Portable Optofluidic Device for Dynamic Binding Analysis in Field-Settings

Abstract

Compact and portable biosensing technologies play an important role in replacing traditional counterparts that require costly and heavy equipment, as well as complex infrastructure. The integration of these easy-to-use and cheap devices allows for the conducting of biosensing analyses in resource-limited settings. The study produced a portable optofluidic platform that is lightweight (260 g) and compact (16 cm×10 cm×11 cm). It combines subwavelength nanohole arrays, microfluidics technology, and on-chip computational imaging. It records plasmonic diffraction field images with a CMOS imager and an LED light, allowing for a large field of view for refractive index measurement. This LED source generates diffraction patterns on the imager. The microfluidic pump confirms accurate analyte delivery, allowing real-time analysis of diffraction field images to reveal time-dependent binding kinetics of biomolecules. It identifies biomolecular interactions without labelling, allowing for the detection and quantification of biomolecules. Our platform has an outstanding limit-of-detection (LOD) of 5ng/mL for label-free detection of protein IgG. We effectively determined the association and dissociation constants for protein A/G and IgG binding using real-time diffraction field images. The optofluidic biosensor platform is ideal for surface plasmon resonance (SPR) in field applications. It can monitor interactions in real-time, making it useful for studying the way various biological and chemical compounds bind in many areas. © 2024 SPIE.