TY - GEN
T1 - Nanowire-GMR integrated microfluidic biosensor
AU - Bellamkonda, Ramya
AU - John, Tom
AU - Mathew, Bobby
AU - Hegab, Hisham
AU - DeCoster, Mark
AU - Davis, Despina
PY - 2009
Y1 - 2009
N2 - Nanowires based GMR is ideal to be integrated in microfluidic devices due to its efficient detection of sensitive magnetic fields. Nanowire based GMR microfluidic sensor is used to detect different fluids based on their magnetic behavior. This paper demonstrates the fabrication and testing of nanowire based GMR biosensors with four different control solutions: 1) DI-water, 2) Phosphate Buffered Saline (PBS), 3) polystyrene superparamagnetic beads, and 4) commercially available magnetic Dynabeads. The device is fabricated in PDMS by using a lithographically patterned silicon wafer as the mold. The nanowire based GMR material, 3 mm by 3 mm in size, is inserted inside the PDMS close to the channel during the fabrication. The channel in the PDMS substrate is sealed by bonding it to a glass plate using Reactive-Ion-Exchanger (RIE). GMR device is tested potentiostatically using a computer controlled function generator (Solatron, SI 1287). A highest resistance of 0.748 ω is recorded for the sensor, in the absence of magnetic field. A resistance change of 0.6% is obtained in the presence of a magnetic field (B=0.035T) between water and polystyrene superparamagnetic beads when pumped through the microchannel. The sensor showed a resistance difference of 0.31% between IX diluted PBS and 100X diluted dynabeads, in the presence of a constant magnetic field of 0.035T. This characterization would be useful in the development of a BioMEMS sensor using nanowire based GMR.
AB - Nanowires based GMR is ideal to be integrated in microfluidic devices due to its efficient detection of sensitive magnetic fields. Nanowire based GMR microfluidic sensor is used to detect different fluids based on their magnetic behavior. This paper demonstrates the fabrication and testing of nanowire based GMR biosensors with four different control solutions: 1) DI-water, 2) Phosphate Buffered Saline (PBS), 3) polystyrene superparamagnetic beads, and 4) commercially available magnetic Dynabeads. The device is fabricated in PDMS by using a lithographically patterned silicon wafer as the mold. The nanowire based GMR material, 3 mm by 3 mm in size, is inserted inside the PDMS close to the channel during the fabrication. The channel in the PDMS substrate is sealed by bonding it to a glass plate using Reactive-Ion-Exchanger (RIE). GMR device is tested potentiostatically using a computer controlled function generator (Solatron, SI 1287). A highest resistance of 0.748 ω is recorded for the sensor, in the absence of magnetic field. A resistance change of 0.6% is obtained in the presence of a magnetic field (B=0.035T) between water and polystyrene superparamagnetic beads when pumped through the microchannel. The sensor showed a resistance difference of 0.31% between IX diluted PBS and 100X diluted dynabeads, in the presence of a constant magnetic field of 0.035T. This characterization would be useful in the development of a BioMEMS sensor using nanowire based GMR.
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U2 - 10.1115/FEDSM2009-78529
DO - 10.1115/FEDSM2009-78529
M3 - Conference contribution
AN - SCOPUS:77953866489
SN - 9780791843734
T3 - Proceedings of the ASME Fluids Engineering Division Summer Conference 2009, FEDSM2009
SP - 535
EP - 538
BT - Proceedings of the ASME Fluids Engineering Division Summer Conference 2009, FEDSM2009
T2 - 2009 ASME Fluids Engineering Division Summer Conference, FEDSM2009
Y2 - 2 August 2009 through 6 August 2009
ER -