Chemiluminescence “turn-on” detection of tyrosinase activity via in situ generation of dopamine based on a lucigenin and riboflavin system†
Abstract
A lucigenin and riboflavin chemiluminescence system was utilized for the first time to achieve the “turn-on” detection of tyrosinase activity via an in situ reaction between tyrosinase and tyramine to generate dopamine. Tyramine is the model substrate of tyrosinase and dopamine is the product. Since dopamine can enhance the chemiluminescence of the lucigenin and riboflavin system, the chemiluminescence of lucigenin and riboflavin can be enhanced in the presence of both tyramine and tyrosinase. In the presence of 6.0 U mL−1 tyrosinase, the chemiluminescence intensity was nearly 10 times higher than that of lucigenin, riboflavin and tyramine mixtures. Therefore, this method has been applied in the chemiluminescence “turn-on” detection of tyrosinase activity in the range of 0.1–8.0 U mL−1 with the limit of detection (LOD) of 0.028 U mL−1. This overall process of sensing tyrosinase activity took nearly 30 min. Moreover, it had high selectivity in the chemiluminescence “turn-on” detection of tyrosinase activity towards other enzymes, such as glucose oxidase, lysozyme, trypsin or alkaline phosphatase. When 1.0, 2.0 and 5.0 U mL−1 tyrosinase were added to the diluted serum samples, recoveries were in the range of 100.2%–104.1%. This indicates that this method for the chemiluminescence “turn-on” detection of tyrosinase activity has high sensitivity, selectivity, accuracy and fast response time.