Plasmonic sensors for dengue virus detection: technological advances, challenges, future directions.

One of the major health concerns is the dengue virus, due to the steadily rising number of reported cases worldwide. Conventional diagnostic techniques, such as the NS1 antigen test, IgM detection, ELISA, and PCR have several limitations, including restricted sensitivity, cross-reactivity with other flaviviruses, and challenges in distinguishing between primary and secondary infections. While ELISA and PCR often require longer processing time, NS1 tests are valued for their speed but may show reduced sensitivity after one week. In contrast, plasmonic-based sensors offer advanced capabilities like label-free detection, real-time monitoring, and rapid on-site diagnosis. In recent decades, plasmonic research, including surface plasmon resonance (SPR), localized SPR and fiber optic SPR, has advanced considerably for dengue detection. This breakthrough offers a significant improvement in sensitivity, specificity, and miniaturization, making it suitable for practical deployment. This review explores dengue outbreaks, fundamentals of plasmonic sensors with their sensing mechanism, recent innovations, challenges, commercialization and future perspectives, aiming to bridge the gap between laboratory research and real-world applications.