Large-scale nanopatterning of single proteins used as carriers of magnetic nanoparticles

TLDR: A variety of methods based on Coulomb-force-directed assembly of nanoparticles have been proposed, but the supramolecular organization attained from the ‘‘bottom-up’’ approaches either does not allow accurate placement of the desired structures on a specific region of an inhomogeneous surface.

Abstract: However, the supramolecular organization attained from‘‘bottom-up’’approachesiseitherdifficulttoextendfromnano-tomesoscopic length scales or does not allow accurate placement ofthe desired structures on a specific region of an inhomogeneoussurface. Similarly, a variety of methods based on Coulomb-force-directed assembly of nanoparticles have been proposed.

Figures

Fig. 2: Patterning of ferritin molecules over cm 2 areas by controlled dewetting and surface functionalization at neutral pH values.

Fig. 1: Patterning of ferritin molecules by local oxidation nanolithography and silicon functionalization by APTES at low pH values.

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NanoSpain2010 23-26 March, 2010 Malaga-Spain
Large-scale nanopatterning of single proteins used as carriers of magnetic nanoparticles
Ramsés V. Martínez, Javier Martínez, Marco Chiesa, Ricardo García
Instituto de Microelectrónica de Madrid, CSIC, Isaac Newton 8, 28760 Tres Cantos, Madrid
(Spain)
mchiesa@imm.cnm.csic.es
Accurate and reproducible patterning of proteins and functional nanoparticles is essential to
exploit their properties in nano and microscale devices [1]. Electrostatic interactions, capillary
forces, surface functionalization and nanolithography can be used in combination or
independently to achieve the desired protein organization [2]. Here, we report a simple yet
efficient method to deposit ferritin proteins with nanoscale accuracy over large areas. The
selective deposition is driven by the electrostatic interactions existing between the proteins
and nanoscale features. The efficiency of the deposition process can be controlled by
changing the pH of the solution. By combining a top-down tip-based nanolithography [3] and
bottom-up electrostatic interactions we have formed regular arrays of ferritin molecules with
an accuracy that matches the protein size (~10 nm). Magnetic force measurements confirm
the magnetic activity of the deposited nanoparticles.
References:
[1] W. Cheng, T. Walter, D. Luo et al., Nature Nanotechnology 3 (2008) 682.
[2] R.V. Martinez, R. Garcia, E. Coronado et al., Adv. Mater. 19 (2007) 291.
[3] R.V. Martínez, J. Martínez, M. Chiesa et al., Adv. Mater. DOI: 10.1002/adma.200902568
Figures:
Fig. 1: Patterning of ferritin molecules by local oxidation nanolithography and silicon functionalization by
APTES at low pH values.
Local Oxidation
pH 3
APTES
Ferritin deposition
Si
250 nm
25 nm
Oral

NanoSpain2010 23-26 March, 2010 Malaga-Spain
Fig. 2: Patterning of ferritin molecules over cm
2
areas by controlled dewetting and surface functionalization at
neutral pH values.
PDMS stamp
Controlled dewetting
Liquid film
Pattern
replication
APTES
pH 6.5
5 µm
10
nm
500 nm
Oral