Bioassembled Nanocircuits of Mo₆S_9−<i>x</i>I_<i>x</i> Nanowires for Electrochemical Immunodetection of Estrone Hapten

Abstract

We demonstrate a novel and highly sensitive electrochemical detection of estrone based on an immunosensor platform, composed of bioassembled nanocircuits of Mo 6S 9- x I x nanowires (MoSI NWs) covalently connected to anti-estrone antibodies. The one-step, label-free, and quantitative detection of estrone is realized by employing the [Ru(NH 3) 6] (3+/2+) redox ions to sense anti-estrone antibody and estrone interactions. The MoSI NWs/anti-estrone antibody nanocircuit architectures provide an amplification and conductive pathway for the specific electrochemical sensing of estrone hapten. A detection limit of 1.4 pg x mL (-1) was achieved in contrast to previous electrochemical techniques in which the sensitivity was limited to the nanomolar range.