A new and efficient synthetic route to hydroxymethylated-3

4-ethylenedioxylthiophene (EDOT-MeOH) was developed by a simple four-step sequence

and its global yield was approximately 41.06%. The poly(hydroxymethylated- 3

4-ethylenedioxylthiophene) (PEDOT-MeOH) film was electrosynthesized in aqueous sodium dodecylsulfate micellar solutions and characterized by different methods. The EDOT-MeOH possessed better water solubility

and lower onset oxidation potential than EDOT. The as-obtained PEDOT-MeOH film displayed good reversible redox activity

stability and capacitance properties in a monomer-free electrolyte

especially the good solubility of PEDOT-MeOH film in strong polar organic solvents such as dimethyl sulfoxide and tetrahydrofuran created a potential application in many different fields. Fluorescent spectra indicated that PEDOT-MeOH was a yellow-green-light-emitter with maximum emission at 568 nm. The as-formed PEDOT-MeOH film had good biocompatibility and was used for fabricating the electrochemical vitamin C biosensor. The proposed biosensor showed a linear range of 3 × 10

−6

mol/L to 1.2 × 10

−2

mol/L with the detection limit of 1 μmol/L

a sensitivity of 95.6 μA (mmol/L)

−1

cm

−2

and a current response time less than 10 s and a fairly good stability (The relative standard deviation was 0.43% for 20 successive assays

the proposed biosensor still retained 93.5% of bioactivity after 15 days storage. This result indicated that the prepared PEDOT-MeOH film as immobilization matrix of biologically-active species could be a promising candidate for the design and application of biosensor.