Graduation Year


Document Type




Degree Name

MS in Engineering Science (M.S.E.S.)

Degree Granting Department

Mechanical Engineering

Major Professor

Manoj Ram, Ph.D.

Co-Major Professor

Ashok Kumar, Ph.D.

Committee Member

Ajit Mujumdar, Ph.D.


Deposition, Lactic acid, Polypyrrole, Immobilization, Current Density, Chronoamperometry, Properties, Oxidase


Lactic acid is widely existing in human bodies, animals and microorganisms. Recently, using biosensor to detect the concentration of lactic acid and diagnose disease have attracted great research and development interests. Nanocomposites is one of the best material used for biosensor because their wonderful conductivity, optical and electrochemical properties. In the study, MoS2 and polypyrrole (PPY) are used for the composite material electrode. To determine whether lactate oxidase (LOD) was helpful for the biosensor’s detective properties, both PPY-MoS2 film with LOD and PPY-MoS2 film without LOD are being tested. The fourier transform infrared spectroscopy (FTIR) and Raman spectroscopic techniques have been used to understand the chemical bonds in the nanocomposite film. The X-ray diffraction (XRD) technique has been performed to understand the crystallographic structure of the MoS2 -PPY film. The morphologies were confirmed by scanning electron microscopy (SEM). The UV-vis spectroscopy has been used to determine the band structure of composite film. Cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) were used to analyze in different concentration of solution, under different scan rate to obtain stability and work efficiency. These results were compared with PPY-MoS2 film with and without lactate oxidase conditions. The chronoamperometric technique has been used to detect the concentration of lactic acid.