Optical Biosensors Joel Kindt Lauren Netherton Acknowledgements Dr. Kevin Lear Dr. Dave Kisker Weina Wang Hailey Cutler 1

Lauren Netherton Motivation and Introduction Prior Research How Optical Biosensors Work 2

“60% of Golden Retrievers Die of Cancer” “1 in 4 Dogs Will Die of Cancer” -Morris Animal Foundation 3 Courtesy of Kian Behbakht of UC Denver

Prior Research Senior Design Team

Pipe Organ Analogy Place fruit in organ pipe Changes pitch based on: –Size –Shape 5

6 Optical Detection & RF Switch Circuit Spectrometer Healthy Cancerous! Courtesy of Weina Wang

Trapping Requirements Lower voltages –Trap at slower velocity Higher voltages –Trap at higher velocity 7

Dielectrophoretic Force Use of electromagnetics Non-uniform electric field –Polarizes molecules within cell –Induces DEP force to hold cell in trap Electric field 8 December 2007 Senior Design Presentation

Polarization factor (K factor): Complex permittivity of particle/suspending medium: Dielectrophoretic Force 9 Courtesy of Weina Wang

Joel Kindt Electrostatic Modeling Experimental Data Budget Conclusions and Future Work 10

Electrodes on Chip 11

Electrostatic Modeling 12

DEP ForceE-Field 13

Positive and Negative DEP Mammalian white blood cell σ m = 0.1 S/m (~ water) σ m = 1.5 S/m (~ PBS) Joel Voldman, “Electrical Forces For Microscale Cell Manipulation”, Annu. Rev. Biomed. Eng : Polarization factor (K factor):  K > 0: Positive DEP  K < 0: Negative DEP,

Experimental Setup 15

Impedance of Channel Voltage Divider 16

 more heat dissipated at lower impedance 17 Impedance of Channel

Budget Materials1 st semester budget 1 st semester actual 2 nd semester budget Syringes$15$0$15 Glass$75$0 Nanoports$0 $60 Nanotubing$0 $25 Flexible mirror$10$0 Total$100$0$100 18

Know trapping requirements for various fluid velocities Possible to model cell trap through simulations –Electric field –DEP force The fluid properties can affect results –K factor –Impedance of channel 19 Conclusions

Design better cell trap through simulations Further understand spectra –Cancerous vs. non-cancerous cells –Different types of cancer Save Rover! 20 Future Work