文摘
The authors report on a fast chemiluminescence (CL) assay for the food additive sodium tripolyphosphate (STPP). It is based on the use of gold nanoflowers (AuNFs) bifunctionalized with luminol and chitosan that act as a CL probe and a molecular recognitions systems because chitosan can bind STPP. In the absence of STPP, the luminol-chitosan-AuNF CL system is triggered by addition of H2O2 and Co(II) ions. However, on addition of STPP, modified AuNFs bind STPP and aggregate. This suppresses CL. Under optimized conditions, the system responds to STPP in the 0.7 to 700 μM concentration range, and the limit of concentration is as low as 0.5 μM. This is lower than that of other analytical techniques for STPP. The method was applied to the determination of STPP in (spiked) ham samples, and recoveries ranged from 98% to 107% with a relative standard deviation of <5.0%.