the growth of hippocampal neurons. Fig. 4C clearly shows the
contrast between electrochemically stimulated and non-stimulated
regions, which are found in the lower and upper parts of the
boundary, respectively. Although the entire surface of both the
activated and non-activated areas had been exposed to linker
and peptide solutions, hippocampal neurons grew only in the
activated area. Importantly, the selective spatial control of
neuronal growth on the desired surface pattern has a special
meaning in terms of recent studies on artificial neural networks,
based on surface-patterned neurons14 and the nano-interface
between neurons and electrodes.15 The proposed method
allows for the culturing and patterning of neurons on a desired
surface with an electrochemically addressable dimension,
possibly as small as the sub-micron level.
In summary, we suggest herein a new molecular scheme for
site-selective protein immobilization and cell patterning on the
basis of electrochemical azo-cleavage. The proposed system
offers valuable advantages including a reductive cleavage
mechanism that is free from the oxidation of electrode
surfaces, and the generation of an amine surface favorable
for immobilization of biomolecules. It should be noted that
the reductive cleavage strategy is useful with silicon surfaces,
where patterning strategies should be applied for more
sophisticated applications.
This work was supported in part by the Korea Science and
Engineering Foundation (KOSEF) grants funded by the Korea
government (MEST) (No. R11-2007-012-02002-0(2009)), by
the grant from the Industrial Source Technology Development
Program (10033657) of the Ministry of Knowledge Economy
(MKE) of Korea, and the Nano/Bio Science & Technology
Program (M10536090001-05N3609-00110) of the Ministry of
Education, Science and Technology (MEST), South Korea.
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Fig. 4 Hippocampal neuronal cells two days after seeding on the
TEG-tethered azobenzene surface (A), on the electrochemically
activated and then CGG-IKVAV conjugated surface (B). (C)
Comparison in one chip between just the 2-coated surface and
electrochemically stimulated region. By immersing part of the 2-coated
gold surface into the electrolytic solution, only the region dipped in the
solution was electrochemically activated; it was there that the neuronal
cells later adhered and grew. The black solid line is the meniscus of the
solution, which serves as a boundary between the electrochemically
activated and non-activated regions.
ꢀc
This journal is The Royal Society of Chemistry 2010
Chem. Commun., 2010, 46, 3863–3865 | 3865