Hydrogel integrated optofluidic microlasers for biomedical applications

Abstract

Optofluidic microlasers have demonstrated several unique properties which include narrow linewidth, sharp spectrum, high intensity and distinct threshold, leading to orders of magnitude increase in the detection sensitivity. Herein, we incorporated hydrogel droplets inside a microcavity of the surrounding aqueous environment and investigated its capability in sensing and detection. Hydrogels are highly responsive to external stimuli causing subtle physical changes which can be detected via lasing emission signals that will be amplified due to the confined light-matter interaction within the microcavity. The results show that the hydrogel integrated optofluidic microlaser is sensitive to the change in optical path length upon induced osmotic pressure. Furthermore, exosomes specifically captured via antibodies can also cause observable changes in the lasing emission output. By analysing the spectral lasing shift and spatial laser modes, this research shows that this novel method has the potential for on-chip sensing of body fluids and the detection of exosomes.