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

• Mn3(PO4)2–protein hybrid nanocomposites prepared by self-assembly method.
• Highly sensitive detection of ractopamine based on the electrochemical biosensor of Mn3(PO4)2–protein hybrid.
• The detection limits in pg mL−1 range have been obtained.

We report a novel kind of electrochemical biosensor based on Mn3(PO4)2-like nanoflowers for detecting ractopamine. Mn3(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 (RACanti) play an important role in the production of nanoflowers. To evaluate the efficiency of different biosensors based on Mn3(PO4)2-like nanoflowers, three kinds of nanocomposites were prepared, i.e., the nanocomposite of Mn3(PO4)2 and IgG (Mn3(PO4)2@IgG), RACanti (Mn3(PO4)2@RACanti), and BSA together with Au nanoparticles (Mn3(PO4)2@BSA@AuNPs). Different detection approaches were designed and carried out for varied biosensors. Mn3(PO4)2@BSA@AuNP and Mn3(PO4)2@RACanti nanocomposites were used as the sensitive layer of the electrochemical biosensor for RAC detection. However, only after RACanti adsorption onto the Mn3(PO4)2@IgG nanocomposite surface, the developed electrochemical biosensor was applied to detect ractopamine. Results showed that these Mn3(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, Mn3(PO4)2-like nanoflowers could also be utilized as electrochemical biosensors for various detection procedures in different fields.

A novel kind of electrochemical immunosensor array based on Mn3(PO4)2-like nanoflowers for detecting ractopamine (RAC) was reported. Compared with routine methods, the present work shows two advantages. The first is the presence of RACanti within the nanoflower-like structures to further immobilize ractopamine directly. The other advantage is that the nanoflower structure of the nanocomposites with high specific surface area provides sufficient active sites for attaching ractopamine.Figure optionsDownload as PowerPoint slide