Question $1(40$ points$)$

Design an evanescent immunosensor for the detection of severe acute respiratory syndrome coronavirus $2($SARS$-$CoV$-2$; the causative agent of COVID$-19).$

$($A$)$ Draw a schematic to illustrate an assay design based on attenuated total reflectance $($ATR$),$ please include the following items:

Capture antibody, primary detection antibody, and secondary detection antibody $($remember to specify the names of the antibodies as well as label$($s$)$ for detection if any$)$;

Final configurations of the negative $($absence of SARS$-$CoV$-2)$ and positive $($presence of SARS$-$CoV$-2)$ samples;

Optical detection parameter$($s$),$ i$.$e$.,$ wavelength$($s$)$;

Plots of signal against time for different concentrations of SARS$-$CoV$-2.(25$ points$)$

$($B$)$ Draw a schematic to illustrate an assay design based on total internal reflection fluorescence $($TIRF$),$ please include the following items:

Capture antibody, primary detection antibody, and secondary detection antibody $($remember to specify the names of the antibodies as well as label$($s$)$ for detection if any$)$;

Final configurations of the negative $($absence of SARS$-$CoV$-2)$ and positive $($presence of SARS$-$CoV$-2)$ samples;

Optical detection parameter$($s$),$ i$.$e$.,$ wavelength$($s$)$;

Plots of signal against time for different concentrations of SARS$-$CoV$-2.(15$ points$)$