3.3.2. Effect of the concentration of AgNPls
The effect of AgNPls concentrationwas investigated in the range
of 40–360mgmL1. As the results show in Fig. 3b, DI increased
with increasing AgNPls concentration and tends to be stable above
200mgmL1. Therefore, 0.8mL of 200mgmL1 AgNPls was used to
prepare the detection and control zone on the paper-based sensor
in future experiments.