Detection Of MCF-7 Cells Research Articles

Leakage-free polypyrrole-Au nanostructures for combined Raman detection and photothermal cancer therapy.

A bifunctional gold-coated polypyrrole (PPy-Au) nanostructure with Raman and photothermal activity was developed, in which polypyrrole spheres (PPy NSs) were used as the core and coated with small Au NPs to form polypyrrole-Au (PPy-Au) nanostructures. As a result of the contribution from the coated Au nanoparticles (Au NPs), coupling occurred between the Au NPs and the PPy NSs, leading to an enhanced pyrrole Raman signal. PPy-Au nanostructures were thus used as Raman tags without requiring additional Raman dyes labeling and leaking the cargo dyes even in the absence of a complicated encapsulation process. When conjugated with aptamer S2.2, the nanostructures could specifically bind with the membrane protein MUC1, a kind of tumor-related biomarker that is overexpressed on the surface of human breast cancer cells (MCF-7). The specific detection of MCF-7 cells was thus achieved based on the pyrrole Raman signal. Moreover, the capacity of the PPy-Au nanostructures for transforming NIR light into heat was also greatly enhanced because of the coupling between the Au NPs and the PPy NSs, as indicated by the efficiency of the photothermal conversion up to 70.0% compared to 44.7% for the pure PPy NSs. Photothermal experiments proved that MCF-7 cells incubated with the nanostructures nearly died under 808 nm irradiation (0.5 W cm-2) for 20 min, and the tumors bearing on the mice were also effectively inhibited after the PTT.

Versatile aptasensor for electrochemical quantification of cell surface glycan and naked-eye tracking glycolytic inhibition in living cells

Quantifying the glycan expression status on cell surfaces is of vital importance for insight into the glycan function in biological processes and related diseases. Here we developed a versatile aptasensor for electrochemical quantification of cell surface glycan by taking advantage of the cell-specific aptamer, and the lectin-functionalized gold nanoparticles acting as both a glycan recognition unit and a signal amplification probe. To construct the aptasensor, amine-functionalized mucin 1 protein (MUC1) aptamer was first covalently conjugated to carboxylated-magnetic beads (MBs) using the succinimide coupling (EDC-NHS) method. On the basis of the specific recognition between aptamer and MUC1 protein that overexpressed on the surface of MCF-7 cells, the aptamer conjugated MBs showed a predominant capability for cell capture with high selectivity. Moreover, a lectin-based nanoprobe was designed by noncovalent assembly of concanavalin A (ConA) on gold nanoparticles (AuNPs). This nanoprobe incorporated the abilities of both the specific carbohydrate recognition and the signal amplification based on the gold-promoted reduction of silver ions. By coupling with electrochemical stripping analysis, the proposed sandwich-type cytosensor showed an excellent analytical performance for the ultrasensitive detection of MCF-7 cells and quantification of cell surface glycan. More importantly, taking advantage of Con A-gold nanoprobe catalyzed silver enhancement, the proposed method was further used for naked-eye tracking glycolytic inhibition in living cells. This aptasensor holds great promise as a new point-of-care diagnostic tool for analyzing glycan expression on living cells and further helps cancer diagnosis and treatment.

Sensitive Detection of MCF-7 Cells Based on Poly Calcein Modified Electrode and Its Applied in Cytotoxicity Assay

Sensitive Detection of MCF-7 Cells Based on Poly Calcein Modified Electrode and Its Applied in Cytotoxicity Assay

A mini-electrochemical system integrated micropipet tip and pencil graphite electrode for detection of anticancer drug sensitivity in vitro

Developing a reliable and cost-effective miniaturized electroanalysis tool is of vital importance for cell electrochemical analysis. In this work, a novel mini-electrochemical system has been constructed for trace detection of cell samples. The mini-electrochemical system was constructed by integrating a pencil graphite modified by threonine (PT/PGE) as working electrode, an Ag/AgCl (Sat'd) as reference electrode, platinum wire as counter electrode and a micropipet tip as electrochemical cell. The mini-electrochemical system not only saved dramatically usage of samples from 500μL in traditional electrochemical system to 10μL, but also possessed an adjustable active surface area by changing the length of PT/PGE immersed into the cell suspension from 3mm to 15mm, and the linear equation was ipa=2.25l−2.64 (R2=0.990). The system was successfully used in detection of MCF-7 cells, and a nonlinear exponent relationship between peak current and the cell number range from 3.0×l03 to 7.0×l06cellsmL−1 was established firstly with the index equation ipa=59.557e (−C/1.709)−71.486 (R2=0.954). Finally, the system was used for evaluating the sensitivity of cyclophosphamide on MCF-7 cell, and the result was corresponded well with that of MTT assay. The proposed system is sufficiently simple, cheap and easy operated, and could be applied in electrochemical detection of other biological samples.

An aptasensor for sensitive detection of human breast cancer cells by using porous GO/Au composites and porous PtFe alloy as effective sensing platform and signal amplification labels

A novel aptamer biosensor for cancer cell assay has been reported on the basis of ultrasensitive electrochemical detection. The assay uses the aptamer as a capture probe to recognize and bind the tumor marker on the surface of the cancer cells, forming an aptamer-based sandwich structure for MCF-7 cells detection. Functionalized nanoporous materials, porous graphene oxide/Au composites (GO/Au composites) and porous PtFe alloy have been introduced into the biosensor. Owing to the large surface area and versatile porous structure, the use of nanoporous materials can significantly improve the analysis performance of the biosensors by loading of large amounts of molecules and accelerating diffusion rate. Under the optimized experimental conditions, the proposed aptamer biosensor exhibited excellent analytical performance for MCF-7 cells determination, ranging from 100 to 5.0×107cellsmL−1 with the detection limit of 38cellsmL−1. The biosensor showed good selectivity, acceptable stability and reproducibility, and developed a highly sensitive and selective method for cancer cells detection.

Anti-EpCAM modified LC-SPDP monolayer on gold microelectrode based electrochemical biosensor for MCF-7 cells detection

A succinimidyl 6-(3-[2-pyridyldithio]-propionamido) hexanoate (LC-SPDP) self-assembled monolayer (SAM) prepared onto a 500μm (diameter) gold microelectrode (Au) surface has been utilized for covalent immobilization of anti-EpCAM antibody. Amino group on anti-EpCAM antibody was covalently bound with succinimidyl group on SAM via amide bond and unreacted active groups of LC-SPDP were blocked using 1% ethanol amine (EA). These anti-EpCAM/LC-SPDP/Au electrodes were characterized using cyclic voltammetric (CV) and fluorescence techniques, respectively. The anti-EpCAM/LC-SPDP/Au electrodes were exposed to solutions with different MCF-7 cell concentrations and CV technique was used to determine the cell concentration. Further, CV studies on blank 500 and 50μm (diameter) gold microelectrodes were used to identify cell via molecular profiling using ferrocene amidopentyl carboxylic acid based redox tagging and magnetic beads based enhancement. CV results confirm that the anti-EpCAM/LC-SPDP/Au based biosensor could detect MCF-7 cells in the range of 1×105–1×108 with correlation coefficient of 0.999 and detection limit of 1×105cellsml−1 i.e. 100cells in solution used for incubation (1μl). Molecular profiling studies suggest that smaller size microelectrode (50μm; diameter) with magnetic beads based enhancement can be employed to identify cell type. This work establishes the feasibility of using microelectrode based platform for breast cancer specific MCF-7 cell concentration estimation and their molecular profiling.

Electrochemiluminescent detection of Mucin 1 protein and MCF-7 cancer cells based on the resonance energy transfer

A novel sensing strategy for sensitive detection of mucin 1 protein (MUC1) and MCF-7 cells based on electrochemiluminescence (ECL) resonance energy transfer (ERET) from bis(2,2'-bipyridine)-(5-aminophenanthroline)ruthenium(II) (Ru1) to graphene oxide (GO) was proposed. The MUC1 aptamer was covalently combined with Ru1 (Ru1-aptamer) using aqueous carbodiimide coupling chemistry. Due to the strong noncovalent interaction between the Ru1-aptamer and GO, the ECL of Ru1 was efficiently quenched because of the ERET. In the presence of a target MUC1 protein, the binding between the Ru1-aptamer and MUC1 disturbed the interaction between the Ru1-aptamer and GO. These interactions led to the release of the Ru1-aptamer from GO, and resulted in the restoration of Ru1 ECL. This was shown to detect MUC1 protein sensitively in a linear range from 64.9 to 1036.8 nM with a detection limit of 40 nM. With further application in the detection of MCF-7 cells, the presented method could respond at concentrations as low as 30 cancer cells per mL. By substituting the aptamer and the corresponding target, this method could be conveniently extended for the sensitive detection of other biomolecules.