I I n n t t e e r r n n a a t t i i o o n n a a l l J J o o u u r r n n a a l l o o f f C Ch h e e m mi i c c a a l l a a n n d d N Na a t t u u r r a a l l S S c c i i e e n n c c e e Vol. 3, No. 3 (2015): 269-274 Research Article Open Access ISSN: 2347-6672 Electric Field Effect on the Synthesis of Nanogold Particles by PLAL Raad M.S.Al-Haddad 1 , Mazin K. Hamid 2 * and Thamir Jumaa 3 1 Department of Physics, College of Sciences, Baghdad University, Baghdad, Iraq. 2 College of medicine, Al-Nahrain University, Baghdad, Iraq. 3 Department of Physics, College of Sciences, AL-Nahrain University, Baghdad, Iraq. * Corresponding author: Mazin K. Hamid; email: mazin_kamil2002@yahoo.com ABSTRACT Gold nanoparticles (AuNPs) were synthesized by pulse laser (Nd:YAG, λ = 1064 nm) ablation of a gold target immersed in deionized water by300mJ of laser energy and 100 laser shots (pulses) with a D.C electrical field was applied above the target with adjusted voltage (1,2,3,4,5,10,15,20,25,30) Volt brought by two aluminum quadrate parallel-electrodes with 2cm apart, It is clearly shown from UV-visible absorption spectra with aid of TEM images that at different values of applied external D.C electric field the gold nanoparticles shows different SPR peaks and FWHM ,and as it is shown from the results can be deducted that the gold nanoparticles produced possess different sizes and different shapes , At low values of electric field (0.5- 1V/cm) the nanogold particles have spherical, small average size of (10-18) nm and low concentration . When electric field proceeds with value of (2-10V/cm) a variety of shapes like nanocubes, nanospindles, rhombic and triangles have appeared besides the spherical gold nanoparticles with relatively large concentration. In addition the spherical nanoparticles possess larger size than that at low values of electric field (0.5- 1V/cm) ,otherwise at electric field value of >10V/cm) the size of this spherical nanogold would be decreased and its concentration increases until all irregular shapes diminish and the spherical nanogold particles become the predominant shape with relatively small size. Keywords: Gold nanoparticles, Surface Plasmon resonant, Electric field, Irregular shapes. 1. INTRODUCTION Compared to bulk materials, nanoparticles (NPs) have peculiar optical, 1 electrical, 2 and magnetic properties 3 which allow novel applications in various fields including electronics, 4 sensors, 5,6 solar cells, 7 functional textiles, 8 and paints. 9 Also, they are widely used in biomedical field such as medicine, 10,11 imaging, 12 and therapy. 13 In particular, their surface plasmon frequencies in visible region 14,15 are certainly strong advantages over the others., It has been demonstrated that stable colloids containing nano-size metal particles are prepared by laser ablation of metal targets in aqueous solutions 16–33 . Advantages of this colloid preparation method compared to chemical synthesis are simplicity of the procedure and absence of chemical reagents in solution. The intrinsic properties of a metal nanoparticle are mainly determined by its size, shape, composition, crystallinity, and structure. In principle, one could control any one of these parameters to fine-tune the properties of this nanoparticle. Moreover, recent researches have been revealed that size of colloidal particles significantly depends on the laser parameters for ablation. For example, particle size decreased with decrease in laser wavelength 26, 27 . Size of colloidal particles prepared by using femtosecond pulse lasers was smaller than that prepared by using nanosecond- pulse lasers 28, 32, 33 . These facts suggest that control of particle size, which is an important property of colloids, will be possible with laser `ablation in liquids. Controlling the size, shape, and structure of metal nanoparticles is technologically important because of the strong correlation between these parameters and optical, electrical, and catalytic properties.in this work we used laser ablation in deionized water with applying DC electric field to produce gold nanoparticles. Received: 05 March 2015 Accepted: 25 April 2015 Online: 11 May 2015 http://ijcns.aizeonpublishers.net/content/2015/3/ijcns269-274.pdf 269