[Quercetin induces apoptosis of human breast cancer cells by activiting PTEN and inhibiting PI3K/AKT and JNK signaling pathways].

Objective To investigate the effect of quercetin on cell proliferation and apoptosis of MCF-7 human breast cancer cells, and effects of signaling pathways of PTEN/PI3K/AKT and c-Jun N-terminal kinase (JNK) signaling pathway. Methods MCF-7 cells were treated with quercetin (0, 20, 40, 60, 80, 100 μmol/L) CCK-8 assay was used to detect the cell proliferation, and cell apoptosis was assayed by flow cytometry. Hochesst33342 staining was used to observe the changes of nuclear number and karyotype, and flow cytometry was employed to detect cell apoptosis.

Electrochemical mixed aptamer-antibody sandwich assay for mucin protein 16 detection through hybridization chain reaction amplification.

A mixed aptamer-antibody sandwich assay for the determination of mucin protein 16 (MUC16) was developed based on hybridization chain reaction (HCR) with methylene blue (MB) as an electrochemical indicator. First, MUC16 antibody was adsorbed onto the surface of the Au nanoparticle (AuNP)-modified indium tin oxide (ITO) electrode to effectively capture the target MUC16. After MUC16 was captured by the MUC16 aptamer, an antibody/MUC16/aptamer sandwich structure formed for the highly selective detection of MUC16.

Amperometric sandwich immunoassay for determination of myeloperoxidase by using gold nanoparticles encapsulated in graphitized mesoporous carbon.

An ultrasensitive sandwich-type electrochemical immunosensor was developed for the amperometric determination of serum myeloperoxidase (MPO). The method is making use of (a) gold nanoparticles encapsulated in graphitized mesoporous carbons (AuNP@GMC); and (b) horseradish peroxidase (HRP) labeled secondary antibody (HRP@Ab) immobilized on AuNP@GMC. MPO capture antibody (Ab) was immobilized on the electrode modified with an AuNP-graphene oxide nanocomposite.

Electrochemical determination of the activity of DNA methyltransferase based on the methyl binding domain protein and a customized modular detector.

An electrochemical method is described for the determination of the activity of the DNA methyltransferase (MTase). The assay was based on the use of a commercially available customized electromagnetic modular detector, which consisted of a magnetic switch, electrical connectors and a screen-printed electrode modified with graphene oxide. The biotinylated single-strand DNA (ss-DNA) S1 was absorbed by streptavidin-modified magnetic beads (MBs) via streptavidin-biotin interaction.

Electrochemical determination of BCR/ABL fusion gene based on in situ synthesized gold nanoparticles and cerium dioxide nanoparticles.

An efficient DNA electrochemical biosensor, based on the gold nanoparticles (GNPs) in situ synthesized at the surface of multiwalled carbon nanotubes (MWCNTs), cerium dioxide (CeO2) and chitosan (Chits) composite membrane, was developed for the detection of BCR/ABL fusion gene in chronic myelogenous leukemia (CML). The capture probe was attached onto the nanocomposite membrane modified glassy carbon electrode (GCE) through the conjugated structure. Owing to the synergistic effects of CeO2 nanoparticles with a strong adsorption ability and MWCNTs with a large surface area and excellent electron transfer ability, the prepared composite membrane was demonstrated an efficient electron transfer ability.

Ultrasensitive electrochemical immunosensor for HE4 based on rolling circle amplification.

A novel electrochemical immunoassay system for the detection of human epididymis-specific protein 4 (HE4) was developed. A chitosan-titanium carbide (TiC) nanocomposition film was first electrodeposited onto a tin-doped indium oxide (ITO) electrode at a constant potential. Gold (Au) nanoparticles were then electrodeposited on the surface of the chitosan-TiC film by cyclic voltammetry (CV).

Improved electrochemical immunosensor for myeloperoxidase in human serum based on nanogold/cerium dioxide-BMIMPF6/L-Cysteine composite film.

An electrochemical immunosensing assay for myeloperoxidase (MPO) determination in human serum has been developed. Firstly, L-Cysteine was initially electropolymerized on an Au electrode to form L-Cysteine film. After that cerium dioxide (CeO2) dispersed in 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) were immobilized on the L-Cysteine film.