Angular interrogation

The MCLW sensor has been exploited by several groups for a wide range of experiments. However, both the design of the sensor and the detection scheme used in connection with the monitoring vary. This section reports on experiments using angular interrogation, absorbance detection and fluorescence detection. 

Fig. 13 Experimental waveguide sensor setup using a rotation stage for angular interrogation [28]...

Fig. 5 An actual resonant band image of 5 rows of 7 sensors in a 96-well sensor microplate containing living cells obtained using the arrayed angular interrogation system. The broken circle indicated that the cell density was not even across this specific sensor, which was confirmed by light microscope imaging (Reproduced with permission from ref. [18])...

ChG-based SPR detection has recently been evaluated [94-97]. The SPR peak position is extremely sensitive to refractive index variation in the sensing medium caused by presence of molecules, and the technique works by monitoring the SPR dip shift using Kretschmann angular interrogation geometry. A refractive index detection limit of 3 x 10 refractive index units (RIUs) was experimentally demonstrated in the ChG-based SPR sensing system [95]. 

Amplitude-based SPR sensing devices typically attain a refractive index resolution in the 10 —10 range. Angular and spectral interrogation-based systems provide even better resolution, allowing the measurement of refractive index changes as small as 10 . This corresponds to a detection limit for an adsorbed protein layer of less than 1 pg mm . ... 

For light atoms and certain linear radicals, s and 1 combine via the Russell-Saunders Coupling scheme to give a total angular momentum, j. EPR spectroscopy then interrogates transitions between the different j levels. Hence, since the Hamiltonian operator for an electron spin in a molecule contains a term representing the effect of... 

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