Organophosphonic Acid-Regulating Assembly of PV-SbIII Polyoxotungstate and Its Potential in Building a Dual-Signal Readout Electrochemical Aptasensor for Carcinogen Detection.

Abstract

Template-directed assembly of giant cluster-based nanomaterials is an everlasting theme in cluster science. In this work, ethylenediamine tetramethylphosphonic acid [H8EDTPA = (POCH2(OH)2)4C2H4N2] and [B-α-SbW9O33]9- were, respectively, used as an organic template and an inorganic template to prepare an organophosphonic acid-regulating PV-SbIII-heteroatom-inserted polyoxotungstate aggregate [H2N(CH3)2]5Na11H9[CeW4O10(HEDTPA)SbW15O50][B-α-SbW9O33]2·36H2O (1). Noteworthily, organophosphonic acid ligand not only works as an organic template leading to the assembly of a [HEDTPASbW15O50]14- building block but also further bridges the sandwich-type [CeW4O10(B-α-SbW9O33)2]11- entity. To extend its potential application in electrochemical sensing properties, we prepared a three-dimensional 1@EGO composite (EGO = reduced graphene oxide functionalized by ethylenediamine) with porous architecture and a prominent conducting ability. Furthermore, the 1@EGO composite was explored as a modification material for glassy carbon electrodes to build a dual-signal readout electrochemical aptasensor for carcinogens, which shows much better detection performance for aflatoxin B1 compared with traditional single-signal biosensors.