High-throughput detection of human salivary cortisol using a multiple optical probe based scanning system with micro-optics and nanograting coupled label-free microarray

We demonstrate the use of a parallel detection system with a nanograting-based microarray to accomplish high-throughput analysis of bio-molecular interactions in a label-free manner. Well-type label-free microarrays were fabricated to eliminate the risk of cross-contamination and to minimize sample volumes. Parallel analysis without the use of spectrometer arrays or a moving platform was accomplished by using scanning multiple optical probes generated by a spatial light modulator and microlens array. Additionally, multiple optical probe spots focused by the microlens array reduced detection errors while enhancing the signal-to-noise ratio within a high-density microarray. Finally, we verified the feasibility of the parallel detection system by analyzing the peak wavelength value (PWV) shift of human salivary cortisol and anti-cortisol in a competitive binding experiment.