Ultrasensitive determination of ascorbic acid by using cobalt oxyhydroxide nanosheets to enhance the chemiluminescence of the luminol-HO system.

Ascorbic acid (AA) as an essential vitamin in the human body participates in various physiological reactions and plays a key role in many biochemical processes. Therefore, it is of vital importance to monitor and quantify AA in commercial tablets, beverages and food. In this work, a rapid and ultrasensitive chemiluminescence (CL) system for the detection of AA was developed, in which ultrathin cobalt oxyhydroxide (CoOOH) nanosheets were applied in the conventional luminol-HO CL system. The results showed that ultrathin CoOOH nanosheets as a catalyzer remarkably improved the CL intensity of the CoOOH-luminol-HO system, up to about 1400-fold. Under the optimized conditions, the CL inhibition efficiencies increase linearly with the concentrations of AA in the range of 1-500 pmol L, and the limit of detection was 39 fmol L. Moreover, the proposed CL system was successfully applied in the determination of AA in medicinal tablets with satisfactory results.