Viscoelastic flow-integrated Raman spectroscopy platform

Abstract

We demonstrate the first viscoelastic-based flow-integrated Raman spectroscopy (FIRS) platform using spontaneous Raman spectroscopy with a simplified fluidic design that precisely controls particle transit speed and predicts arrival time to the Raman interrogation region, together with time synchronized triggered acquisition. Using viscoelastic flow focusing and optical detection of velocity for hardware triggering, the setup enables high-throughput, real-time Raman analysis of particles in continuous flow. The system operates with a single pressure pump, two sets of fiber-coupled lasers and detectors, and a microcapillary precisely aligned in a projection micro-stereolithography 3D-printed mount, and ensures detection stability across various flow rates. The demonstrated platform is modular and scalable. Detection rates of up to 80 cells per minute were achieved and dinoflagellate Alexandrium ostenfeldii cultures were analyzed. The integrated optical trigger mechanism supports future extensions such as cell sorting or additional analyses. A user-friendly graphical interface provides full control of fluidics, spectroscopy, and real-time monitoring, making this compact, low-cost FIRS platform accessible across a wide range of laboratory environments.