A highly selective amperometric sensor for ascorbic acid based on mesopore-rich active carbon-modified pyrolytic graphite electrode

A kind of new mesopore-rich active carbon (MRAC) was firstly prepared by carbonizing bamboo micro-particles, which was utilized for constructing MRAC-modified pyrolytic graphite electrode (MRAC/PGE). The electrochemical behavior of ascorbic acid (AA) was in detail investigated at the MRAC/PGE. The proposed MRAC/PGE showed an excellent electrocatalytic response towards AA oxidation in neutral buffer solution. The oxidation potential of AA significantly decreased at MRAC/PGE. The oxidation current of AA obtained at the MRAC/PGE is 4.6-fold higher than that of the bare PGE. Using amperometric method, the anodic current is linear with AA concentration in the range of 0.5–2000 μM, with a detection limit about 0.3 μM. Furthermore, the proposed electrode can also avoid major interferences such as dopamine, uric acid, urea, and so on. This new method has been successfully applied for AA assay in urine and pharmaceutical preparations.