A hand-held in-situ nucleic acid detection device based on dual-function GHz acoustofluidic resonator.

Microfluidic-based nucleic acid testing (NAT) has been proven as an alternative approach for in-situ and rapid NA detection. However, these on-chip methods still require complex peripherals, which contradict the purpose of point-of-care (POC) applications. One of the major challenges is the integration of NA purification and amplification in a miniaturized setup with high mass and heat transfer efficiency. Here, we propose a hand-held in-situ nucleic acid detection device featuring a dual-functional GHz acoustofluidic resonator. The device is designed to utilize GHz acoustic streaming and acoustothermal effects to address both liquid mixing and heating issues, ensuring uniform reaction conditions and consistent thermal management in the microfluidic channel. By replacing traditional magnetic beads with polystyrene beads as matrix for solid-phase microextraction, the redundant washing and elution steps are eliminated, thereby simplifying the NA extraction process. The mixing and heating functions can be seamlessly switched by adjusting the applied power, thereby enhancing NA processing without the need for additional peripherals. The developed hand-held NAT apparatus achieved a detection limit of 10³ copies per milliliter in complex plasma samples within 35 min. Our method simplifies workflows, improves NA retention, and is suitable for processing complex biological samples, making it ideal for POC and in-field testing applications.