SUPPLEMENTARY INFORMATION

Electrophoretically deposited CdS quantum dots based electrode for biosensor application

Hemant Dhyania, Md. Azahar Alib, M. K. Pandeyb, B. D. Malhotrab,c and P.Sena

aSchool of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067, India. Email: kashi.hemant@gmail.com; Tel: +911126738773 bDepartment of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India c

Department of Biotechnology,Delhi Technological University,Shabad Daulatpur, Main

Bawana Road, Delhi 11042, India

Fig.S1- Fluorescence of TGA capped CdS quantum dots.

Fig.S2- TEM images of dispersed and deposited CdS.

Fig. S3- Zeta potential plot of Methanol dispersed quantum dots.

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Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012

Fig S1- Fluorescence spectra of TGA capped CdS QDs when excited at the wavelength λext.=360 nm.

Fig.S2- (a) Elliptical granular structures seen in the TEM image of TGA capped CdS quantum dots dispersed in methanol (b) Granular structure obtained for the same CdS QDs dispersed in methanol (c) Lattice planes of the quantum dots are visible inside the boundaries of granular structures for TGA capped CdS QDs (d) Specific area diffraction pattern (SAED)

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012

obtained by focussing on granular structures (e) Hexagonal lattice diffraction pattern seen in SAED image of the TGA capped CdS QDs dispersed in methanol.

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Fig. S3- Zeta potential plot of the methanol dispersed TGA capped CdS quantum dots, shows the average surface charge around +15 mV.

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2012