Homocysteine-Mediated Reactivity and Assembly of Gold Nanoparticles

• DOI: 10.1021/la062334t
• Publication Date: 2006-11-24T11:09:41Z
• Authors: I-Im S. Lim; Wui Ip; Elizabeth Crew; Peter N. Njoki; Derrick Mott; Chuan-Jian Zhong; Yi Pan; Shuiqin Zhou
• Keywords: Zwitterion; Reactivity; Thiol

This paper reports the findings of an investigation reactivity and assembly gold nanoparticles mediated by homocysteine (Hcys), a thiol-containing amino acid found in plasma. The aim is to gain insight into interparticle interaction reactivity, which has potential application for detection acids. By monitoring evolution surface plasmon resonance absorption dynamic light scattering presence Hcys, was shown be dependent on nature concentration electrolytes, reflecting effective screening diffuse layer around initial citrate-capped that decreases barrier Hcys adsorption onto surface, subsequent Hcys-capped facilitate zwitterion-type electrostatic interactions between groups bound different nanoparticles. A key element finding zwitterion Hcys−Au system much stronger than expectation simple or Au solution, new phenomenon originating from unique nanoscale interaction. strength reversibility are evidenced slow disassembly upon increasing pH at ambient temperatures its acceleration elevated temperature. These provide precise control interfacial reactivities acids anchored have broad implications development colorimetric nanoprobes