Proteins extracted from saliva immunoglobulin G (IgG) and bovine serum albumin (BSA) were labeled with fluorescent dyes, and the labeling procedure for Alexa Fluor 488 (AF488) NHS ester was described below. The previously treated solid-phase-bound lectin was washed with TBS buffer (pH 7.4). For comparison, two labeling workflows were applied: (A) lectin binding to proteins followed by fluorescence labeling, termed lectin-first fluorescent labeling (LF); (B) fluorescent labeling of proteins followed by lectin affinity of fluorescently labeled proteins, termed fluorescent-first lectin binding (FF). For the LF workflow, the extracted salivary proteins were incubated with AAL, LCA, and UEA-I immobilized beads and a mixture of three lectins (200 μg lectins, respectively) in 0.5 ml of TBS buffer. Samples and lectins were incubated overnight at 4 °C. Then centrifuge at 3000 × g for 1 minute and remove the supernatant. After five washes with 0.5 ml of DI water, fluorescence binding buffer (0.2 M sodium carbonate, 1 M sodium chloride) and excess AF488 NHS ester were added for labeling (Fig. S1†). The fluorescent tags were reacted at room temperature for 16 h, then the excess fluorescent tags were washed with TBS buffer, and 200 μL of fluorescently labeled beads were transferred to a 96-well plate for fluorescence detection. For the FF workflow, 200 μg of lyophilized salivary protein was first dissolved in fluorescence binding buffer to a final concentration of 10 μg μL−1. An excess of AF488 was added and allowed to react for 16 h at room temperature. The reaction was quenched with an equal volume of 2 M Tris–HCl (pH 7.5) to inactivate the NHS group, and purified from unreacted AF488 dye by ultrafiltration centrifuge dialysis. TBS buffer were added to make up the volume to 300 μL, and centrifuge twice for 20 min at 140 00 × g. Fluorescently labeled samples were reacted with lectin overnight at 4 °C. Samples were transferred to a 96-well plate and the fluorescence was measured by reading excitation/emission (EX/EM) wavelengths at 495/519 nm using a multifunctional microplate reader (Tecan Infinite M1000 Pro; Tecan Group Ltd; Mannedorf, Switzerland). All measurements were background subtracted using blank beads.