A highly sensitive and selective label-free impedimetric immunosensor for the detection of interleukin-6 based on AuNPs@pDA@NiCo(2)S(4)@MoS(2) nanocomposite.

A highly sensitive and selective label-free impedimetric immunosensor based on AuNPs@pDA@NiCo2S4@MoS2 nanocomposite modified on the surface of a screen-printed electrode (SPE) was designed for the detection of interleukin-6 (IL-6). The distribution of NiCo2S4 nanoparticles on MoS2 nanosheets was able to prevent them from agglomerating. The polydopamine (pDA) layer was coated on the surface of NiCo2S4@MoS2 nanosheets by self-polymerization, which improved the stability and biocompatibility of the nanomaterial. The excellent reduction ability of pDA promoted the synthesis of gold nanoparticles (AuNPs), which increased the amount of antibody adsorption and the conductivity of the material. Finally, the antibody (Ab) of IL-6 was immobilized on the surface of AuNPs@pDA@NiCo2S4@MoS2 nanocomposite. Electrochemical impedance spectroscopy (EIS) was used to detect the change of impedance before and after the immune response between Ab and IL-6 antigen (IL-6). Under the optimal experimental conditions, the relative change in impedance and the logarithmic concentration of IL-6 showed a good linear relationship in the range 1.00 to 1.00 × 106 pg/mL, with a low detection limit of 0.97 pg/mL. In addition, the proposed immunosensor performed with good reproducibility, stability, and specificity. It was successfully applied to the determination of IL-6 in patient's serum samples of head and neck carcinoma with recoveries of 98.40% to 106.5%. To sum up, the proposed label-free impedimetric immunosensor was successfully constructed for IL-6 detection in real samples.

Wang Y ，Zhang J ，Lv X ，Ding Y ，Wang Y ，Liu Y ，Wu C ，Yang G ... -  《-》

Prussian blue-doped CaCO(3) nanoparticle-labeled secondary antibodies for electrochemical immunoassay of interleukin-6 with migraine patients.

Chen Z ，He W ，Lin R ，Wu D ，Jiang X ，Cheng Y ... -  《-》

Functionalized Triangular Carbon Quantum Dot Stabilized Gold Nanoparticles Decorated Boron Nitride Nanosheets Interfaced for Electrochemical Detection of Cardiac Troponin T.

Kim SE ，Yoon JC ，Muthurasu A ，Kim HY ... -  《-》

A simple electrochemical immunosensor based on MWCNTs-COOH/Fc-COOH@CoAl-LDH, nanocomposite for sensitive detection of the tumor marker CA724.

A novel label-free electrochemical immunosensor for the ultrasensitive determination of cancer antigen (CA724) was developed using a novel composite of CoAl layered double hydroxides (CoAl-LDH) and carboxyl-functionalized multiwall carbon nanotubes (MWCNTs-COOH) as platform and ferrocenecarboxylic acid (Fc-COOH) as signal label. The MWCNTs-COOH/Fc-COOH@CoAl-LDH composite was prepared by a convenient and simple one-step ultrasonic method, and various characterization techniques consisting of scanning electron microscopy (SEM), transimission electronic microscopy (TEM), TEM-Mapping, fourier transform infrared (FT-IR), X-ray diffraction (XRD) and X-ray photoelectronic energy spectrum (XPS) were applied to study the size and morphological features. Due to its large specific surface area and multilayer structure, the CoAl-LDH can be post-doped to embed a large amount of signal probe to realize the amplification of the internal reference signal Fc. In addition, the higher conductivity of MWCNTs-COOH compensates for the deficiency of CoAl-LDH, which effectively strengthened the electron transfer efficiency of electrochemical signaling substances. The optimal experimental conditions were detected to be 2.5 mmol of Fc-COOH, 4.0 mg/mL of concentration, pH 6.0, incubation time of 40 min, and incubation temperature of 37 ℃. Under optimal conditions, the fabricated sensor exhibits linearity in a wide dynamic range covering the physiological concentration, from 0.001 to 100 U/mL and the limit of detection (LOD) was 0.03962 mU/mL, the calibration equation is stated as △I = 7.76363 log10CCA724 + 40.50351 (R2 = 0.99674). The sensor is successfully detects trace levels of CA724 in human serum with excellent recovery rates ranging from 100.52 %-102.30 %, proving the synergy of MWCNTs-COOH/Fc-COOH@CoAl-LDH as a promising platform for electrochemical sensing for clinical detection of other disease markers.

Miao M ，Zhang R ，Gao H ，Zhang H ，Que L ，Gu X ，Chang D ，Pan H ... -  《-》

Label-free differential chemiluminescent immunosensor based on magnetic nanoparticles CuFe(2)O(4)@ABEI-GNPs with dual catalytic sites.

Cancer has become one of the main causes of death globally. The level of tumor markers in serum is correlated with the occurrence of cancer. Carcinoembryonic antigen (CEA) is the most commonly utilized tumor marker for cancer detection. Recently, various analytical technologies have been reported to detect biomarkers. However, developing a simple, sensitive, and noninvasive approach for CEA detection remains challenging in cancer diagnosis. Consequently, there is an urgent need for researchers to carry out innovative approaches for CEA detection. In this work, copper ferrite nanoparticles (CuFe2O4 NPs) with excellent dispersity and fascinating magnetism have been successfully synthesized. To get CuFe2O4@ABEI-GNPs, ABEI-gold NPs (ABEI-GNPs) were generated on the surface of CuFe2O4 NPs by using N-(4-Aminobutyl)-N-ethylisoluminol (ABEI) as a mild reduction reagent to reduce chloroauric acid tetrahydrate (HAuCl4·4H2O). The CuFe2O4@ABEI-GNPs exhibited a superior chemiluminescence (CL) performance compared with CuFe2O4@ABEI NPs, which was attributed to the synergistic catalysis effects of CuFe2O4 NPs and GNPs. Interestingly, two unique CL emission peaks were observed in the kinetic curve of CuFe2O4@ABEI-GNPs. Furthermore, it was found that the kinetic curve could be regulated by the pH of hydrogen peroxide (H2O2) and a possible CL mechanism was proposed. Owing to the favorable CL properties of CuFe2O4@ABEI-GNPs, a label-free differential immunosensor was fabricated for CEA monitoring using the intensity difference between CL-1 and CL-2. The developed immunosensor exhibited a wide linear range from 0.1 to 5000 pg/mL, and a low detection limit of 0.05 pg/mL. The immunosensor was capable of determining CEA in real samples with simple operation, high accuracy, and good sensitivity. This study introduces a novel approach for developing CL functionalized materials, which have broad application potential in bioassays. The proposed differential method could serve as a novel tool for determining CEA in the diagnosis of clinical cancer.

Ren Y ，Zhou B ，Yu M ，Xue Y ，Kong W ，Yang R ... -  《-》