Rapid and sensitive detection of chemical and biological analytes
becomes increasingly important in areas such as medical diagnostics,
food control and environmental monitoring. Optical biosensors based on
surface plasmon resonance (SPR) and optical waveguide spectroscopy have
been extensively pushed forward in these fields. In this book, we
combine long range surface plasmons (LRSPs), surface plasmon-enhanced
fluorescence spectroscopy (SPFS) and optical waveguide spectroscopy with
hydrogel thin film for highly sensitive detection of molecular analytes.
LRSPs are special surface plasmon waves propagating along thin metal
films with orders of magnitude higher electromagnetic field intensity
and lower damping than conventional SPs. Therefore, their excitation on
the sensor surface provides higher fluorescence signal for molecules
detection. The hydrogel thin film attached on a sensor surface served
both as a binding matrix and as an optical waveguide for probing
molecules interactions. The higher binding capacity of hydrogel and low
damping of optical waveguide provide higher sensitivity for molecules
detection as compared to regular SPR.