Optical nanotechnology enables rapid label-free diagnostics for cancer biomarker screening

摘要

A high-accuracy biosensor system has been developed to provide rapid detection of biomarker proteins as indicators of ovarian cancer. This photonic detection system is based upon guided-mode resonance sensor technology. The buildup of the attaching biolayer can be monitored directly, without use of chemical tags, by following the corresponding resonance shift with a spectrometer or detector array. Additionally, these high-resolution sensors employ multiple resonance peaks at identical physical location on the sensor surface. Each of these resonance peaks responds uniquely to the detection event, thereby enriching the data set available for quantification. The peaks result from individual, polarization-dependent resonant leaky modes that are the foundation of this technology. Examples are presented for detection of ovarian cancer biomarkers (fibronectin and apoliprotein A-1) in serum and cell culture supernatant, with detection sensitivities to ~20 ng/ml. Minimal nonspecific binding was measured in cell media and serum backgrounds. We also present an example dual-polarization resonance response with corresponding backfitting results that illustrate the capability to distinguish between changes at the sensor surface due to biolayer adhesion and those due to sample background changes.