Poly(methyl metacrylate) conductive fiber optic transducers as dual biosensor platforms

Herein the development of an alternative optic-conductive fiber configuration applied for the construction of biosensing platforms. This new approach is based on applying the chemical polymerization of pyrrole onto the surface of polymethyl metacrylate (PMMA) fibers to create a polymer—a conductive surface, onto which an additional photoactive polypyrrole-benzophenone (PpyBz) film is electrochemically generated upon the fiber surface. Irradiation of the benzophenone groups embedded in the Ppy films with UV radiation (350 nm) formed active radicals that allowed the covalent attachment of the desired bioreceptors. Characterization of the amperometric biosensing matrix was accomplished by using a model Urease (Urs) through electrochemical impedance spectroscopy (EIS) and amperometry. Both techniques have shown a low charge transfer resistance (340 kΩ) and a high sensitivity (12.3 μA mM⁻¹ cm⁻²). Thereafter, the construction of an optical biosensing matrix based on horseradish peroxidase (HRP) production of photons was carried out. The high signal to noise (S/N) ratio (1600) indicated clearly that this approach can serve as a new platform to replace glass optical fibers based on biosensors.