A Solid-State Electrochemiluminescence Ethanol Biosensor Based on Electrogenerated Poly(pyrrole-tris(2,2-bipyridyl)ruthenium(II)) Film/Alcohol Dehydrogenase/Laponite Composite

Based on the solid-state electrochemiluminescence (ECL) of an electrogenerated polypyrrole tagged with tris(2,2-bipyridyl)ruthenium(II) complex ( denoted as polypyr-Ru), a new ethanol biosensor was fabricated by casting the composite of alcohol dehydrogenase (ADH) and laponite colloids onto the polypyr-Ru /Pt electrode. The two layer structure keeps the good robustness of the biosensor due to the electrostatic interaction between the negatively charged biocomposite coating and the positively charged polypyr-Ru. The morphology of the laponite-ADH composite coating is characterized by scanning electron microscopy. The electrochemical and ECL properties of the modified electrodes are investigated by cyclic voltammetry. The parameters concerning the ECL biosensor such as the amount of enzyme usage, the appropriate pH are optimized. The resulted ECL biosensor shows a good performance to detect ethanol.