Congratulations to the Microfluidics Cluster UPV/EHU team for a new publication in Microchemical Journal !!: “Colorimetric detection and quantification of the stress-associated microRNA408 in tomato leaf extracts through RNAzymes in a paper-based microfluidic device”

A bit of Background: Early detection of stress mediators in crops is essential to prevent losses and support sustainable food production. MicroRNAs (miRNAs) regulate stress responses by modulating gene expression, making them valuable biomarkers. RNAzymes—catalytic RNA molecules—can be engineered to bind specific miRNAs and generate a colorimetric signal. Here, we present a hybrid paper/plastic device that uses RNAzyme-based sensors for the detection of stress mediators in plants, developed in collaboration with the Institute for Integrative Systems Biology (I²SysBio), Valencia, Spain.

Main Results: RNA Sensing Probes were designed for miRNA408, a key stress marker, using tomato as a model. After validation in solution, the sensor was transferred to a wax-ring paper platform. The addition of miRNA408 reduced signal intensity in a concentration-dependent manner, with detection limits of 233 ng in solution (25 min) and 43 ng on paper (9 min). Integrated into a paper-based microfluidic device, the system detected synthetic miRNA408 (640 ng) in both water and tomato leaf extract within 9 min after starting the detection reaction.

The Significance: These findings represent the first RNAzyme-based paper technology for miRNA detection in crops, offering farmers digital, on-site decision-making tools. Results aid in advancing the understanding of stress response mechanisms in tomato and, potentially, in other species.

Many thanks to all the amazing team; Nicolas Nazar, Stefania Pellegrini, Enrique Azuaje-Hualde, Xabier Arciniega, Pablo E. Guevara-Pantoja, M. Carmen Marqués, Francesca Longo, Gustavo Gomez, Lourdes Basabe-Desmonts and Fernando Benito-Lopez, for making this possible.

Link to the paper: https://www.sciencedirect.com/science/article/pii/S0026265X25024968?via%3Dihub 

Link to the Journal’s webpage: https://www.sciencedirect.com/journal/microchemical-journal