Manganese(II) phosphate nanoflowers as electrochemical biosensorsfor the high-sensitivity detection of ractopamine

We report a novel kind of electrochemical biosensor based on Mn-3(PO4)(2)-like nanoflowers for detecting ractopamine. Mn-3(PO4)(2)-protein hybrid nanocomposites were synthesized by self-assembly method, in which proteins such as immunoglobulin G (IgG), bovine serum albumin (BSA), and ractopamine antibody (RAC(anti)) play an important role in the production of nanoflowers. To evaluate the efficiency of different biosensors based on Mn-3(PO4)(2)-like nanoflowers, three kinds of nanocomposites were prepared, i.e., thenanocomposite of Mn-3(PO4)(2) and IgG (Mn-3(PO4)(2)@IgG), RAC(anti)(Mn-3(PO4)(2)@RAC(anti)), and BSA together with Au nanoparticles (Mn-3(PO4)(2)@BSA@ AuNPs). Different detection approaches were designed andcarried out for varied biosensors. Mn-3(PO4)(2)@BSA@AuNP and Mn-3(PO4)(2)@ RAC(anti) nanocomposites were used as the sensitive layer of the electrochemical biosensor for RAC detection. However, only after RAC(anti) adsorption onto the Mn-3(PO4)(2)@ IgG nanocomposite surface, the developed electrochemical biosensor was applied to detect ractopamine. Results showed that these Mn-3(PO4)(2)-like nanoflowers exhibited high chemical activity and good electrochemical performance. All ractopamine detection procedures were determined by electrochemical measurements, providing extremely low detection limits of 9.32,4.6, and 26 pg mL(-1) for three kinds of nanoflowers. Therefore, Mn-3(PO4)(2)-like nanoflowers could also be utilized as electrochemical biosensors for various detection procedures in different fields. (C)2015 Elsevier B.V. All rights reserved.