A dual-mode colorimetric and electrochemical strategy for sensitive detection of PRRSV using imidazole-copper...

Porcine reproductive and respiratory syndrome virus (PRRSV) is highly contagious and potentially lethal, and has become a major threat to the global pig industry. The frequent mutation of the virus has limited the effectiveness of existing vaccines and control measures, posing great challenges to epidemic prevention and control. Therefore, there is an urgent need to develop more sensitive and field-applicable detection technologies to address this increasingly severe situation. In this context, establishing efficient, accurate, and adaptable detection methods will play a crucial role in enabling early intervention and precise epidemic management.

This paper proposes a dual-mode highly sensitive detection platform based on imidazole-copper (I-Cu) nanozymes, aiming to achieve rapid and stable recognition of PRRSV. In this method, the structurally stable and conserved nucleocapsid protein (N) in PRRSV was targeted, and a dual-antibody recognition mechanism was constructed using a PRRSV-specific nanobody (Nb2) and a polyclonal antibody (Ab1). On this basis, the superior laccase-like activity of I-Cu nanozymes was integrated with its electrochemical properties to develop a dual-mode biosensing system integrating colorimetric and electrochemical detection. The experimental results show that the minimum detection limit of this method is 3.8 pg mL^-1 in the colorimetric mode and 1.5 pg mL^-1 in the electrochemical mode, demonstrating excellent detection performance. The recovery rate and RSD in artificial serum samples both fell within acceptable ranges, demonstrating the reliability of this method in complex matrices. Finally, the feasibility of the dual-mode sensor was verified using actual samples, and the electrochemical biosensor demonstrated higher stability and accuracy.

This study successfully developed a colorimetric-electrochemical sensor for the dual-mode detection of PRRSV. The system allows for intuitive judgment through colorimetric reading and enhances detection sensitivity with electrochemical signals. It offers significant advantages, such as no need for nucleic acid extraction, ease of operation, fast response, and high stability. Therefore, the dual-mode sensor has potential application value in animal disease early warning and biosafety monitoring.