For the modification step, the GSH-Cys-AgNPls solution was prepared via self-assembly of the
aminothiol on the AgNPls surface. Briefly, 1000 μL of 50 μM GSH and 5000 μL of 50 μM
Cys were added into 44 mL of 0.1 mM AgNPls solution and stirred for about 2 h to ensure a
complete self-assembly of the GSH and Cys onto the surface of AgNPls.