RSC Publishing


Publishing

 

Cover image for Lab on a Chip, select for current issue

Lab on a Chip

Microfluidic & nanofluidic technologies for chemistry, physics, biology, and bioengineering



Subscribers

Non-subscribers

Free access



Paper

Lab Chip, 2008, 8, 1460 - 1467, DOI: 10.1039/b803450h


Open micro-fluidic system for atomic force microscopy-guided in situ electrochemical probing of a single cell

WonHyoung Ryu, Zubin Huang, Joong Sun Park, Jeffrey Moseley, Arthur R. Grossman, Rainer J. Fasching and Fritz B. Prinz


Ultra-sharp nano-probes and customized atomic force microscopy (AFM) have previously been developed in our laboratory for in situ sub-cellular probing of electrochemical phenomena in living plant cells during their photosynthesis. However, this AFM-based electrochemical probing still has numerous engineering challenges such as immobilization of the live cells, compatibility of the immobilization procedure with AFM manipulation of the probe, maintenance of biological activity of the cells for an extended time while performing the measurements, and minimization of electrochemical noise. Thus, we have developed an open micro-fluidic channel system (OMFC) in which individual cells can be immobilized in micro-traps by capillary flow. This system affords easy AFM access and allows for maintenance of the cells in a well-defined chemical environment, which sustains their biological activity. The use of micro-channels for making the electrochemical measurements significantly reduces parasitic electrical capacitances and allows for current detection in the sub-pico-ampere range at high signal bandwidths. The OMFC was further studied using simulation packages for optimal design conditions. This system was successfully used to measure light-dependent oxidation currents of a few pico-amperes from the green alga Chlamydomonas reinhardtii.

Graphical abstract image for this article  (ID: b803450h)