Regenerable Plasmonic Biosensor Based on Gold Nanolines Pattern and Common Laboratory Spectrophotometer

Gold nanostructures can undergo plasmonic behavior without need of light couplers like in traditional surface plasmon resonance (SPR) systems. This effect, known as LSPR (localized SPR), can be exploited to develop optical biosensors in simple configuration. In this paper, an LSPR system based on gold lines nanopattern as transducer has been developed by using a common laboratory spectrophotometer as reader and an adapted flow cell. This novel system was applied to anti-immunoglobulin G (IgG) detection, as proof of concept. For this purpose, the transducer surface was covalently biofunctionalized with IgG and incubated with increasing concentrations of anti-IgG. The response was determined by measuring changes in light transmission spectra (Δλ, in nanometers). Contrary to other reported nanopatterns, biosensor features as repeatability, regeneration, and detectability have been deeply studied. Results indicate that the system can act as a robust and regenerable biosensor with a limit of detection of 5.98 ± 1.34 nM.