Preferential cell attachment to nitrogen-doped diamond-like carbon (DLC:N) for the measurement of quantal exocytosis

Abstract

Electrochemical measurement of transmitter or hormone release from individual cells on microchips has applications both in basic science and drug screening. High-resolution measurement of quantal exocytosis requires the working electrode to be small (cell-sized) and located in immediate proximity to the cell. We examined the ability of candidate electrode materials to promote the attachment of two hormone-secreting cell types as a mechanism for targeting cells for to recording electrodes with high precision. We found that nitrogen-doped diamond-like carbon (DLC:N) promoted cell attachment relative to other materials tested in the rank order of DLC:N > In2O3/SnO2 (ITO), Pt > Au. In addition, we found that treating candidate electrode materials with polylysine did not increase attachment of chromaffin cells to DLC:N, but promoted cell attachment to the other tested materials. We found that hormone-secreting cells did not attach readily to Teflon AF as a potential insulating material, and demonstrated that patterning of Teflon AF leads to selective cell targeting to DLC:N “docking sites”. These results will guide the design of the next generation of biochips for automated and high-throughput measurement of quantal exocytosis.

Nanocrystalline diamond microelectrode arrays fabricated on sapphire technology for high-time resolution of quantal catecholamine secretion from chromaffin cells

“…It is more transparent than boron-doped NCD and works nicely in the anodic regime (Sun and Gillis, 2006). However, ITO shows a lower chemical stability, especially at acidic pH and cathodic potentials, and a narrower potential window with respect to the ∼3 V of boron-doped NCD electrodes (Sun and Gillis, 2006;Chen et al, 2008;Sen et al, 2009). …”

Quantification of noise sources for amperometric measurement of quantal exocytosis using microelectrodes

“…Therefore carbon-fiber electrodes are pressed gently to the surface of the cell whereas it is desirable for cells to tightly adhere to planar electrodes so they do not wash away upon solution exchange 13–14 . Gleixner and Fromherz 31 measure the sheet resistance (R sheet ) between adherent cells and a fibronectin-coated silica substrate to be ~10 MΩ in physiological bath solution.…”

Spatially Controlling Neuronal Adhesion and Inflammatory Reactions on Implantable Diamond

“…Our findings provide evidence that reducing inflammatory cell adherence using antifouling coatings, like pHEMA, can reduce the accumulation of glia surrounding devices implanted into the CNS. Whilst, other studies have reported similar low levels of inflammatory cell adherence (monocytes and macrophages) using antifouling agents [8,25,36], we have presented the additional possibility of spatially controlling this effect using our micropatterned PEG surfaces. We believe that by doing so, we can tailor implants that make use of the beneficial effects of the foreign body response (e.g.…”

“…Diamond-based coatings have also been shown to improve haemocompatability (by reducing activation of the coagulation cascade, platelets and inflammatory cells) [18][19][20][21][22][23]. Furthermore, diamond and DLC can be modified with dopant materials to alter their mechanical, chemical, electrical and biological properties [24][25][26][27][28][29]. For example, boron-doping vastly increases the electrical conductivity of diamond, making it more suitable for electrode applications [24].…”