A multipurpose conjugated polymer: Electrochromic device and biosensor construction for glucose detection

First example of electrochemically polymerized thiazolothiazole containing electrochromic conducting polymer; Poly(2,5-di(furan-2-yl)thiazolo[5,4-d]thiazole) (PTTzFr) was obtained via cyclic voltammetry. The polymer structure bears furan unit as the donor and thiazolothiazole unit as the acceptor. PTTzFr film was obtained on an ITO coated glass slide and its electrochemical and optoelectronic properties were investigated. Polymeric film showed reversible redox behavior along with reversible electrochromic behavior from reddish orange to grey having a band gap value of 1.80 eV. It has fast switching times (0.3 s and 0.4 s) with high optical contrast values at visible and NIR regions (38% at 460 nm and 63% at 1225 nm). Optoelectronic device application was performed by constructing a dual type electrochromic device (ECD) with poly(3,4-ethylenedioxythiophene) (PEDOT). Resulting device showed a remarkable optical memory without changing its % transmittance value during 200 s at 450 nm. Additionally, to construct a sensing interface, in the present work, a conjugated polymer (PTTzFr) containing biosensor was constructed for the glucose analysis. The architecture showed a promising sensing system for biosensor application. For the preparation of the proposed sensor, polymer film was coated on graphite electrode surface and fabricated as a glucose biosensor with immobilization of glucose oxidase. The biosensor was successfully applied for the determination of glucose in beverage. Under optimized conditions, the proposed sensor served a low detection limit (12.8 × 10−3 mM), and high sensitivity (65.44 μAmM−1cm−2). To the best of our knowledge, a sensor design and ECD construction using electrochemically polymerized PTTzFr that shows superior properties for both systems were attempted for the first time, and this approach resulted in improved biosensor and ECD characteristics.