Multimodal optical properties of hybrid complexes of single walled carbon nanotubes and colloidal semiconductor quantum dots

 

 

 

Hyeonggon Kang1, Matthew L. Clarke1, Zhenping Zhou2, Jianyong Tang1, John T. Woodward1, Tinh Nguyen2, and Jeeseong Hwang1

 

1Optical Technology Division, Physics Laboratory, NIST, Gaithersburg, MD, USA

2 Materials and Construction Research Division, Building and Fire Research Laboratory, NIST, Gaithersburg, MD, USA



The need for technologies enabling hybrid nano-device assemblies using assorted nano-material building blocks has been paramount for the last decade in a variety of fields such as optoelectronics, nanooptics, advanced telecommunication engineering, and nanomedicine. Such nanoscale building blocks include metal nanoparticles such as gold or silver nanospheres, rods and shells, carbon nanotubes (CNTs), semiconductor nanocrystals or quantum dots (QDs), and organic linker molecules such as DNA and antibody-antigen pairs. The ultimate purpose of engineering these hybrid devices is to achieve desired functions through the assembly of nanoscale building blocks. Their functions are usually dependent upon the nanoscale details of their assembly structures, which can be characterized by optical measurement techniques capable of enhanced spatial resolution beyond the diffraction limit. On the other hand, an integrated approach employing diffraction-limited spectroscopic imaging techniques and time-resolved measurements provide rich information on the interactions among the different building blocks. Although the spatial resolutions of these imaging techniques are diffraction-limited, the synergistic employment of the techniques allows assessment of nanoscale structural information. Here, we demonstrate the capability of integrated diffraction-limited imaging techniques to reveal nanoscale details in hybrid assemblies of fluorescent colloidal QDs and single walled carbon nanotubes (SWCNTs). SWCNTs were wrapped by 30-mer amine-terminated single-strained DNA molecules, and carboxylated CdSe/ZnS QDs were added to the DNA wrapped SWCNTs by forming the peptide bonding between QDs and DNA molecules. These complex samples were analyzed by integrated multimodal imaging techniques including confocal fluorescence spectroscopic and lifetime microscopy, polarization dependent confocal Raman microscopy, and atomic force microscopy. This analysis revealed rich nanoscale information on the distribution of each element and the assembly structure. Especially, the nanoscale proximity between QDs and CNTs in the complex resulted in significant reduction of the fluorescence lifetime of QDs bound to SWCNTs.

 

Author information:

 

Name     :      Hyeonggon Kang

Mentor   :      Jeeseong Hwang

Division :      Optical Technology Division

Bldg/Room:  216/B217

Mail stop:     8443        

Phone :         301-975-8547

Fax :             301-975-6991

E-mail :        hyeong.kang@nist.gov

Sigma Xi :   not a member

Poster Category :  Materials