A method for regenerating gold surface for prolonged reuse of gold-coated surface plasmon resonance chip.

We developed a method to completely regenerate the gold (Au) surface of 3-aminopropyltriethoxysilane (APTES)-functionalized Au-coated surface plasmon resonance (SPR) chip that had been used for human fetuin A (HFA) immunoassay. It involved treatment of the used SPR chip with freshly prepared piranha solution (concentrated H(2)SO(4)/30% H(2)O(2)=3:1, v/v) for 15 min followed by extensive rinsing with ethanol and deionized water. The developed method enabled prolonged reuse of the regenerated SPR chip that increased its cost-effectiveness without affecting the reproducibility of HFA immunoassays.