writer：Youju Huang, Palanisamy Kannan, Lei Zhang, Tao Chen* and Dong-Hwan Kim*
keywords：Concave Gold NPs, Electrochemical Sensor, IgG Immunobiosensor
source：期刊
specific source：RSC Advance, 2015, 5, 58478-58484
Issue time：2015年
we report a novel electrochemical sensor for the label-free, real time and highly sensitive detection of antibody-antigen interactions based on concave gold nanocuboids (CAuNCs). In contrast to low-index facets AuNPs such as gold nanorods (AuNRs), the CAuNCs provide higher surface atoms with enhanced chemical activities, which can efficiently catalyse the oxidation reaction of amino groups on antibody (Anti-bovine IgG produced in rabbit). This leads to an obvious redox current response was observed in cyclic voltammetry (CV) measurement. Upon the introduction of IgG antigen, notable decrease of anodic peak current was observed, which is attributed to the decrease of exposed amino groups after antibody-antigen interactions. The unique electro-catalytic property of CAuNCs allows to easily detecting the rabbit IgG antigen in a wide range of concentration (from 10 to 200 ng mL-1) with a limit of detection (LOD) to 5 ng mL-1 by using CV method.