A label-free immunosensor for determination of salbutamol based on localized surface plasmon resonance biosensing.

We developed a localized surface plasmon resonance (LSPR)-based label-free optical biosensor for detection of salbutamol (Sal). Hollow gold nanoparticles (HGNs) which deposited on transparent indium tin oxide (ITO) film coated glass was used to sensing platform. Antibody against Sal was immobilized on HGN surface to recognize the target Sal molecules. Thus, the change of LSPR peak was proportional to the concentration of Sal in the solution. The experimental results demonstrated that the LSPR immunosensor possessed a good sensitivity and a high selectivity for Sal. The detection range for Sal was from 0.05 to 0.8 μg/mL with a correlation coefficient of 0.996. The biosensor was applied for the detection for Sal in spiked animal feed and pork liver samples, and the recoveries were in the range of 97-105 %. Therefore, it is expected that this approach may offer a new method in designing label-free LSPR immunosensor for detection of small molecules.