Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 150334

150334 - Photothermal Recycling Nanosensor for Continuous Biomolecular Monitoring 

Biosensors that continuously monitor circulating biomarkers have the potential to provide invaluable real-time insights into the physiological status and disease trajectory of patients. This is especially important for patients receiving intensive care, as their condition can change dramatically in a matter of hours or even minutes. Identifying unstable patients early and providing timely interventions is currently the most significant clinical challenge in hospital intensive care units. However, standard diagnostic methods rely on assays developed for use in clinical chemistry laboratories, which often involve time-consuming procedures and extended sample-to-result times. These conventional assays typically require significant reagent costs and large sample volumes for each measurement, rendering them impractical for frequent sampling and continuous monitoring. There is a pressing need for more efficient and cost-effective diagnostic technologies that can continuously provide rapid and accurate measurement, facilitating timely decision-making and better patient care. A major technical challenge in continuous biomolecular monitoring is achieving fast response while maintaining high specificity and sensitivity. Sensitive and selective molecular detection requires slow analyte-binder dissociation and long incubation to reach equilibrium. Rapid sensor response, on the other hand, calls for fast analyte dissociation and association that are difficult to achieve for low-abundance analytes. Most clinical assays are optimized for high sensitivity to low-abundance circulating biomarkers and are often single-use, making them prohibitively expensive for frequent biomolecular monitoring. To address this issue, we propose a mechanism called photothermal recycling (PTR), which mimics the thermal cycling process in PCR and uses the photothermal effect to rapidly recycle affinity reagents for frequent measurements. In this study, we investigated the thermal transport process during photothermal recycling at the biomolecule-nanomaterial interface and examined the impact of transient, localized heating on biomolecular interactions. Additionally, we developed an ultrasensitive digital assay format compatible with the PTR mechanism for continuous biomolecular monitoring. Our results show that the photothermal recycling process can effectively regenerate bio-nano surfaces for highly sensitive biomolecular detection over multiple hours in complex biofluids. Repeated photothermal cycling impacts the structure and function of various molecular scaffolds differently, affecting specific and non-specific interactions. Using DNA aptamers as a model molecular recognition system, we demonstrated the performance of our assay by measuring low-abundance immune mediators and hormones in serum. These biomarkers have previously been shown to be associated with poor outcomes in critically ill sepsis patients under intensive care. This study advances the understanding of nanoscale mass and energy transport at the biomolecule-nanomaterial interface. The technology platform developed here has the potential to significantly improve patient care and facilitate personalized medicine.

Presenting Author: Jing Pan University of Florida

Presenting Author Biography: Dr. Jing Pan is an assistant professor in Mechanical and Aerospace Engineering at the University of Florida. He received his Ph.D. in Mechanical Engineering from Purdue University. During his Ph.D., Dr. Jing Pan worked on engineering DNA-based synthetic motors and optical sensors. He conducted his postdoctoral research at Stanford University where he worked on designing switchable affinity reagents for biomedical sensing applications. He currently directs the Biodesign Laboratory at UF. His research focuses on engineering biomolecules and nanomaterials for emerging biosensing applications in life science research and healthcare.

Authors:

Yongchen Tai University of Florida
Yunshen Li University of Florida
Wenting Wang University of Florida
Mitchell Conover University of Florida
Jing Pan University of Florida