Dual defected g-C 3 N 4 Faraday cage-type electrochemiluminescence immunosensor for ultrasensitive " turn on " detection of carcinoembryonic antigen

Self-reinforced D-MOF and autocatalytic AuPd@SnS2 dual-wavelength electrochemiluminescence biosensor for detection of ctDNA and CEA

A label-free ECL aptasensor for sensitive detection of carcinoembryonic antigen based on CdS QDs@MOF and TEOA@Au as bi-coreactants of Ru(bpy)32+

Ultrasensitive immunosensor for multiplex detection of cancer biomarkers carcinoembryonic antigen (CEA) and yamaguchi sarcoma viral oncogene homolog 1 (YES1) based on eco-friendly synthesized gold nanoparticles

Hydrogel-integrated multimodal biosensor for the detection of glucose and carcinoembryonic antigen

An ultrasensitive electrochemiluminescence (ECL) immunosensor for the detection of carcinoembryonic antigen (CEA) in serum and saliva was developed. Ru(bpy)32+-graphene-Nafion composite was first coated on the glassy carbon electrode surface in this ECL immunosensor. The sandwich-type immunoreactions between the first antibody and the second antibody bridged the donors Ru(bpy)32+ and acceptors QDs, which led to the occurrence of ECL quenching of Ru(bpy)32+ by QDs. Based on the efficient ECL quenching, ultrasensitive CEA detection was realized. Under optimal conditions, the ECL signal depended linearly on the logarithm of the CEA concentration within a range from 0.005 to 0.5 pg/mL, and the detection limit of CEA was 0.002 pg/mL. Moreover, the proposed ECL immunosensor provides a stable, specific, and highly sensitive immunoassay protocol for CEA detection at very low levels, which might hold a promise for clinical application.

Comparable analysis of six immunoassays for carcinoembryonic antigen detection

A novel electrochemiluminescence (ECL) biosensor based on enzyme-aided multiple amplification and a deoxyribozyme-driven DNA walker was designed to achieve highly sensitive detection of carcinoembryonic antigen (CEA). When the present target CEA was combined with the aptamer, the trigeminal DNA structure was formed with the use of primers and templates, and polymerization amplification reactions were carried out with the assistance of enzymes, generating a large number of product chains (DNA walker) with the DNAzyme sequence. Then, the DNA walker hybridized with the DNA-CdSe quantum dot (QD) signal probe on the electrode surface, and the Pb2+ ion-assisted DNAzyme enabled the DNA signal probes to be cyclically clipped, resulting in a significant decrease in the QD ECL signal for the sensitive detection of CEA. The change value of the ECL signal is linearly related to the logarithm of CEA concentration in the range from 1.0 fg/mL to 100 ng/mL, and the detection limit is 0.21 fg/mL. This DNAzyme-driven DNA walker can be used to design versatile biosensors to achieve “signal-off” or “signal-on” detection by shearing many kinds of signal or quenching probes. Thus, this research provides a new promising strategy for the CEA assay and is expected to be used in the early diagnosis of tumours.

Gold nanoring core-shell satellites with abundant built-in hotspots and great analyte penetration: An immunoassay platform for the SERS/fluorescence-based detection of carcinoembryonic antigen

Dual quenching ECL strategy based on AgInZnS quantum dots and a new co-reaction promoter oxygen vacancy-modified P5AIn/TiO2 for sensitive CEA detection

Fiber optic sensors have been widely applied to address issues such as cardiovascular diseases, pathogen detection, and cancer biomarker detection. In this work, an ultra-low limit of detection, high-specificity, and label-free optical fiber biosensor for the detection of carcinoembryonic antigen (CEA) was proposed and experimentally demonstrated. A microfiber interferometer with refractive index sensitivity of up to 1915.955 nm/RIU was employed as the sensor head. The sensitivity of the sensor was further enhanced by the incorporation of molybdenum disulfide (MoS2), which facilitated the immobilization of CEA antibodies as specific detection markers on the microfiber surface. Experimental results showed that the proposed sensor achieved a detection limit of 15.86 fg/mL. The sensitivity of the biosensor was 4.727 nm/log(mg/mL). Notably, this biosensor demonstrated excellent specificity and label-free operation and enabled the detection of low-concentration CEA in approximately 15 minutes. The proposed micro fiber CEA sensor provided a highly sensitive and low-cost method for the early diagnosis of cancer.

Early diagnosis of cancer demands sensitive and accurate detection of cancer biomarkers in blood. Carbon dots (CDs) bio-functionalization with antibodies, peptides or aptamers have played significant role in cancer diagnosis and targeted cancer therapy. Herein, a biosensor for detection of cancer biomarker carcinoembryonic antigen (CEA) in blood serum has been designed using CDs bio-functionalized with HRP-conjugated CEA antibody (CUCDs@CEAAb2) as detection probe. CDs were synthesized by upscaling of cow urine, a nitrogen rich biomass waste, by hydrothermal method. Detection probe based on CDs resulted in 3.5 times higher sensitivity as compared to conventional electrochemical sandwich immunoassay. To further improve the sensor performance, hyper-branched polyethylenimine grafted poly amino aniline (PEI-g-PAANI) was used as the sensing interface, which enabled immobilization of higher amount of capture antibody. Detection of CEA in human blood serum coupled with wide linear range (0.5–50 ng/ml), good specificity, stability, reproducibility and low detection limit (10 pg/ml) signified the excellence of CUCDs based CEA immunosensor. CUCDs exhibited excitation wavelength dependent fluorescence property and showed strong blue emission under UV irradiation. MTT assay indicated that the material is not toxic towards human dental pulp stem cells (hDPSCs) and MG63 osteosarcoma cells (cell viability > 90%). The present study demonstrates a methodology for valorization of animal waste to a cost-effective carbon based functional nanomaterial for clinical detection of cancer biomarkers.

To evaluate the association of a diagnosis of lung cancer and combined detection of serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), neuron specific enolase (NSE) as well as the cytokeratin 19 fragment (CYFRA21-1). Serum CEA, CA19-9, NSE and CYFRA21-1 were assessed in 150 patients with lung cancer, 100 patients with benign lung disease and 100 normal control subjects, and differences of expression were compared in each group, and joint effects of these tumor markers in the diagnosis of lung cancer were analyzed. Serum CEA, CA19-9, NSE and CYFRA21-1 in patients with lung cancer were significantly higher than those with benign lung disease and normal controls (p<0.01). It is suggested that these four tumor markers combined together could produce a positive detection rate of 90.2%, significantly higher than that of any single test. Combination detection of CEA, CA19-9, NSE and CYFRA21-1 could significantly improve the sensitivity and specificity in diagnosis of lung cancer, and could be important in early detection.

We developed a signal-on electrochemiluminescence (ECL) aptasensor by using SI-ATRP to facilitate high-density immobilization of luminophores and manganese dioxide–graphene (MnO2–GO) composite to indirect deactivate the excited state of Ru(dcbpy)32+ for ultrasensitive detection of carcinoembryonic antigen (CEA). In this approach, manganese dioxide–graphene (MnO2–GO) composite served as an efficient quencher for indirect deactivating the excited state of Ru(dcbpy)32+. Surface initiated atom transfer radical polymerization (SI-ATRP) was applied to functionalize multiwalled carbon nanotubes (MWNTs) with glycidyl methacrylate (GMA) as the functional monomer. A nanocomposite material of polyamidoamine (PAMAM) dendrimer encapsulated AuNPs was used as the carrier to combine Ru(dcbpy)32+ and poly-GMA together for the synthesis of the ECL matrices. The prepared matrices were applied to bind amino-modified auxiliary probe I (A1), which was partially complementary with the CEA aptamer. Meanwhile, the MnO2–GO composite was modified with another amino-modified CEA aptamer-partial-complementary auxiliary probe II (A2). Through the hybridization of CEA aptamer with A1 and A2, the quencher MnO2–GO composite was linked with the ECL matrices, by which a low ECL signal was detected (off-state). However, in the presence of CEA, the sandwich-like structure was destroyed because CEA would bind to its aptamer in lieu of the auxiliary probes, which resulted in a recovery of ECL signal (on-state). The proposed ECL aptasensor showed high sensitivity with a detection limit of 25.3 fg mL−1 and a wide linear range of 0.1 pg mL−1 to 20 ng mL−1. Consequently, with the excellent sensitivity, stability and satisfying precision, the as-proposed strategy constitutes a promising detection technique for clinical diagnosis.

Fabrication of sensitive bioelectrode based on atomically thin CVD grown graphene for cancer biomarker detection

The development of simple and probe-integrated aptamer sensors for the electrochemical detection of tumor biomarkers is of great significance for the diagnosis of tumors and evaluation of prognosis. In this work, a probe-integrated aptamer sensor is demonstrated based on the stable confinement of an electrochemical probe in a bipolar nanochannel film, which can realize the reagentless electrochemical detection of the tumor biomarker carcinoembryonic antigen (CEA). To realize the stable immobilization of a large amount of the cationic electrochemical probe methylene blue (MB), a two-layer silica nanochannel array (SNF) with asymmetric charge was grown on the supporting electrode from bipolar SNF (bp-SNF). The inner SNF is negatively charged (n-SNF), and the outer-layer SNF is positively charged (p-SNF). The dual electrostatic interaction including the electrostatic adsorption from n-SNF and the electrostatic repulsion from p-SNF achieve the stable confinement of MB in bp-SNF. The recognitive interface is fabricated by the covalent immobilization of the CEA aptamer on the outer surface of bp-SNF, followed by the blocking of non-specific binding sites. Owing to the stable and abundant immobilized probes and highly specific aptamer interface, the developed aptamer sensor enables the sensitive detection of CEA in the range of 1 pg/mL to 1 μg/mL with a low limit of detection (LOD, 0.22 pg/mL, S/N = 3). Owing to the high selectivity and stability of the developed biosensor, reagentless electrochemical detection of CEA in serum was realized.