Method of bonding gold nanoparticles with diethylenetriamine pentaacetic acid

A method of bonding gold nanoparticles (GNPs) with diethylenetriamine pentaacetic acid (DTPA), comprising steps of:

• (a) dissolving 1 mL±10% of 0.1M of gold chloride (HAuCl4) in 500 mL±10% of ultrapure water;
• and adding 10 mL±10% of sodium borohydride (NaBH4) with stirring to obtain a solution of GNPs;
• (b) preparing 1 mL±10% of bovine serum albumin (BSA) solution with deionized water;
• adding the BSA solution to 2 mL±10% of said solution of GNPs with stirring to adhere BSA on surfaces of said GNPs;
• and purifying the mixed BSA and GNPs solutions to obtain a liquid phase of a phosphate buffer;
• and
• (c) reacting 50 mg±10% of BSA in 0.1M of a carbonate-bicarbonate buffer with 1 mg±10% of diethylenetriamine pentaacetic acid (DTPA) in solution with a volume of 1 mL;
• then processing a first purification to obtain an initially purified product;
• then adding the initially purified product to 2 mL of said solution of GNPs and reacting the mixture;
• and secondarily purifying the mixture again such that the liquid phase is changed into a phosphate buffer.