  Droplet microfluidics offers a versatile platform for analyzing liquid
samples. Despite its potential, there is a lack of techniques that allow to
reliably probe individual circulating droplets. The prospect of combining
droplet microfluidics with sensitive, broadband spectroscopic techniques would
therefore unlock new capabilities for various disciplines, including
biomedicine and biochemistry. Here we present an integrated optofluidic
platform that seamlessly combines droplet microfluidics and advanced
hyperspectral imaging. This enables high-resolution, label-free analysis of
single picolitre-sized droplets, providing valuable insights into their
content. As a proof-of-principle, we demonstrate the ability of our platform to
study rapid dynamic changes in a heterogeneous population of plasmonic
nanoparticles with millisecond-time resolution. Furthermore, we demonstrate the
effectiveness of the platform in biosensing applied to short DNA strands,
achieving a detection sensitivity in the range of 100 pM. Finally, we show that
the platform provides the flexibility to monitor samples over extended periods
of time (hours) in a multiplexed manner.
