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In this work, a triggerable H

A low-cost, simple, portable and sensitive paper-based electrochemical sensor was established for the detection of K-562 cell in point-of-care testing. The hybrid material of 3D Au nanoparticles/graphene (3D Au NPs/GN) with high specific surface area and ionic liquid (IL) with widened electrochemical windows improved the good biocompatibility and high conductivity was modified on paper working electrode (PWE) by the classic assembly method and then employed as the sensing surface. IL could not only enhance the electron transfer ability but also provide sensing recognition interface for the conjugation of Con A with cells, with the cell capture efficiency and the sensitivity of biosensor strengthened simultaneously. Concanavalin A (Con A) immobilization matrix was used to capture cells. As proof-of-concept, the paper-based electrochemical sensor for the detection of K-562 cells was developed. With such sandwich-type assay format, K-562 cells as model cells were captured on the surface of Con A/IL/3D AuNPs@GN/PWE. Con A-labeled dendritic PdAg NPs were captured on the surface of K-562 cells. Such dendritic PdAg NPs worked as catalysts promoting the oxidation of thionine (TH) by H2O2 which was released from K-562 cells via the stimulation of phorbol 12-myristate-13-acetate (PMA). Therefore, the current signal response was dependent on the amount of PdAg NPs and the concentration of H2O2, the latter of which corresponded with the releasing amount from cells. So, the detection method of K-562 cell was also developed. Under optimized experimental conditions, 1.5×10(-14) mol of H2O2 releasing from each cell was calculated. The linear range and the detection limit for K-562 cells were determined to be 1.0×10(3)-5.0×10(6) cells/mL and 200 cells/mL, respectively. Such as-prepared sensor showed excellent analytical performance with good fabrication reproducibility, acceptable precision and satisfied accuracy, providing a novel protocol in point-of-care testing of cells.

A novel electrochemical lab-on-paper cyto-device (ELPCD) was fabricated to demonstrate sensitive and specific cancer cell detection as well as in-situ monitoring of multi-glycans on living cancer cells. In this ELPCD, aptamers modified three-dimensional macroporous Au-paper electrode (Au-PE) was employed as the working electrode for specific and efficient cancer cell capture. Using a sandwich format, sensitive and reproducible cell detection was achieved in this ELPCD on the basis of the electrochemical signal amplification of the Au-PE and the horseradish peroxidase-lectin electrochemical probe. The ELPCD displayed excellent analytical performance for the detection of four K562 cells with a wide linear calibration range from 550 to 2.0×10(7) cells mL(-1). Then, this ELPCD was successfully applied to determine cell-surface multi-glycans in parallel and in-situ monitor multi-glycans expression on living cells in response to drug treatment through in-electrode 3D cell culture. The proposed method provides promising application in decipherment of the glycomic codes as well as clinical diagnosis and treatment in early process of cancer.

Disposable analytical devices for developing sensitive and label-free monitoring of cancerous cells would be attractive for cancer research. Here, paper-based electroanalytical devices based on impedance spectrometry were applied for the study of K562 cells and the toxic effect of anticancer drugs. The proposed device integrating gold nanorods modified ITO electrodes could provide a biocompatible surface for immobilization of living cells maintaining their bioactivity. The impedance results exhibited good correlation to the logarithmic value of cell numbers ranging from 7.5 × 10(2) to 3.9 × 10(6) cells mL(-1) with a detection limit of 500 cells mL(-1). Furthermore, this strategy was used to evaluate the cytotoxic effects of arsenic trioxide and cyclophosphamide. Results obtained by the impedimetric method correlate well with the conventional cell viability assay. Cells exposed to drugs exhibited a prominent reduction of impedance data, showing an inverse dose-dependent relationship. This simple, cost-effective and portable paper-based electrochemical analytical device could provide a new impedance platform for applications in monitoring cell behavior, pharmacological studies and toxicological analyses.

Peanut agglutinin (PNA) binding glycoproteins from four Hodgkin's desease (HD)-derived cell lines and a variety of cell lines/peripheral blood cells representative of the lymphoid and myeloid lineages were identified by probing nitrocellulose membranes of SDS-PAGE separated NP40 solubilized cellular glycoproteins with [125I]-labelled PNA. The two Hodgkin's cell lines Ho and L428 demonstrated the most heterogeneous glycoprotein profiles each expressing 15 PNA binding glycoproteins, respectively. The two remaining Hodgkin's lines Co and L591 expressed only four glycoproteins each and these were all also commonly expressed by Ho and L428. Comparative analysis with all other cell types studied revealed the expression of five glycoproteins restricted to Ho (gp42, gp40, gp38, gp24 and gp22) and six restricted to L428 (gp180, gp75, gp40, gp38, gp24 and gp22). Four of these, gp40, gp38, gp24 and gp22 were commonly expressed by both Ho and L428. Of cell lines of myeloid lineage studied only the erythroleukemia cell line K562 expressed detectable glycoproteins also expressed by some of the Hodgkin's cell lines (gp 110, gp96, gp50 and gp45). Only one glycoprotein, gp20 expressed by Ho was also commonly expressed by normal peripheral blood granulocytes. This limited study has thus succeeded in demonstrating for the range of cell types studied, that some glycoproteins with terminal d-galactose β (1 3) N-acetyl galactosamine oligosaccharide sequences are apparently restricted to two of the HD cell lines. Moreover, the heterogeneous glycoprotein profiles obtained for the HD cell lines Ho and L428 suggests that galactosylation processes in these two cell lines is aberrant.