Different concentrations of MPXV neutralizing antibodies ranged from 0 ng/μL (PBS buffer), 1.56 ng/μL, 3.125 ng/μL, 6.25 ng/μL to 12.5 ng/μL were sequentially injected onto the MPXV protein functionalized surface. Each antibodies sample was incubated for 45 min within the detection chamber to facilitate MPXV protein-antibody binding interactions. After subtracting the PBS baseline, the normalized sensor responses were plotted in Fig. A1 (Appendix). The results demonstrate a linear relationship between the sensor signals and MPXV neutralizing antibodies concentrations. Slope of the sensor response curve also provides the detection sensitivity of the biosensor. It is determined to be 8.45 ng/μL /Hue unit.