Biomedical subjects

Guanglu Ge

Publications and source records attributed to Guanglu Ge.

2 recordsLinked to original sources

PubMed2006

MAC mode atomic force microscopy studies of living samples, ranging from cells to fresh tissue.

Magnetic AC mode (MAC mode) atomic force microscopy (AFM), a novel type of tapping mode AFM in which the cantilever is driven directly by a magnetic field, is a powerful tool for imaging with high spatial resolution and better signal-to-noise in liquid environment. It may largely extend the application of AFM to living samples, especially those are sensitive to cantilever forces, even to multilayer tissue samples. However, there are few reports on the imaging of living cells by MAC mode AFM previously. In our present study, we explore the optimal imaging conditions of MAC mode AFM on living astrocytes and fresh arterial intima surface. We also used nude tips for PicoTREC panel (i.e., Aux in BNC, a new data collecting channel) to image living samples and discussed its difference with phase imaging. We show that living biological samples can be imaged by MAC mode AFM at details of comparable resolution as those by high resolution scanning electron microscopy. Furthermore, the combination of height, amplitude, phase and TREC panel signals provide abundant informations for the characteristics of living samples, such as topography, profile, stiffness and adhesion.

Animals↗

PubMed2004

Electrochemically programmed, spatially selective biofunctionalization of silicon wires.

A method for the spatially selective biofunctionalization of silicon micro- and nanostructures is reported, and results are presented for both single-crystal silicon (111) or (100) surfaces. An electroactive monolayer of hydroquinone was formed on the surface of H-terminated silicon working electrodes via an olefin reaction with UV-generated surface radicals. Molecules presenting either cyclopentadiene or a thiol group can be immobilized onto the regions where the hydroquinone has been oxidized. Molecular size and crystal orientation are evaluated as important factors that dictate the electrode stability in aqueous solution under anodic potentials. Monolayers composed of smaller molecules on (111) surfaces exhibit the highest packing density and are more effective in preventing anodic oxidation of the underlying substrate. Voltammetry, X-ray photoelectron spectroscopy, and atomic force and fluorescence microscopy are utilized to interrogate the kinetic rates of biofunctionalization, the extent of surface coverage, monolayer quality, and the spatial selectivity of the process.

Alkenes↗