Poly(o-aminophenol) prepared by Cu(ii) catalyzed air oxidation and its use as a bio-sensing architecture

Abstract

A novel procedure for the preparation of organosoluble poly(o-aminophenol) is described. The method pertains to the reduction of CuBr₂ with o-amino phenol (OAP) at room temperature. The air oxidation of the Cu(I) species to Cu(II) facilitated the formation of poly(o-aminophenol) (POAP) in repeated cycles. The obtained polymer, soluble in common organic solvents such as dimethylformamide, acetone, and chloroform, was characterized by spectral analyses. It was found that both quinoid and benzoid structures were present in the polymer chain. Poly(o-aminophenol) architecture was then applied as an immobilization matrix to obtain a long-lived and fast response bio-sensing system. Glucose oxidase (GOx) was utilized as a model enzyme for the detection of glucose in beverages. After the optimization studies, the surface characterization of POAP/GOx was performed by scanning electron microscopy (SEM) measurements. Under the optimized conditions, the biosensor exhibited a rapid response (2 s), a low detection limit (0.02 mM), and high sensitivity (79.80 μA mM⁻¹ cm⁻²). The K^app_M value was determined as 0.16 mM. Furthermore, there was no considerable activity loss for 15 days for the POAP/GOx biofilm indicating excellent recovery as tested with real samples.