Ultra compact, high sensitivity label-free biosensor using VCSEL

We report a new label-free biosensor system for protein interaction characterization. The system consists of a VCSEL, a plastic guided mode resonant filter, and a pin detector. The sensor has high sensitivity and ultra compactness, consumes low power, and can be fabricated in 2D arrays.

One of the greatest challenges in molecular biology is to understand how the many protein targets encoded by DNA interact with other proteins, pharmaceutical candidates, and a large host of enzymes and inhibitors [1], [2]. The different sensing techniques can be put into 2 groups: labeling with fluorescent compounds and direct molecule identification. Label attachment increases assay complexity and possibly alters the functionality of molecules through conformational modification or epitope blocking. Hence, various label-free biosensor technologies have einerged. Among the optical techniques are surface plasmon resonance, ellipsometry and reflectance interference spectroscopy. These sensors, though exhibit high sensitivities, are bulky, slow and expensive.