A Novel Electrochemical Immunosensor Based on DNA/Fe3O4 (Core) /ZrO2(Shell)one Dimension Magnetic Probes for Carcino-Embryonic Antigen

2011 ◽  
Vol 80-81 ◽  
pp. 200-206 ◽  
Author(s):  
Fu Tao Hu ◽  
Yuan Zao Wu ◽  
Yu Ting Cao ◽  
Ning Gan

A novel and sensitive electrochemical enzyme-linked immunosorbent assay (ELISA) system of Hydroquinones (HQ)- peroxide hydantoin (CP) -horseradish-peroxidase (HRP) by using magnetic DNA linked core-shell Fe3O4@ZrO2(ZMPs)nanoparticles as labels and signal amplification was established. In the presence of carcinoembryonic antigen (CEA) analyte, the sandwich-type immunocomplex could be formed between HRP labeled CEA second antibody(CEA Ab2) modified DNA-ZMPs probes (DNA / (ZMPs-HRP-CEA Ab2) n) and nano-gold CEA modified glassy carbon electrode (GCE | CEA Ab1) as an immune electrode.The concentration of CEA was determined based on the current signal, which was generated in the reaction between HQ and CP catalyzed by HRP on the sandwich-type immunocomplex. ZMPs nanoparticles as label material can not only perform the rapid separation and purification of signal antibody on magnetic field, but also immensely enhance the labeled capacity of HRP-anti-CEA which can amplify the catalytic current signal. Furthermore, the electrode modification process was not required. The method provided a linear response range between 0.01 and 200 ng·mL-1with a detection limit of 4 pg·mL-1.Moreover, the proposed electrochemical ELISA method exhibited good precision, high sensitivity and acceptable reproducibility, and could be further developed for clinical detections of CEA and other biomarkers.

2011 ◽  
Vol 343-344 ◽  
pp. 1207-1211 ◽  
Author(s):  
Qi Zhi Diao ◽  
Yuan Li ◽  
Mi Zhou ◽  
Guo Ming Xie

A new electrochemical immunosensor for serum myeloperoxidase (MPO) has been developed based on the self-assembly multilays of multi-walled carbon nanotubes (MWNTs), thionine (THI), gold nanoparticles (GNPs) and chitosanon (CHIT) on the glassy carbon electrode (GCE). The antibody of MPO (anti-MPO) was absorbed on the surface of GNPs monolayer. Horseradish peroxidase (HRP) was employed to block non-specific binding and amplify the response current signal. It was observed that the peak current was linear with the MPO concentration in a range of 2.5-125 µgl-1. The detection limit was 1.425 µgl-1 (S/N=3). Correlation analysis showed that this new immunosensor assay has a significant correlation with enzyme-linked immunosorbent assay (ELISA) (r=0.96, p>0.05) for 40 clinical specimens.


2020 ◽  
Vol 28 ◽  
Author(s):  
Hayati Filik ◽  
Asiye Aslıhan Avan ◽  
Mustafa Özyürek

: The prostate-specific antigen (PSA) has been considered a crucial serological marker for distinguishing prostate based cancer. This surveys recent progress in the construction of nanomaterial-based electrochemical immunosensors for a PSA. This review (from 2015 to 2020) reports the latest progress in PSA sensing based on the employ of different types of nanostructured materials. The most popular used nanostructured materials are metal, metal oxide, carbon-based nanomaterials, and their hybrid architectures utilized for distinct amplification protocols. In this review, the electrochemical immunosensors for prostate-specific antigen sensing are classified into three categories such as sandwich type@labeled, label free@nonlabeled and aptamer-based electrochemical immunosensor.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3926 ◽  
Author(s):  
Umi Mohd Azmi ◽  
Nor Yusof ◽  
Norzila Kusnin ◽  
Jaafar Abdullah ◽  
Siti Suraiya ◽  
...  

A rapid and sensitive sandwich electrochemical immunosensor was developed based on the fabrication of the graphene/polyaniline (GP/PANI) nanocomposite onto screen-printed gold electrode (SPGE) for detection of tuberculosis biomarker 10-kDa culture filtrate protein (CFP10). The prepared GP/PANI nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The chemical bonding and morphology of GP/PANI-modified SPGE were studied by Raman spectroscopy and FESEM coupled with energy dispersive X-ray spectroscopy, respectively. From both studies, it clearly showed that GP/PANI was successfully coated onto SPGE through drop cast technique. Cyclic voltammetry was used to study the electrochemical properties of the modified electrode. The effective surface area for GP/PANI-modified SPGE was enhanced about five times compared with bare SPGE. Differential pulse voltammetry was used to detect the CFP10 antigen. The GP/PANI-modified SPGE that was fortified with sandwich type immunosensor exhibited a wide linear range (20–100 ng/mL) with a low detection limit of 15 ng/mL. This proposed electrochemical immunosensor is sensitive, low sample volume, rapid and disposable, which is suitable for tuberculosis detection in real samples.


2020 ◽  
Author(s):  
Hye In Ahn ◽  
Ji-Won Park ◽  
Hyun-Jae Jang ◽  
Ok-kyoung Kwon ◽  
Jung Hee Kim ◽  
...  

Abstract Background: The type three secretion system (T3SS) is a major virulence system of Pseudomonas aeruginosa (P. aeruginosa). The effector protein Exotoxin S (ExoS) produced by P. aeruginosa is secreted into the host cells via the T3SS. For the purpose of screening the inhibitors with regard to ExoS secretion, we developed the sandwich-type enzyme-linked immunosorbent assay (ELISA) system. From the initial screening, quercetin was selected because it has the prominent effect of ExoS inhibition and also is known to have anti-inflammatory and antioxidant effects on mammalian cells.Results: In this study, we investigated the effects of quercetin on the expression and secretion of ExoS using the ELISA and Western blot analysis methods. The results showed that the secretion of ExoS was significantly decreased by 10, 20uM quercetin. Also, pscF and popD, which are composed of the T3SS needle, are reduced by quercetin at the mRNA level, and we confirmed the inhibitory effect of quercetin on cytokines in P. aeruginosa-infected H292 cells by real-time polymerase chain reaction (PCR). Conclusion: Collectively, quercetin inhibits the secretion of ExoS by reducing both ExoS production and the expression of the needle protein of T3SS. Furthermore, these results suggest that quercetin has the potential to be used as an anti-toxic treatment for the disease caused by P. aeruginosa infection.


1991 ◽  
Vol 37 (10) ◽  
pp. 1742-1745 ◽  
Author(s):  
R Saïle ◽  
A Kandoussi ◽  
M Deveaux ◽  
J Descamps ◽  
E Hachulla ◽  
...  

Abstract This enzyme-linked immunosorbent assay procedure for quantifying serum amyloid P (SAP) in human plasma makes use of affinity-purified polyclonal antibodies to SAP in a "sandwich"-type format. The procedure is sensitive, reproducible, simple, and easily automatable. Results correlate well with those by a rocket immunoelectrophoresis method performed with the same antibodies. Sera from apparently normal individuals had a mean SAP content of 44.17 mg/L and increased with age.


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