Histidine detection and signal amplification based on magnetic molecularly imprinted particle and Cu2+ coordination.

Magnetic molecularly imprinted (MMIP) particle-based electrochemical sensors are promising for wide detection applications. However, current sensing strategies mainly rely on electrochemical active analytes because of the lack of signal conversion and amplification methods. Herein, a novel histidine (His) sensor was designed based on MMIP particle and metal coordination of Cu2+ with His and cysteine (Cys). The whole determination processes were separated into recognition, coordination and detection steps. The target His in complicated samples can be selectively captured by the MMIP particles to ensure the specificity, then coordinated with Cu2+ and detected at magnetic electrodes under a specific condition to avoid contamination. Highly chemically stable MMIP particles can be prepared by the sol-gel method in large quantities at a very low cost. Additionally, the signal of Cu2+ can be significantly amplified using Cys modified Au nanoparticles. The optimized detection conditions were investigated by voltammetry. The sensor allowed His determination in a wide concentration range over 5-orders of magnitude with a low detection limit of 0.01 μM, which also expressed a promising performance in spiked water and serum samples. Accordingly, the proposed sensing strategy is beneficial for the design and preparation of novel MMIP particle-based electrochemical sensors. [Display omitted] • A novel His sensor was designed base on magnetic molecularly imprinted particle. • A promising signal amplification strategy was proposed with Cu2+ coordination. • The sensor showed a wide concentration range and low detection limit to His. • The excellent performance of the method decides its great application potential. [ABSTRACT FROM AUTHOR]