^{Connducting polymers are known for their application in medical field. The most popolar of the conducting polymers include Polyaniline(PANI), Poly(1-naphthylamine) (PNA), Polypyrrole(PPy) etc. Polyaniline being one of the best known polymers that show applications of medicinal value. Polyaniline has shown it's efficacy in being used in biosensors and for drug delivery. Polyaniline can be doped by various biocompatible materials such that it's biocompatibility and hence it's use can be enhanced in biosensors and in drug delivery. We have synthesized polyaniline doped with cysteine. Different molar ratios of aniline:cysteine moieties were mixed for the process, followed by ultrasound assisted polymerization. The synthesized system is characterized using IR, UV and SEM. Its protein sensing capability has been determined using various techniques like molecular docking, cd spectral analysis and fluorescence. The overall studies reveal that with the increase in cysteine content in the polymer:cysteine ratio, the quenching constant was reported to be increasing, owing to the fact that the increased amount of cysteine tends to increase the solvation of the synthesized PANI:Cys systems. The PANI:Cys oligomers with the molar ratios of 50:50 and 80:20 was reportedly showing higher binding energy as compared to the oligomer with 20:80 ratio of PANI:Cys. The overall studies indicate clearly that the oligomers synthesized can be used in protein sensing.}