Regulating Biomolecular Surface Interactions Using Tunable Acoustic Streaming

Diffusion limitations and nonspecific surface absorption are great challenges for developing micro-/nanoscale affinity biosensors. There are very limited approaches that can solve these issues at the same time. Here, an acoustic streaming approach enabled by a gigahertz (GHz) resonator is presented to promote mass transfer of analytes through the jet mode and biofouling removal through the shear mode, which can be switched by tuning the deviation angle, a, between the resonator and the sensor. Simulations show that the jet mode (a = 0) drives the analytes in the fluid toward the sensing surface, overcomes the diffusion limitation, and enhances the binding; while the shear mode (0 < a < p/4) provides a scouring action to remove the biofouling from the sensor. Experimental studies were performed by integrating this GHz resonator with optoelectronic sensing systems, where a 34-fold enhancement for the initial binding rate was obtained. Featuring high efficiency, controllability, and versatility, we believe that this GHz acoustic streaming approach holds promise for many kinds of biosensing systems as well as lab-on-chip systems.

Automated summary

In this study, the authors propose an approach that utilizes a gigahertz (GHz) resonator to enable acoustic streaming for improving mass transfer and biofouling removal in micro-/nanoscale affinity biosensors. By tuning the deviation angle, a, the flow mode and shear mode can be switched, overcoming diffusion limitations and enhancing binding while removing biofouling. Experimental results show a 34-fold enhancement in initial binding rate, indicating the potential of this approach for biosensing and lab-on-chip systems.