles and graphene quantum dots electrodeposited on it to obtain an architecture of type GQD/AuNP/NG/GCE. In the next step, the CEA-binding aptamer was immobilized on the modified GCE. Hemin intercalates in the amino-modified hemin aptamer to form a hemin-G-quadruplex (hemin-G4) DNAzyme. The amino modified CEA aptamer II is connected to hemin-G4 by glutaraldehyde (GA) as a linker to produce CEAaptamerII/GA/hemin-G4 (=ApII/GA/DNAzyme). Through a sandwich mode, the ApII/GA/DNAzyme bioconjugates are captured on the modified GCE. Subsequently, the hemin-G4 acts as peroxidase-mimicking DNAzyme and rapidly catalyzes the electroreduction of hydrogen peroxide. The quantitative determination of CEA was achieved by differential pulse voltammetry, best at a working potential of around -0.27V vs. Ag/AgCl. Under optimized conditions, the assay has a linear response in the 10.0fgmL-1 to 200.0ngmL-1 CEA concentration range and a lower detection limit of 3.2fgmL-1. Graphical abstract Schematic presentation of a sandwich-type electrochemical aptasensor based on nitrogen doped graphene (NG), gold nanoparticles (AuNPs) and graphene quantum dots (GQDs) modified glassy carbon electrode, and thehemin-G4 DNAzyme for femtomolar detection of thecarcinoembryonic antigen.

Retrospective study of pleural parasitic infestations: a practical diagnostic approach

BackgroundPleural parasitic infestation (PPI) is a disease prevalent in certain parts of the world. It is frequently misdiagnosed due to its lack of standardized diagnostic criteria. The purpose of this study was to evaluate the clinical characteristics of PPI patients and develop a practical diagnostic approach for PPI.MethodsA retrospective study was conducted by reviewing the medical records of 11 patients with PPI. A practical diagnostic approach was proposed based on the unique laboratory findings.ResultsAll patients demonstrated respiratory symptoms, including shortness of breath, cough, fever, chest pain, excessive sputum and hemoptysis. Leukocytosis (> 10,000/μL) and eosinophilia (> 500/μL) of peripheral blood were present in 45.5 and 36.4% patients, respectively. The mean concentrations of pleural effusion lactate dehydrogenase (LDH), adenosine deaminase (ADA), protein and carcinoembryonic antigen (CEA) were 338.2 U/L (range, 61–667 U/L), 11.6 U/L (range, 0.1–28.2 U/L), 43.7 g/dL (range, 21.9–88.1 g/dL), and 1.84 mg/mL (range, 0.28–4.8 mg/mL), respectively. The mean percentage of eosinophils in the pleural effusion was 19.5% (10.5–41%). Blood test was positive for parasite-specific IgG antibody in 9 patients, including 4 for Paragonimus westermani, 3 for Taenia solium, 1 for Clonorchis sinensis and 1 for Echinococcus granulosus. Eggs of Clonorchis sinensis were detected in the stool of two patients. Sparganum was found in the pleural effusion of one patient. Respiratory symptoms and abnormal appearances in pulmonary radiographic examination were disappeared in all patients who received anti-parasitic treatment.ConclusionsIn patients with unexplained pleural effusion, parasite-specific IgG antibody tests should be performed when pleural fluid testing shows eosinophilic pleural effusion. It is preferable to consider the diagnosis of PPI in clinical practice when serum parasite-specific IgG antibody test is positive.

A sandwich-type electrochemical aptasensor for the carcinoembryonic antigen via biocatalytic precipitation amplification and by using gold nanoparticle composites.

A sandwich-type electrochemical aptasensor is described for detecting the carcinoembryonic antigen (CEA) with high sensitivity and accuracy. Two kinds of nanomaterials are used. The first was obtained by modifying gold nanoparticles with reduced graphene oxide and hemin (Hemin-rGO-AuNPs). The second consists of horseradish peroxidase-modified organic-inorganic hybrid nanoflowers linked to gold nanoparticles to obtain an architecture of type HRP-Cu3(PO4)2-HNF-AuNPs). These serve as carriers for two aptamers (apt1 and apt2) against CEA. Simultaneously, they were used to catalyze the precipitation reaction between 4-chloro-1-naphthol(4-CN) and H2O2. A sandwich-type assay linked to enzyme inhibition amplification was established for electrochemical determination of CEA. Under optimal experimental conditions and by using differential pulse voltammetry, the response peak currents (best measured at -0.34V vs. Ag/AgCl) increases linearly with the logarithm of the CEA concentration in the range between 100fgmL-1 and 100ngmL-1. The detection limit is as low as 29fgmL-1. Graphical abstract Schematic representation of the sandwich-type electrochemical aptasensor based on signal inhibition amplification from biocatalytic precipitation reaction. (HRP-Cu3(PO4)2 hybrid nanoflowers: Horseradish Peroxidase-Cu3(PO4)2 hybrid nanoflowers; AuNPs: Gold Nanoparticles; Hemin-rGO-AuNPs: Hemin-Reduced Graphene Oxide-Gold Nanoparticles; BSA: Bovine Serum Albumin; CEA: Carcinoembryonic Antigen; CEAapt1: 5'-SH-(CH2)6-ATA CCA GCT TAT TCA ATT-3'; CEAapt2: 5'-NH2-(CH2)6-AGG GGG TGA AGG GAT ACC C-3'; GCE: Glassy carbon electrode; 4-CN: 4-Chloro-1-naphthol; DPV: Differential pulse voltammetry).

Efficacy of interventional therapy and effect on inflammatory factors in patients with gastric cancer after chemotherapy.

The clinical effect of interventional therapy on gastric cancer after chemotherapy and effect on inflammatory factors in peripheral blood serum of patients were investigated. A retrospective analysis of 429 patients with gastric cancer treated in Xiangyang No. 1 People's Hospital, Hubei University of Medicine from July 2008 to December 2014 was performed. Among them, 220 patients received interventional therapy after chemotherapy as the experimental group, and 209 patients received conventional therapy as the control group. Serum carcinoembryonic antigen (CEA), tumor markers CA19-9, interleukin-6 (IL-6), interleukin-8 (IL-8) and interleukin-10 (IL-10) levels were measured before and after chemotherapy. The correlation between the concentration of CEA and CA19-9 before and after treatment and the levels of IL-6, IL-8 and IL-10 were analyzed in the experimental group, and all patients were followed up for 3 years. There were no significant differences in CEA, CA19-9, IL-6, IL-8 and IL-10 between the two groups before chemotherapy (P>0.05). After treatment, the concentrations of CEA, CA19-9, IL-6, IL-8 and IL-10 in the experimental group were significantly lower than those in the control group before and after treatment (P<0.05). The clinical efficacy and adverse reactions of the experimental group were significantly better than those in the control group (P<0.05). Pearson's correlation analysis showed that the concentrations of CEA and CA19-9 in the serum of the experimental group before and after treatment were positively correlated with the levels of IL-6, IL-8 and IL-10 (P<0.05). The 3-year overall survival rate of the study group was significantly higher than that of the control group (P<0.05). Cox regression analysis showed that age, Borrmann classification, degree of differentiation, and history of Helicobacter pylori infection were independent prognostic factors for patients with gastric cancer. Compared with traditional treatment, interventional therapy can greatly improve the recovery of gastric cancer patients after chemotherapy, reduce the occurrence of complications and inflammation, and improve the survival rate of patients.

False-positive elevated CEA during colon cancer surveillance: a cholecystitis case report diagnosed by PET-CT scan

A 53-year-old man with previous history of sigmoid colon adenocarcinoma who had undergone surgical resection and adjuvant chemotherapy presented with slightly rising carcinoembryonic antigen (CEA), while anatomical imaging modalities were unremarkable. FDG PET-CT study did not identify residual tumoral disease; however, there were abnormalities in the gallbladder most likely suggestive of cholecystitis. Eight weeks after cholecystectomy, serum CEA concentration reached normal values. Final histopathology of the gallbladder was also consistent with acute on chronic cholecystitis.

Unrecognized Value of Carcinoembryonic Antigen in Recurrent Rectal and Sigmoid Colon Cancer: Case Series.

Carcinoembryonic antigen (CEA) surveillance is recommended in patients with colorectal cancer for detection of potentially resectable metastases. In patients with appropriate symptoms, a highly increased CEA concentration (> 5 times the upper limit of normal) is considered strongly suggestive of cancer. Despite the recognized value, the test is neither absolutely sensitive nor specific for recurrent cancer. Generally, a greater diagnostic value has been assigned to elevated CEA levels, most commonly greater than 5 ng/mL. Fluctuations within the established normal CEA range are not customarily analyzed. We report here on 11 patients (8 women, 3 men) who, during the postoperative follow-up period, received a diagnosis of recurrent cancer despite their CEA levels exhibiting very subtle increases. Our cohort shared several similar characteristics such as a nonsmoking status, younger age (median, 52 years at initial diagnosis), and exclusive localization of the cancer to the rectosigmoid region. This important clinical observation may expand a prognostic value of CEA in a certain category of patients with colorectal cancer.

Performance comparison of the methylated BCAT1/IKZF1 ctDNA test (COLVERA) with the CEA assay for detection of recurrent colorectal cancer.

3589 Background: Early detection of recurrent colorectal cancer (CRC) will improve treatment options, but the current standard blood test of carcinoembryonic-antigen (CEA) has suboptimal sensitivity for recurrence. This study compared performance of a quantitative circulating tumor DNA (ctDNA) assay for methylated BCAT1 and IKZF1 (COLVERA) with that of CEA. Methods: 301 patients were monitored for recurrence after clearance of primary CRC. Blood was collected at scheduled intervals and concentrations of CEA and ctDNA were measured using the LIAISON CEA test (Diasorin) and the COLVERA ctDNA test (Clinical Genomics). Surveillance for recurrent disease was examined using regular CT scans. Sensitivity of each blood test for recurrence was assessed in the sample collected closest to the time of imaging confirming recurrence status. Absence of recurrence was defined as at least two consecutive clear CT scans. Receiver operator characteristic (ROC) analyses were used to determine optimal positivity threshold for Colvera. Results: 131 patients underwent satisfactory assessment for recurrence and had blood testing performed within 12 months of determining recurrence status (61.8% male, mean age 62.6 ±.12.2(SD)y). Of the 47 recurrence cases, 37 (74%) were distant. The areas under the ROC curves were 0.7761 and 0.8188 for CEA and COLVERA, respectively (each p &lt; 0.001). An optimal cut-off of 12.8pg/sample was determined for COLVERA and the standard 5ng/mL cut-off was selected for CEA. COLVERA had a significantly higher sensitivity for detecting recurrence as compared to CEA (68.1% vs 31.9%, p &lt; 0.001) with a similar specificity (97.6% Vs 96.4%, p = 0.6547). A multivariate analysis determined COLVERA to be a predictor of recurrence independent of CEA with positive COLVERA samples being 66.4 times (95%CI 14.0-315.8) more likely to have recurrence confirmed within the study timeframe, whereas CEA was not a significant predictor of recurrence (p = 0.228). Conclusions: These findings indicate that COLVERA, reporting in quantitative mode, is a more sensitive test than CEA. It provides a viable alternative for sensitive and early detection of recurrent CRC. Clinical trial information: 12611000318987.

Photovoltaics, plasmonics, plastic antibodies and electrochromism combined for a novel generation of self-powered and self-signalled electrochemical biomimetic sensors

This work describes further developments into the self-powered and self-signalled biosensing system that merges photovoltaic cells, plastic antibodies and electrochromic cells into a single target. Herein, the plasmonic effect is introduced to improve the photoanode features of the photovoltaic cell, a dye sensitized solar cell (DSSC), and better electrocatalytic features are introduced in the electrode containing the sensing element.In brief, the DSSC had a counter-electrode of poly(3,4-ethylenedioxythiophene) on an FTO glass modified by a plastic antibody of 3,4-ethylenedioxythiophene and pyrrol. The photoanode had dye sensitized TiO2 modified with gold nanoparticles (AuNPs) to increase the cell efficiency, aiming to improve the sensitivity of the response of hybrid device for the target biomarker. The target biomarker was carcinoembryonic antigen (CEA). The response of the hybrid device evidenced a linear trend from 0.1 ng/mL to 10 μg/mL, with an anionic slope of 0.1431 per decade concentration. The response of the plastic antibody for CEA revealed great selectivity against other tumour markers (CA 15–3 or CA 125). The colour response of the electrochromic cell was also CEA concentration dependent and more sensitive when the hybrid device was set-up with a photoanode with AuNPs. A more intense blue colour was obtained when higher concentrations of CEA were present.Overall, this improved version of the self-powered and self-signalled set-up has zero-requirements and is particularly suitable for point-of-care analysis (POC). It is capable of screening CEA in real samples and differentiating clinical levels of interest. This concept opens new horizons into the current cancer screening approaches.

Use of cholesterol and soluble tumour markers CEA and syndecan-2 in pleural effusions in cases of inconclusive cytology

AimsIn order to improve diagnostics in pleural effusions, additional value of effusion cholesterol, carcinoembryonic antigen (CEA) and syndecan-2 assays to cytology was studied.MethodsBiomarkers were measured in effusion supernatants from 247...

A novel nitrogen and sulfur co-doped carbon dots-H2O2 chemiluminescence system for carcinoembryonic antigen detection using functional HRP-Au@Ag for signal amplification.

A novel nitrogen and sulfur co-doped carbon dots (NS-CDs)-H2O2 chemiluminescence (CL) system was developed to detect carcinoembryonic antigen (CEA) by taking advantage of dual-signal amplification of functional Au@Ag nanoparticles (NPs) nanoprobes. Horseradish peroxidase (HRP) and the complementary DNA were co-immobilized onto Au@Ag NPs surface to shape the functional nanoprobes (HRP-Au@Ag-cDNA) for signal amplification. In this proposal, HRP-Au@Ag-cDNA was specifically hybridized with CEA aptamer-functionalized magnetic beads to form the double-strand hybridization nanocomposites (HRP-Au@Ag-dsDNA-MB). Upon the addition of CEA, the CEA aptamer preferred to bind with CEA instead of double-strand hybridization interaction, thus HRP-Au@Ag-dsDNA-MB was dehybridized and the HRP-Au@Ag-cDNA nanoprobe was released. The synergistic catalytic effects of HRP and Au @Ag NPs endow the nanoprobe producing a dual CL signal amplification in the NS-CDs-H2O2 CL system. The CL intensity of the developed strategy enhanced with CEA concentration increasing in the range of 0.3-80 ng mL-1. Benefiting from the synergistic effect, a detection limit as low as 94 pg mL-1 was obtained. Moreover, successful application of this CL sensing platform was achieved for the determination of CEA in human serum samples, demonstrating the promising prospect in the early tumor warning and therapeutic monitoring.

Near-infrared carbon dots-based fluorescence turn on aptasensor for determination of carcinoembryonic antigen in pleural effusion

Early detection of carcinoembryonic antigen (CEA) is of great significance for the screening, diagnosis, monitoring and prognosis analysis of lung cancer. Herein, a novel fluorescence aptasensor with high signal-noise ratio (SNR) was constructed to achieve highly-sensitive detection of CEA relied upon the fluorescence resonance energy transfer (FRET) between near-infrared carbon dots (NIR-CDs) and gold nanorods (AuNRs). Initially, AuNRs@SiO2-Aptamer and NIR-CDs-DNA probe were prepared via the covalent bonding reaction between their corresponding carboxyl and amino groups, respectively. After DNA hybridization, the aptasensor was formed, meanwhile, the fluorescence of NIR-CDs was quenched by AuNRs@SiO2. Once CEA encountered the aptasensor, it would selectively combine with CEA aptamer to unwind the preformed DNA double-strand architecture thereby resulting in the NIR-CDs-DNA detach from the surface of AuNRs@SiO2. The attendant fluorescence recovery of NIR-CDs was linearly correlated with the concentration of CEA. According to this relationship, the NIR-CDs based “turn on” sensing system was constructed and exhibited prominent responses toward CEA in the concentration range of 0.1–5000 pg/mL and a relatively low detection limit (0.02 pg/mL). Moreover, it displayed high specificity against other biomarkers or proteins, good reproducibility and acceptable accuracy regarding human pleural effusion samples.

A dual amplification electrochemical immunosensor based on HRP-Au@Ag NPs for carcinoembryonic antigen detection

A sensitive sandwich-type electrochemical immunosensor based on dual amplification strategy was constructed. The dual amplification strategy has been used secondary antibody(Ab2)-horseradish peroxidase(HRP)-Au@Ag nanoparticles (Au@Ag NPs) for carcinoembryonic antigen(CEA) detection. Ab2-HRP-Au@Ag NPs as dual amplification markers triggered the disproportionation of H2O2, which could facilitate the catalytic oxidation of hydroquinone to quinone(BQ). In addition, due to their large surface area and excellent conductivity, nitrogen-doped graphene were used as a platform to firmly assemble primary antibody (Ab1). Above mentioned generated amout of BQ are corresponding to trace CEA, resulting in the highly electrochemical reduction signal. Under the optimal conditions, the linear range of CEA concentration was 0.0001–100 ng mL−1, and the limit of detection (LOD) could be as low as 0.05 pg mL−1. Importantly, the immunosensor also showed acceptable stability, reproducibility and selectivity.

Three dimensional sea-urchin-like PdAuCu nanocrystals/ferrocene-grafted-polylysine as an efficient probe to amplify the electrochemical signals for ultrasensitive immunoassay of carcinoembryonic antigen

A novel sandwich-like immunosensor was efficiently fabricated for detection of carcinoembryonic antigen (CEA) with three dimensional sea-urchin-like PdAuCu nanocrystals (PdAuCu NCs)/ferrocene-grafted-polylysine (Fc-g-PLL) as the label of secondary antibodies (Ab2) and Au nanoparticles (Au NPs) as the substrate material. Herein, PdAuCu NCs were directly synthesized with polyethylene oxide (PEO) as a growth-directing agent by a facile one-step aqueous method without any organic solvent. Meanwhile, Fc-g-PLL was obtained by covalent linkage of Fc with PLL via Schiff-base reaction. The well-dispersed PdAuCu NCs by Fc-g-PLL have the enlarged surface area, enhanced catalytic properties and superior biocompatibility to amplify the current signals. The resultant immunosensor shows linear relationship of the electrochemical responses with the CEA concentrations within a broader linear range (0.001–100.0 ng mL–1) and a lower detection limit (0.23 pg mL–1, S/N = 3). Furthermore, the immunosensor was explored for practical assay of CEA in human serum samples with accredited results. The novel immunoassay provides a feasible platform for early medical diagnosis.

The expressions and diagnostic values of miR-18a and miR-21 in esophageal cancer

Objective: To investigate the expressional levels and diagnostic values of miR-18a and miR-21 in esophageal carcinoma. Methods: The expressions of miR-18a and miR-21 in esophageal cancer tissues and adjacent tissues from 45 esophageal cancer patients, peripheral blood from 45 esophageal cancer patients and 50 healthy donors respectively were detected by RT-PCR. The expressions of miR-18a and miR-21 in normal esophageal epithelial cell HET-1A, esophageal cancer cell lines including ECA109, KYSE150 and TE1 were also detected. Chemiluminescence immunoassay was used to quantitatively detect the concentrations of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), CYRFA21-1 and TPA (tissue polypeptide antigen) in peripheral blood serum from esophageal cancer patients and healthy controls. Meanwhile, the diagnostic effects of miR-18a and miR-21 on esophageal cancer were compared with those of tumor markers in serum. Results: The expression levels of miR-18a and miR-21 in esophageal cancer cells ECA109, KYSE150 and TE1 were 1.64±0.17, 1.62±0.19, 1.46±0.12 and 20.52±1.48, 6.73±0.73, 1.43±0.19, respectively, higher than those in normal esophageal epithelial cells (both P<0.01). The expressions of miR-18a and miR-21 in esophageal cancer tissues were 32.48±28.62 and 8.67±11.98, respectively, significantly higher than those in adjacent tissues (all P<0.001). The expression levels of miR-18a and miR-21 in peripheral blood of patients with esophageal cancer were 12.66±11.92 and 9.15±8.14, respectively, significantly higher than those in the normal control group (both P<0.001). The receiver operating characteristic (ROC) curve analysis showed that the area under the curve of miR-18a and miR-21 for diagnosis of esophageal cancer were 0.948 and 0.913 5, respectively. Compared with traditional esophageal tumor markers, the expressions of miR-18a and miR-21 were more sensitive in the diagnosis of esophageal cancer. The sensitivity and accuracy of the expressions of miR-18a and miR-21 combined with traditional esophageal tumor markers in diagnosis of esophageal cancer can be further improved to 97.8% and 68.4%, respectively. Conclusion: Our study reveals that the expressions of miR-18a and miR-21 play important roles in the diagnosis of esophageal cancer and may be potentially novel biomarkers.