Rapid and accurate detection of crop viruses by nano-electrochemical sensors.

This review aims to critically examine the development, capabilities, and future prospects of nano-electrochemical sensors as a next-generation solution for the rapid and accurate detection of crop viruses. The motivation stems from the urgent need to overcome the shortcomings of conventional diagnostic tools-such as ELISA and PCR-which, while accurate, suffer from drawbacks in speed, portability, and adaptability to evolving viral threats. We first introduce the fundamental architecture and working principles of electrochemical biosensors, emphasizing key transduction mechanisms including amperometry, voltammetry, and electrochemical impedance spectroscopy. A major focus is placed on the role of nanomaterials-such as gold nanoparticles, carbon-based nanostructures, quantum dots, metal-organic frameworks (MOFs), and MXenes-in enhancing sensor performance through improved surface area, electron transfer, and bioreceptor immobilization. Real-world applications are highlighted through recent advances in detecting agriculturally important viruses like tobacco mosaic virus, plum pox virus, and Citrus tristeza virus, with emphasis on sensitivity, selectivity, and response time. The review also explores current limitations, such as sensor reproducibility, field stability, and biofouling, as well as emerging directions including multiplexed detection systems and integration with Internet of Things (IoT) networks and artificial intelligence (AI) platforms for real-time crop health monitoring. By synthesizing technological advances and outlining actionable research pathways, this review underscores the transformative potential of nano-electrochemical sensors in plant virology and precision agriculture.