Localized Surface Plasmon Resonance-Based Micro-Capillary Biosensor

A highly sensitive localized surface plasmon resonance (LSPR)-based micro-capillary biosensor for micro-measurement was described in this letter. The sensing strategy relies on the interrogation of changes in transmission intensity due to the evanescent field absorption of gold nanoparticles immobilized on the inner wall of micro-capillary. The absorbance due to the LSPR was found to be linear to refractive index changes between 1.328 and 1.3617, and the sensitivity was calculated to be 937% RIU-1. Then, to evaluate the biosensing performance of the LSPR sensor, we demonstrated the capture of transferrin protein by a layer of anti-transferrin solution immobilized on the LSPR sensor at different concentrations. Experimental results suggest that the biosensor we reported presents a good performance in real-time biochemical detection. In addition, with the advantages of low cost, simplicity, high sensitivity, and less amount of samples required, the biosensor we reported can be used for rapid micro measurement in chemical, biological, and medical applications.