Figure 1.

Summary of the discovery workflow and microtoroid experimental setup. A, previous study by Galey et al. collected murine vaginal lavages for xenograft OVCAR-8-RFP mice over 8 weeks and profiled each lavage using MALDI-TOF mass spectrometry (MS). B, the current study seeks to identify proteins detected from MALDI-TOF MS protein profiles and use more sensitive detection techniques. C–F, schematic of cystatin A biosensing experimental setup using FLOWER. C, preparation of the microtoroid for binding to the cystatin A–Ab complex. D, block diagram of the FLOWER system. A digital laser locking module enables adaptive tracking of the microtoroid’s resonance frequency, which changes as analytes bind to its surface. E, schematic representation of the microfluidic chamber designed to allow the passage of the optical fiber. F, an isometric view showing analyte molecules (green) binding to the surface of the toroid. The toroid is shown positioned next to a tapered optical fiber for evanescent coupling of light into the toroid.