Ultrasensitive determination of ascorbic acid by using cobalt oxyhydroxide nanosheets to enhance the chemiluminescence of the luminol-H2O2 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-H2O2 CL system. The results showed that ultrathin CoOOH nanosheets as a catalyzer remarkably improved the CL intensity of the CoOOH-luminol-H2O2 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-1, and the limit of detection was 39 fmol L-1. Moreover, the proposed CL system was successfully applied in the determination of AA in medicinal tablets with satisfactory results.