Authors: H. Tanbakuchi, M. Bynum, R. Brennen, M. Whitener
Affilation: Agilent Technologies, United States
Pages: 629 - 631
Keywords: sensor, microwave, microfluidic, non-invasive, HPLC, SPR
SPR ( surface Plasmon Resonance) is an non destructive sensor capable of measuring the changes in refractive index above the gold surface (~300 nm) .The advantage of the SPR is in its capability of looking at measuring an array of reaction/binding and kinetics of the said process without a need for chemical tag. A high-sensitivity UV/VIS and diode array detectors and autosamplers with automation capability are the building blocks for the state of art HPLC systems that delivers the best performance, ease of use due to a solid and reliable sensor design. We are proposing to replace SPR sensor or use in conjunction with UV/VIs a sensitive Microwave stimulus that is capable of measuring variable reaction depth and can measure an array of Chem /Bio site.This new sensor is an outcome of a recent breakthrough of a unique measurement technique capable of measuring capacitance in sub Femto Farad and minute changes of the said capacitance. The change in the capacitance can be equated to change in dielectric constant of the medium. It is also known that the change in index of refraction and/or the concentration of chemical/biological medium corresponds to change in medium’s dielectric constant, therefore the change in capacitance per unit volume. The said changes of the dielectric constant with a properly designed sensor and measurement system can be translated to capacitance and changes in that capacitance . Therefore one can build an index of refraction/concentration/binding measurement system which has much higher sensitivity and spatial resolution of optical based system. Also it does not suffer from the measurement depth limitation that SPR suffers. In contrast the measurement volume can be set by the sensor design in advance.