Synthesis of gold nanoparticles using red algae extract

Abstract

A method for preparing gold metal nanoparticles, e.g., nanospheres and nanoprisms, includes combining an extract of red algae with chloroauric acid (HAuCl 4 ). The red algae can be Laurencia papillosa . The extract can include a water solvent extract. The chloroauric acid (HAuCl 4 ) can be in an aqueous solution. The method can include providing chloroauric acid (HAuCl 4 ), providing a red algae extract, and combining the chloroauric acid (HAuCl 4 ) and the red algae extract to produce gold nanoparticles.

We claim: 
     
         1 . A method of synthesizing gold nanoparticles using red algae extract comprising:
 providing a solution of chloroauric acid (HAuCl 4 );   providing an aqueous solution of red algae extract, and   combining the solution of chloroauric acid (HAuCl 4 ) and the red algae extract solution to produce gold nanoparticles.   
     
     
         2 . The method of synthesizing gold nanoparticles using red algae extract according to 
     
     
         1 . , wherein the red algae extract comprises an extract of Laurencia papillosa. 
     
     
         3 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the solution of chloroauric acid (HAuCl 4 ) includes a chloroauric acid (HAuCl 4 ) concentration of about 0.25 mM to 5.0 mM. 
     
     
         4 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the gold nanoparticles include gold nanospheres. 
     
     
         5 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein a concentration of the red algae extract is from about 0.01 to about 0.10 g/mol. 
     
     
         6 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the gold nanoparticles have a mean diameter in the range of from about 1 to about 100 nm. 
     
     
         7 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the gold nanoparticles have a mean diameter in the range of from about 1 to about 55 nm. 
     
     
         8 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein a shape of the nanoparticles is at least one of spherical, spheroidal, elongated spherical, rod-shaped, and prismatic. 
     
     
         9 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the nanoparticles are nanoprisms. 
     
     
         10 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 1 , wherein the extract of red algae is prepared by a method including the steps of:
 pulverizing a quantity of dried red algae samples into small pieces;   boiling the pieces in water for about 5 minutes to about 10 minutes to provide a boiled extract solution; and   isolating the extract from the solution.   
     
     
         11 . The method of synthesizing gold nanoparticles using red algae extract according to  claim 10 , wherein the red algae is  Laurencia papillosa.    
     
     
         12 . The method of synthesizing gold nanoparticles using red algae according to  claim 11 , wherein the extract is isolated by centrifugation at about 5000 rpm for about five minutes at a temperature of about 5° C.