Publications (95) View all
-
Dataset: chemsci
-
Article: Size-dependent cellular uptake efficiency, mechanism, and cytotoxicity of silica nanoparticles toward HeLa cells.
[show abstract] [hide abstract]
ABSTRACT: In this study, we investigated and reported the cellular uptake efficiency, mechanism, and cytotoxicity of silica nanoparticles (SNPs) with different sizes. Using confocal laser scanning microscope (CLSM), flow cytometry (FCM), and graphite furnace atomic absorption spectrometry (GFAAS), the qualitative and quantitative experimental results showed that the cellular uptake of SNPs toward HeLa cells is size-dependent. To further examine the uptake process, three different inhibitors including sucrose, Filipin III, and Cytochalasin D (Cyt D) were introduced to pretreat the HeLa cells. It appeared that the largest SNPs (SNPs-307.6) take an energy-dependent uptake pathway (clathrin dependent and caveolin independent) while that for the medium size SNPs-167.8 involves clathrin and caveolin dependent endocytosis. In contrast, the smallest SNPs (SNPs-55.6) follow not only energy required clathrin and caveolin dependent endocytosis but also an energy independent pathway to efficiently enter the cells. Moreover, the cellular uptake efficiency of SNPs, which also show excellent biocompatibility, is size-dependent in the order of 55.6>167.8>307.6nm. This knowledge is fundamentally important and will facilitate more development of size-defined SNPs as the transporters for various purposes.Talanta 03/2013; 107C:408-415. · 3.79 Impact Factor -
Article: Coupling Isoelectric Focusing Gel Electrophoresis to Mass Spectrometry by Electrostatic Spray Ionisation.
[show abstract] [hide abstract]
ABSTRACT: Gel electrophoresis has been used for decades as a high-resolution separation technique for proteins and protein isomers, but limited in the coupling with MS because of low throughput and poor automaticity compared with LC-MS. In this work, we have developed an ambient ionisation strategy, electrostatic spray ionisation, for in-situ ionisation of proteins or peptides inside a surfactant-free polyacrylamide gel. The samples can be first separated by isoelectric focusing in a gel and then quickly in-situ detected by scanning the gel with the electrostatic spray ionisation mass spectrometry. With this strategy, nanograms of proteins or peptides inside a band are enough to be ionised for MS detection. This method for protein/peptide spots visualization is sensitive providing sample molecular weight information whilst avoiding spot staining and chemical extraction procedures that can introduce contaminants and sample loss. Proof-of-principle results have demonstrated that the electrostatic spray ionisation can produce sample ions from a complex background and with a spatial resolution matching the isoelectric focusing, therefore a good choice to couple directly isoelectric focusing gel electrophoresis with mass spectrometry.Analytical Chemistry 03/2013; · 5.86 Impact Factor -
Article: Visual and high-throughput detection of cancer cells using a graphene oxide-based FRET aptasensing microfluidic chip.
[show abstract] [hide abstract]
ABSTRACT: Rapid and efficient measurement of cancer cells is a major challenge in early cancer diagnosis. In the present study, a miniature multiplex chip was created for in situ detection of cancer cells by implementing a novel graphene oxide (GO)-based Förster resonance energy transfer (FRET) biosensor strategy, i.e. assaying the cell-induced fluorescence recovery from the dye-labeled aptamer/graphene oxide complex. Fluorescence intensity measurement and image analyses demonstrated that this microfluidic biosensing method exhibited rapid, selective and sensitive fluorescence responses to the quantities of the target cancer cells, CCRF-CEM cells. Seven different cancer cell samples can be measured at the same time in such a microfluidic chip. The linear response for target CCRF-CEM cells in a concentration range from 2.5 × 10(1) to 2.5 × 10(4) cells mL(-1) was obtained, with a detection limit about 25 cells mL(-1), which is about ten times lower than those of normal biosensors. The novel fluorescence biosensing microfluidic chip supplies a rapid, visible and high-throughput approach for early cancer diagnosis with high sensitivity and specificity.Lab on a Chip 09/2012; 12(22):4864-9. · 5.67 Impact Factor -
Article: Nanocomposites of palladium nanoparticle-loaded mesoporous carbon nanospheres for the electrochemical determination of hydrogen peroxide.
[show abstract] [hide abstract]
ABSTRACT: Palladium nanoparticles (Pd NPs) were loaded in situ on novel mesoporous carbon nanospheres (MCNs), which possess high specific surface area and large pore volume. The resulting Pd/MCNs hybrid nanocomposites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). By using Pd/MCNs as the catalyst matrices to modify the surface of glassy carbon electrode, a nonenzymatic sensor was developed for the determination of hydrogen peroxide (H(2)O(2)). Cyclic voltammetry (CV) and amperometry (at an applied potential of -0.30V versus SCE) were used to study and optimize the performance of the electrochemical sensor. It was demonstrated that the sensor not only exhibits good electrocatalytic activity toward the reduction of H(2)O(2) but also has high sensitivity (307.5μAmM(-1)cm(-2)), low detection limit of 1.0μM, and wide linear response range from 7.5μM to 10mM. Moreover, the sensor shows excellent stability and anti-interference capability for the detection of H(2)O(2).Talanta 09/2012; 99:256-61. · 3.79 Impact Factor
