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

TL;DR

This paper presents a novel optofluidic platform combining digital holography and microfluidics for label-free, high-throughput fingerprinting of biological nanoparticles with single particle sensitivity, useful for biomarker profiling.

Contribution

The authors develop a new integrated platform that combines digital holography with microfluidics and supported lipid bilayers for multiplexed, label-free nanoparticle analysis.

Findings

Successfully profiles extracellular vesicle populations from ovarian cells.

Demonstrates single particle sensitivity and robustness of the platform.

Develops unique biomarker fingerprints for different cell lines.

Abstract

Label-free detecting 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. Here, we introduce an optofluidic platform that brings together state-of-the-art digital holography with PDMS microfluidics by using supported lipid bilayers as a surface chemistry building block to integrate both technologies. Specifically, this platform fingerprints heterogeneous biological nanoparticle populations via a multiplexed label-free immunoaffinity assay with single particle sensitivity. Herein, we first thoroughly characterise the robustness and performance of the platform, and then apply it to profile four distinct ovarian cell-derived extracellular vesicle populations over a panel of surface protein biomarkers, thus developing a unique biomarker fingerprint for each cell line. We foresee that our approach will find many applications where routine and multiplexed characterisation of biological nanoparticles is required.