Magnetism based electrochemical immunosensor for chiral separation of amlodipine

- Enantioselective immunogen and S-amlodipine specific antibody were prepared.
- A magnetism based immunosensor was assembled.
- S, R-amlodipine could be purely separated and collected from racemic amlodipine.
- Captured S-amlodipine could be accurately quantitated with a LOD of 0.04 ng mL−1.
- The magnetism based immunosensor is simple, reliable and multi-functional.

Amlodipine is one of the most important anti-hypertension agents and S-amlodipine is 1000 folds more efficient than R-amlodipine. However, chiral separation of amlodipine remains a challenge. Here we present an effective strategy for chiral resolution of amlodipine using anti-S-amlodipine antibody for ultra-specific capture and magnetic beads for convenient collecting. The collected enantiomers are ultra-pure based on the chiral HPLC identification. Simultaneously, the captured S-amlodipine could be quantitatively detected with a linear range from 0.1 to 1000 ng mL−1 (R2 = 0.9937), along with a limit of detection of 0.04 ng mL−1. The advantages of the developed magnetic electrochemical biosensor for amlodipine include specific chiral separation, sensitive quantitation, easy-to-operate procedures and time-saving protocols. This method is demonstrated as a novel tool for highly confident separation and quantification of amlodipine enantiomers, in this study. The magnetic biosensor may open up new avenues for intensive study of amlodipine enantiomers and thus be potential in clinical pharmacy and pharmacokinetics studies.

86