A multi-functional plasmonic biosensor.
We present a coupler-free, multi-mode refractive index sensor based on nanostructured split ring resonators (SRRs). The fabricated SRR structures exhibit multiple reflectance peaks, whose spectral positions are sensitive to local dielectric environment and can be quantitatively described by our standing-wave plasmonic resonance model, providing a design rule for this multi-mode refractive-index (MMRI) sensor. We further manifest that the lower-order modes possess greater sensitivity associated with stronger localized electromagnetic field leading to shorter detection lengths within five hundreds nanometers, while the higher-order modes present mediate sensitivity with micron-scale detection lengths to allow intracellular bio-events detection. These unique merits enable the SRR-based sensor a multi-functional biosensor and a potential label-free imaging device.
Chang
Yun-Tzu
YT
Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
Lai
Yueh-Chun
YC
Li
Chung-Tien
CT
Chen
Cheng-Kuang
CK
Yen
Ta-Jen
TJ
D015374:Biosensing Techniques / Q000295:instrumentation*; D003198:Computer Simulation; D013057:Spectrum Analysis