Molecular fingerprinting of biological nanoparticles with a label-free optofluidic platform

Label-free detection of multiple analytes in a high-throughput fashion has been one of the long-sought goals in biosensing applications. Yet, for all-optical approaches, interfacing state-of-the-art label-free techniques with microfluidics tools that can process small volumes of sample with high throughput, and with surface chemistry that grants analyte specificity, poses a critical challenge to date. In a collaboration between ETH Zurich and Harvard MGH, we developed an optofluidic platform that brings together state-of-the-art digital holography, PDMS microfluidics, and surface chemistry to deliver high throughput single-particle detection with molecular specificity. Specifically, our platform fingerprints heterogeneous biological nanoparticle populations using a panel of biomarkers. As a proof of concept, we apply our technology to four different ovarian cell-derived extracellular vesicle samples and obtain unique fingerprints, enabling their robust classification.