Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Sandwich-Type Electrochemical Immunosensor Using Antibody-Conjugated Pt-Doped CdTe QDs as Enzyme-Free Labels for Sensitive HER2 Detection Based on a Magnetic Framework.

ABSTRACT: Tumor markers are highly sensitive and play an important role in the early diagnosis of cancer. We developed an electrochemical sandwich-type immunosensor that detects human epidermal growth factor receptor 2 (HER2). Magnetic framework (Fe₃O₄@ TMU-24) and AuNPs (Fe₃O₄@ TMU-24 -AuNPs) are utilized in this sensing platform. In addition to their high specific surface area and excellent biocompatibility, Fe₃O₄@ TMU-24-AuNPs nanocomposites exhibited excellent electrocatalytic properties. The primary antibody of HER2 (Ab₁) was immobilized on the surface of the Fe₃O₄@ TMU-24-AuNPs. In this sensing method, palatine doped to CdTe QDs (Pt: CdTe QDs) is utilized as a novel labeling signal biomolecule (secondary antibodies). Pt: CdTe QDs own good biocompatibility and excellent catalytic performance. The amperometric technique was used to achieve the quantitative determination of HER2 by using a sandwich-type electrochemical immunosensor. Under the optimum conditions, the dependency of the current signal and HER2 concentration showed a linear region from 1 pg ml^-1-100 ng ml^-1 with 0.175 pg ml^-1 as the limit of detection. This biosensing device also showed long stability and good reproducibility, which can be used for the quantitative assay of HER2.

SUBMITTER: Ehzari H

PROVIDER: S-EPMC9218600 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Sensitive sandwich-type electrochemical SARS-CoV‐2 nucleocapsid protein immunosensor

Project description:Graphical abstract A sensitive and fast sandwich-type electrochemical SARS-CoV‑2 (COVID-19) nucleocapsid protein immunosensor was prepared based on bismuth tungstate/bismuth sulfide composite (Bi2WO6/Bi2S3) as electrode platform and graphitic carbon nitride sheet decorated with gold nanoparticles (Au NPs) and tungsten trioxide sphere composite (g-C3N4/Au/WO3) as signal amplification. The electrostatic interactions between capture antibody and Bi2WO6/Bi2S3 led to immobilization of the capture nucleocapsid antibody. The detection antibody was then conjugated to g-C3N4/Au/WO3 via the affinity of amino-gold. After physicochemically characterization via transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) analysis were implemented to evaluate the electrochemical performance of the prepared immunosensor. The detection of SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) in a small saliva sample (100.0 µL) took just 30 min and yielded a detection limit (LOD) of 3.00 fg mL−1, making it an effective tool for point-of-care COVID-19 testing. Supplementary Information The online version contains supplementary material available at 10.1007/s00604-021-05092-6.

| S-EPMC8609265 | biostudies-literature

Ultra-highly fluorescent N doped carbon dots-CdTe QDs nanohybrids with excitation-independent emission in the blue-violet region.

Project description:Luminescent carbon dots (CDs) are of significant practical application interest such as in optoelectronic devices and sensitive probing in the life science and environment fields. In this study, N doped CDs-CdTe quantum dots (QDs) nanohybrids (CdTe/N-CDs) were synthesized by a plasma heating process using silk fibroin and CdTe QDs as precursors. The synthesis, doping, hybridizing and passivation of the CdTe/N-CDs were carried out in a single-step process. The as-synthesized CdTe/N-CDs dispersed in ethanol exhibited blue-violet photoluminescence with excitation-independent emission characteristics (strong emissions at 405 nm and 429 nm, and a weak emission at 456 nm). Additionally, the optimal excitation wavelength for the CdTe/N-CDs was found at 360-380 nm, which very closely matches the intrinsic wavelength of GaN-based LEDs. Furthermore, the obtained CdTe/N-CDs exhibited a very high quantum yield of ∼84%, showing great potential in developing chip-based high performance optoelectronics devices. The emission mechanism and emission enhancement by related factors including N-bonded configurations in the carbon base and the transfer of photo-excited electrons from the CdTe QDs to the N doped CDs were studied, as well.

| S-EPMC9088203 | biostudies-literature

Electrochemical Oxidation of Sulfonamides with Boron-Doped Diamond and Pt Anodes.

Project description:Electrochemical oxidation processes usually favored specific degradation pathways depending on anode materials. In this work, a series of sulfonamides (SNs) were degraded by electrochemical oxidation. Compared to Pt anodes (0.1567-0.1795?h-1), degradation rates of SNs were much higher at boron-doped diamond (BDD) anodes (2.4290-13.1950?h-1). However, the same intermediates were detected in the two anode systems. Due to the strong oxidizing ability of BDD anodes, a large amount of intermediates with high toxicities were initially generated and then finally reduced in the BDD anode systems, while the amount of intermediates continuously increased in the Pt anode systems. Additionally, SNs were degraded faster in Na2SO4 than NaH2PO4 electrolytes at BDD anodes, while they were similar at Pt anodes. This study demonstrated that the degradation pathways of SNs at BDD and Pt anodes were similar, but the evolutions of intermediate amounts and toxicities were different due to their varied oxidizing abilities.

| S-EPMC6909879 | biostudies-literature

Electrochemical immunosensor based on AuBP@Pt nanostructure and AuPd-PDA nanozyme for ultrasensitive detection of APOE4.

Project description:An ultrasensitive sandwich-type electrochemical immunosensor based on AuBP@Pt nanostructures and AuPd-PDA nanozyme was developed for the detection of apolipoprotein E4 (APOE4) which was an important risk factor for Alzheimer's disease (AD). In this work, gold nanobipyramid coated Pt (AuBP@Pt) nanostructures were prepared and applied to electrochemical immunosensors as a substrate material. AuBP@Pt nanostructures have advantages of electrical conductivity and large electroactive area, which could greatly increase electron transfer rate. In previous work, we designed AuPd alloy modified polydopamine (AuPd-PDA) nanozyme which catalyzed the decomposition of hydrogen peroxide (H2O2). AuPd-PDA nanozyme was used to label detection antibody due to excellent catalytic capability and stability in this new paper. And the concentration of APOE4 could be detected quantitatively by variation for transient current. As a result, the electrochemical immunosensor based on AuBP@Pt and AuPd-PDA exhibited a wide linear range from 0.05 to 2000 ng mL-1 and low detection limit of 15.4 pg mL-1 (S/N = 3). Furthermore, the designed biosensor displayed good selectivity in phosphate buffer saline (PBS) buffer solution or commercial goat serum, which provided a promising tool for early diagnosis of AD.

| S-EPMC9049899 | biostudies-literature

Ultrasensitive sandwich-type electrochemical immunosensor based on trimetallic nanocomposite signal amplification strategy for the ultrasensitive detection of CEA.

Project description:A novel and ultrasensitive sandwich-type electrochemical immunosensor was designed for the quantitative detection of carcino-embryonic antigen (CEA). This immunosensor was developed by using the trimetallic NiAuPt nanoparticles on graphene nanosheets (NGs) nanosheets (NiAuPt-NGs) as excellent labels and β-cyclodextrin functionalized reduced graphene oxide nanosheets (CD-NGs) as the platform. The CD-NGs with high specific surface area good biocompatibility and the ideal dispersibility was used to capture the primary antibodies (Ab1) efficiently. The trimetallic NiAuPt-NGs nanocomposites were used as the labels for signal amplification, showing better electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2), which is much better than that the monometallic Pt-NGs, bimetallic NiPt-NGs and AuPt-NGs due to the synergetic effect presented in NiAuPt-NGs. The NiAuPt-NGs nanocomposites consist of tightly coupled nanostructures of Au, Ni and Pt, which have neither an alloy nor a core-shell structure. Under the optimal conditions, a linear range from 0.001-100 ng/mL and a low detection limit of 0.27 pg/mL were obtained for CEA. The proposed electrochemical sandwich-type immunosensor may have a promising application in bioassay and it enriches the electrochemical immunoassays.

| S-EPMC4973229 | biostudies-literature

A sandwich-type electrochemical immunosensor based on the biotin- streptavidin-biotin structure for detection of human immunoglobulin G.

Project description:A sandwich-type immunosensor is designed and fabricated to detect the human immunoglobulin G (HIgG) using polyaniline and tin dioxide functionalized graphene (GS-SnO2-PAN) as the platform and biotin-functionalized amination magnetic nanoparticles composite (B-Fe3O4@APTES) as the label. GS-SnO2-PAN is used as the sensing agent to capture the primary anti-HIgG (Ab1) and SnO2 reduces the stack of GS. The B-Fe3O4@APTES with a large surface area and excellent biocompatibility captures second antibody (Ab2) efficiently based on the highly selective recognition of streptavidin to biotinylated antibody. The B-Fe3O4@APTES has better electro-catalytic activity in the reduction of hydrogen peroxide (H2O2) and the "biotin-streptavidin-biotin" (B-SA-B) strategy leads to signal amplification. Under optimal conditions, the immunosensor has a wide sensitivity range from 1 pg/L to 10 ng/L and low detection limit of 0.33 pg/L (S/N = 3) for HIgG. The immunosensor has high sensitivity, fast assay rate, as well as good reproducibility, specificity, and stability especially in the quantitative detection of biomolecules in serum samples.

| S-EPMC4780222 | biostudies-literature

Live-stream characterization of cadmium-induced cell death using visible CdTe-QDs.

Project description:Characterization of cell death currently requires the use of indirect markers, which has largely limited the ability to monitor cell death processes inside the cell. Here, we introduce a new method for the characterization of cell death mechanisms using cadmium telluride quantum dots (CdTe-QDs). Using visible CdTe-QDs with mesenchymal cells (e.g. synoviocytes), live-stream imaging allowed for visualization of cadmium-induced cell death, combining characteristics of apoptosis and autophagy. Initially, similar anti-proliferative effect was observed between 10?µg/ml Cd2+ and CdTe-QDs at 24?h (cell index/cell density ratio decreased from 0.6 to -16.6, p?<?0.05) using techniques that do not require the capacity of CdTe-QDs. Apoptosis was confirmed by the quantification of morphological parameters (reduced surface area, increased cell thickness) and positive labeling with annexin V. Autophagy was confirmed by monodansylcadaverine staining, identifying similar autophagic vacuoles with both Cd2+ and CdTe-QD. However, QD imaging allowed for visualization of cadmium elements inside cell structures and their kinetic changes leading to cell death. Cell death characteristics were similar in inflammatory and non-inflammatory environment but were induced up to 4?h earlier in the former. Therefore, live-stream imaging of a visible cytotoxic agent has useful applications not currently possible with indirect methods, including chronological monitoring of cell death.

| S-EPMC6105671 | biostudies-literature

Enzyme-free electrochemical immunosensor based on methylene blue and the electro-oxidation of hydrazine on Pt nanoparticles.

Project description:Enzyme-free electrochemical sensors enable rapid, high sensitivity measurements without the limitations associated with enzyme reporters. However, the performance of non-enzymatic electrochemical sensors tends to suffer from slow electrode kinetics and poor signal stability. We report a new enzyme-free electrochemical immunosensor based on a unique competitive detection scheme using methylene blue (MB), hydrazine and platinum nanoparticles (Pt NPs). This scheme is coupled with a robust immunosandwich format employing a MB-labelled detection antibody as a non-enzymatic reporter. In the presence of the target antigen, surface-immobilized MB consumes interfacial hydrazine thereby diminishing the electro-oxidation of hydrazine on Pt NPs. Thus, the concentration of the antigen is directly proportional to the reduction in the electrochemical signal. For proof-of-concept, this sensor was used to detect Plasmodium falciparum histidine-rich protein 2 (PfHRP2), an important malaria biomarker, in unadulterated human saliva samples. Chronocoulometric measurements showed that this platform exhibits pM-range sensitivity, high specificity and good reproducibility, making it well suited for many biosensing applications including noninvasive diagnostic testing.

| S-EPMC5342929 | biostudies-literature

A sandwich amperometric immunosensor for the detection of fowl adenovirus group I based on bimetallic Pt/Ag nanoparticle-functionalized multiwalled carbon nanotubes.

Project description:An enzyme-free sandwich amperometric immunosensor based on bimetallic Pt/Ag nanoparticle (Pt/AgNPs)-functionalized chitosan (Chi)-modified multiwalled carbon nanotubes (MWCNTs) as dual signal amplifiers and Chi-modified MWCNTs (MWCNTs-Chi) as substrate materials was developed for ultrasensitive detection of fowl adenovirus group I (FAdV-I). MWCNTs have a large specific surface area, and many accessible active sites were formed after modification with Chi. Hence, MWCNTs-Chi, as a substrate material for modifying glassy carbon electrodes (GCEs), could immobilize more antibodies (fowl adenovirus group I-monoclonal antibody, FAdV-I/MAb). Multiple Pt/AgNPs were attached to the surface of MWCNTs-Chi to generate MWCNTs-Chi-Pt/AgNPs with high catalytic ability for the reaction of H2O2 and modified active sites for fowl adenovirus group I-polyclonal antibody (FAdV-I/PAb) binding. Amperometric i-t measurements were employed to characterize the recognizability of FAdV-I. Under optimal conditions, and the developed immunosensor exhibited a wide linear range (100.93 EID50 mL-1 to 103.43 EID50 mL-1), a low detection limit (100.67 EID50 mL-1) and good selectivity, reproducibility and stability. This immunosensor can be used in clinical sample detection.

| S-EPMC10762159 | biostudies-literature

Multiple Emitting Amphiphilic Conjugated Polythiophenes-Coated CdTe QDs for Picogram Detection of Trinitrophenol Explosive and Application Using Chitosan Film and Paper-Based Sensor Coupled with Smartphone.

Project description:Novel multiple emitting amphiphilic conjugated polythiophene-coated CdTe quantum dots for picogram level determination of the 2,4,6-trinitrophenol (TNP) explosive are developed. Four biocompatible sensors, cationic polythiophene nanohybrids (CPTQDs), nonionic polythiophene nanohybrids (NPTQDs), anionic polythiophene nanohybrids (APTQDs), and thiophene copolymer nanohybrids (TCPQDs), are designed using an in situ polymerization method, which shows highly enhanced fluorescence intensity and quantum yield (up to 78%). All sensors are investigated for nitroexplosive detection to provide a remarkable fluorescence quenching for TNP and the quenching efficiency reached 96% in the case of TCPQDs. The fluorescence of the sensors are quenched by TNP through inner filter effect, electrostatic, π-π, and hydrogen bonding interactions. Under optimal conditions, the detection limits of CPTQDs, NPTQDs, APTQDs, and TCPQDs are 2.56, 7.23, 4.12, and 0.56 × 10-9 m, respectively, within 60 s. More importantly, portable, cost effective, and simple to use paper strips and chitosan film are successfully applied to visually detect as little as 2.29 pg of TNP. The possibility of utilizing a smartphone with a color-scanning APP in the determination of TNP is also established. Moreover, the practical application of the developed sensors for TNP detection in tap and river water samples is described with satisfactory recoveries of 98.02-107.50%.

| S-EPMC6343090 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data