Detection of CD4 and CD8 t-lymphocytes and HER2 breast cancer biomarker using the opto-fluidic ring resonator biosensor

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] We have demonstrated label-free detection of CD4+ and CD8+ T-Lymphocytes and HER2 breast cancer biomarker using the opto-fluidic ring resonator (OFRR) sensor. The OFRR sensing platform incorporates microfluidics and photonics in a setup that utilizes small sample volume and achieves a fast detection time. For T-Lymphocyte cell detection, white blood cells were isolated from healthy blood and the concentrations adjusted to match T-Lymphocyte levels of individuals infected with HIV. Detection was accomplished by immobilizing CD4 and CD8 antibodies on the inner capillary surface of the OFRR. Sensing results show excellent capture of CD4+ and CD8+ T-Lymphocytes at medically significant concentrations with a detection time of approximately 30 minutes. Protein biomarkers have recently been heavily researched in their roles in the detection, quantification, and monitoring of aggressive types of breast cancer. We describe a novel, label-free approach for detecting the HER2 extra-cellular domain breast cancer biomarker in human serum samples using the opto-fluidic ring resonator (OFRR). HER2 proteins were spiked in serum at varying concentrations. Results show that the OFRR is able to detect HER2 at medically relevant concentrations in serum ranging from 13 ng/mL to 100 ng/mL in 30 minutes. Our work will lead to a device that can be used as a tool for monitoring disease progression in a low cost sensing setup.