Nanoparticle-based fiber optofluidic laser for label-free protein detection

摘要

Fiber optofluidic laser (FOFL) is a promising technology for investigating biomedical and chemical interactions. However, label-free FOFL for small molecular weight protein analysis remains a major challenge. Here, a nanoparticle-based fiber optofluidic laser is demonstrated to achieve label-free biodetection of small molecular weight protein. The proposed FOFLs amplify the loss inside the optical fiber microring through the nanoparticle enhanced light-matter interaction, enabling the detection of small molecular weight protein. The laser dye and the nanoparticle-based immunoassay kits are homogeneously mixed to achieve the label-free biodetection. The C-reactive protein (CRP) is detected in the dynamic range of 38.1 ng/mL to 381 ng/ml with a limit of detection of 26 ng/ml, which is two orders of magnitude lower than that of methods without nanoparticles. The assay time can be as short as 15 min with a low-volume biosample/reagents consumption of 301 nL. This novel concept not only provides a simple but versatile method to achieve the label-free biodetection of small molecular weight protein, but also deepens insight into how molecules interact with the laser emission.