To validate the application of this method in the real sample, three clinical human saliva samples (made available by the first affiliated hospital of Fujian Medical University, China) were tested. The clinical human saliva samples were diluted with Milli-Q reagent water in a 1:10 ratio before testing. Different PGDF-BB standard solutions were spiked into the human saliva samples; the results are shown in Table 1. The recoveries of the PGDF-BB were in the range of 96.5–102%. These results illustrated that the proposed sensor could be applied effectively to distinguish PGDF-BB in complex biological samples with a satisfactory accuracy.