Au-nanoshells modified surface field enhanced LRSPR biosensor with low LOD for highly sensitive hIgG sensing

A high sensitivity side polished fiber long-range surface plasmon resonance (LRSPR) biosensor with electronic field enhanced through surface modified with Au-nanoshells is proposed to detect human immunoglobulin G (hIgG). LRSPR which has high penetration depth and long propagation distance can effectively detect bio-macromolecules. The plasmon coupling effect between the Au-nanoshells and Au-film can enhance the electric field intensity on the surface of the sensor, which makes the proposed sensor structure have a lower limit of detection (LOD) and higher sensitivity. The experimental results show that the sensitivity as well as LOD of side polished-fiber (SPF)/dielectric-matching-layer (DML)/Au-film/Au-nanoshells sensor is 1.84 nm/(mu g/mL) and 0.20 mu g/mL, which indicates better responses to hIgG with a concentration range of 1-40 mu g/ml compared with the SPF/DML/Au-film sensor. The LRSPR sensor modified by Au-nanoshells was used to detect chicken serum samples and the calculated recovery is 107.62%, showing good practicality and superior self-referenced function. The biosensor has the advantages of small volume, high sensitivity and long-distance detection, and has good practicability in the field of biochemical sensing.

Automated summary

The study presents a high sensitivity side polished fiber LRSPR biosensor with surface modified Au-nanoshells for detecting hIgG. Experimental results show that the sensor has higher sensitivity, lower limit of detection, and good practicality when detecting chicken serum samples. The biosensor offers advantages of small volume, high sensitivity, and long-distance detection in the field of biochemical sensing.