Research On The Role Enhancing SPR Sensor's Sensitivity By Gold Nanorods

Surface plasmon resonance method has been widely used in variety of sensing applications, since it provides lable-free,non-destructive inspection,high sensitivity and array-based real-time sensing capability of detecting biochemical reactions on surface. However, in medical or food safety testing, the researchers often need to detect small molecules, which require surface plasmon resonance biosensors with higher sensitivity.Because of its surface enrichment effect and localization surface plasma resonance effect, metal nanoprticle could enhance the sensitivity of surface plasmon resonance biosensor. Now Au nanosphere gets the most research attention, by utilizing the surface enrichment effect and resonance effect of electromagnetic coupling with precious metals, it can enlarge the signal of SPR sensor more than twenty times. Among nanoprticles, there are great difference between Au nanosphere and Gold nanorod. Compare with Au nanosphere, Gold nanorod have a longitudinal plasma resonance absorption peak which has great sensitivity with the RI changes of surrounding. Because of these, Gold nanorod has great research worth in SPR biosensor. The gold nanorods with different aspect ratio which proposed by this paper was fabricated by typical seed-mediated solution phase approach. We creatively use the gold nanorods for surface plasmon resonance biosensor. The results showed that, using the gold nanorods conjugated with antibody as the second antibody could significantly amplify the response signal of the first antibody and antigen measured by double antibody sandwich method. And the gold nanorods whose longitudinal plasmon resonance absorption peak close to the surface plasmon wavelength, could promoto the SPR sensor get more sensitivity enhancement. The fabrication method of the gold nanorods is simple and low-cost.The structures and the unique optical properties of the membrane were studied by scanning electron microscope and spectrometer in this paper. The results showed that: with the increasment in aspect ratio of gold nanorods, the transverse plasmon resonance absorption peak almost unchanged, but the longitudinal plasmon resonance absorption peak gradually red shift. This research results obtained by previous match.