The spectral bio-diagnosis of normal human body saliva sample shows the following functional compounds and it is related to various proteins and enzymes. Because of the presence of water in the saliva sample, the hydroxyl group is observed in the form of O–H at 3,305 cm−1, because of the presence of lipids, the functional group C–H is obtained from 2,928 to 2,856 cm−1, due to the presence of amide-I in the form of C=N and C=C obtained at 1,658 cm−1, the proteins are exhibited. Due to the presence of aliphatic CH2, the Lipids, Adenine, Cytosine, Collagen are observed at 1,455 cm−1, because of the presence of Carbohydrates, Phospholipids, Nucleic acids, the functional groups C=O and P=O from 1,159 to 1,064 cm−1 are exhibited. Due to the presence of Phenylalanine, Tyrosine, Cystine and Hydroxyapatite C–C twist, C–C stretch, C–S stretch and PO42− are observed at 748 and 483 cm−1. Silver nanoparticle has attracted considerable interest due to their extensive applicability in various areas such as electronics, catalysis, chemistry, energy and medicine. To study the opto-electronics properties of the samples, it was mixed with silver nanoparticles and characterized. © 2014, The Author(s).