@genmaicha yes! at least those with "Ag" in the name should contain some gold.
> At a "conjugate pad," antibodies with gold nanoparticles attach to any SARS-CoV-2 antigens present in the sample.[38] At the test line (which may be labelled "T"), antibodies specific to SARS-CoV-2 are present.[38] At the control line (which may be labelled "C"), antibodies that can attach to the antibodies with nanoparticles are present.[38] If only the control line is visible, the test is negative; if both the control and test lines are visible, the test is positive.[38][39][40]
https://en.wikipedia.org/wiki/COVID-19_rapid_antigen_test#Methods