Using an effective tight-binding model, together with a transfer matrix technique, we investigate the electronic transport through oligopeptide chains, such as amino acid pairs and the Alpha3-helical polypeptide and its variants, sandwiched between two platinum electrodes. Our results show that factors such as the oligopeptide chain length and the possible combinations between the amino acids residues are crucial to the electronic conductance profiles. The temperature dependence of the electronic specific heat at constant volume spectra are also depicted. Applying our findings to single-stranded microRNAs (miRNAs) chains, which are associated to autism disorder, a relationship between the current intensity and the autism-related miRNA bases sequences is detected, suggesting that a kind of electronic biosensor can be developed to distinguish different profiles of autism spectrum disorders.