Nanosensors

Hyunkyung BaeByungmook Kim

Nanosensors

Why is it needed?

How to make?

What to do?

Big Issues in Biology

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Properties of Nanosensors

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1. Magnetic Property 2. Optical property

Magnetic properties

Ferromagnetism Paramagnetism. Ferrimagnetism Antiferromagnetism

Ordered and same magnitude without external magnetic field

Disordered without external magnetic fieldIn the external mag-netic field, the mo-ments are ordered.

Aligned oppositely with different magni-tude

Aligned oppositely with the same magni-tudes

Superparamagnetism

• Superparamagnetism is a form of magnetism, which appears in small ferromagnetic or ferromagnetic nanoparticle.

• Neel relxation time < measurement time→average zero magnetic state = superparamagnetic state

• When an external magnetic field is applied to an assembly of superparamagnetic nanoparticles, their magnetic moments tend to align along the applied field, leading to a net magnetization.

N S

Nanoparticle

Optical properties

IGOR L. MEDINTZ1*, H. TETSUO UYEDA2, ELLEN R. GOLDMAN1 AND HEDI MATTOUSSI, Quantum dot bioconjugates for imaging, labelling and sensing, Nature materials 2005

Alexa 488

FITC

GFP Quantum dots

Organic dye

0 10 20 30 40 50 60 70 80 90100

110120

130140

1500

0.2

0.4

0.6

0.8

1

1.2

Photobleaching time

FITC Alexa Flour 488GFP QD 608

Time(sec)

Rela

tive

inte

nsity

Qd is Much Much stable!

Fluorescence Resonance Energy Transfer

How can we make it?

Characterization

Gold nanoparticle – Optical Dark field

Quantum dots - TIRF

What can we do with it?

1.Cell/Protein Imaging2.Cell/Protein Manipulation3.Nano ruler

1. Cell/Protein Imaging

40mer

lipid

63mer

82mer

Lipid

2. Cell/Protein Manipulation

Cell

Channel

3. Nanoruler

• Alexander J. Mastroianni, David A. Sivak, Phillip L. Geissler, and A. Paul Alivisatos, Probing the Conformational Distributions of Subpersistence Length DNA, Biophysical Journal 2009

.

3. Nanoruler

• Alexander J. Mastroianni, David A. Sivak, Phillip L. Geissler, and A. Paul Alivisatos, Probing the Conformational Distributions of Subpersistence Length DNA, Biophysical Journal 2009

.

Dark Field – Gold nanoparticles TIRF Microscopy – Quantum dots

Q dot

Magnetic+Au

Completely matching!

Glass

Strong magnet

TIRF Microscopy

Strong magnet

Future work

References• A.P.Alivisatos, Science, New Series, Vol. 271, No. 5251. (Feb. 16, 1996), pp. 933-937• Yadong Yin & A.Paul Alivisatos, NATURE04165, vol 437, 2005• J. M. Yuk, J.W. Park, A. Paul Alivisatos, High-resolution EM of Colloidal Nanocrystal growth using graphene liquid cells, Science 336, 61 (2012) • J. M. Yuk, J.W. Park, A. Paul Alivisatos, High-resolution EM of Colloidal Nanocrystal growth using graphene liquid cells, Science 336, 61 (2012) • Xiaogang Peng, L.Manna, W.Yang, J. Wickham, E.Scher, A.Kadavanich & A.P.Alivisatos, Shape control of CdSe nanocrystals, Nature,vol 404, 2 March 2000• L.Manna, D.J.Milliron, A.Meisel, E.C.Scher, A.Paul Alivisatos, Controlled growth of tetrapod-branched inorganic nanocrystals, nature materials, vol 2,June 2003• Haitao Liu and A.Paul Alivisatos, Preparation of Asymmetric Nanostructures through Site Modification of Tetrapods,Nano Lett., Vol. 4, No. 12, 2004 • Son, D. H.; Hughes, S. M.; Yin, Y. D.; Alivisatos, A. P., Cation exchange reactions-in ionic nanocrystals. Science 2004, 306, (5698), 1009-1012• Robinson, R. D.; Sadtler, B.; Demchenko, D. O.; Erdonmez, C. K.; Wang, L. W.; Alivisatos, A. P., Spontaneous superlattice formation in nanorods through partial cation exchange. Science 2007, 317, (5836), 355-358• IGOR L. MEDINTZ1*, H. TETSUO UYEDA2, ELLEN R. GOLDMAN1 AND HEDI MATTOUSSI, Quantum dot bioconjugates for imaging, • labelling and sensing, Nature materials 2005• Alexander J. Mastroianni, David A. Sivak, Phillip L. Geissler, and A. Paul Alivisatos, Probing the Conformational Distributions of Subpersistence Length DNA, Biophysical Journal 2009