Experiments involving saliva from human volunteers were conducted
in accordance with and upon approval of the Institutional Review Board at the University of Texas at San Antonio. All subjects
received informed consent forms before inclusion in the study and
voluntarily agreed to participate. Samples of saliva were collected
from six subjects 2.5 h after consumption of food. The samples were
filtered using a 0.2 m PTFE filter (VWR; Radnor, PA) and analyzed
for nitrite using the PAD. Table 1 summarizes the results from six
subjects using the PAD as a platform for nitrite detection.