Abstract
Despite the increasing demand for nanoscale biomolecule analysis for point-of-care (POC) application, nanoparticle separation remains a challenge in many applications due to huge sample loss during separation, low throughput, large scale input materials requirement, and sophisticated technologies. As the separation efficiency may affect the subsequent sample processing and analysis, a robust and reliable size-based separation technique is necessary. This study presents a lab on a chip system to enhance the separation performance by using rapid and straightforward polymer prototyping. In particular, the system consists of a microfluidic network with embedded membrane filters with different pore size cut-offs and an ultrasonic transmitter for acoustic agitation. Using the novel system, we successfully demonstrate the fractionation of 15 nm Au NP from polydisperse nanoparticle solution in the presence of ultrasonic wave (28-40 kHz) generated by the transducer incorporated with the microfluidic system during the separation. Ultrasonic irradiation helps in preventing cake formation and reversing the fouling process by acoustic agitation. The suggested system significantly increases the flow rate during the separation process and improves the recovery of target size nanoparticles. This microfluidic platform is expected to serve as a powerful tool for sample preparation and analytical methodology in POC applications.