High-performance non-enzymatic glucose sensors based on porous Co3O4 synthesized by coprecipitation method with the different precipitants

The glassy carbon electrode (GCE) embellished with porous Co3O4 as a non-enzymatic amperometric sensor is applied to the determination of glucose concentration. Spinel porous Co3O4 samples are synthesized by a facile coprecipitation method using sodium oxalate (SO) and ammonia water (AW) as different precipitants. The influence of the different precipitants on the morphology, structure, and catalytic performance is systematically studied. The electrochemical measurements reveal that the Co3O4 synthesized using sodium oxalate (SO) precipitant exhibits higher sensitivity of 1060.1 μA mM−1 cm−2 and better long-term stability with maintain in 90% after 30 days than the Co3O4 (37.25 μA mM−1 cm−2) synthesized using ammonia water (AW) precipitant. The limit of detection for Co3O4 (using SO as precipitant)/GCE is estimated to be 0.32 μM less than 0.51 μM of Co3O4 (using AW as precipitant)/GCE (S/N = 3). The reason may be that theCo3O4 (using SO as precipitant) has fluffy porous structure and higher specific surface area than the Co3O4 (using AW as precipitant), which can provide the large electroactive sites and improve the diffusion of electrolyte ions and reduces their diffusion resistance.