Sensitive and rapid chemiluminescence detection of propranolol based on effect of surface charge of gold nanoparticles

We report a label-free, gold nanoparticles (AuNPs)-based chemiluminescent method for propranolol assay. The method relies upon the catalytic activity of unmodified AuNPs on the luminol-H2O2 chemiluminescence (CL) reaction, and the interaction of unmodified AuNPs with propranolol. The surface charge property of AuNPs directly affects their catalytic performance for CL reaction, and the interaction of AuNPs with propranolol can change AuNPs׳ surface charge property and induce the AuNP aggregation, and after aggregation the catalytic activity of AuNPs on the luminol-H2O2 CL reaction is greatly enhanced. During the assay, no covalent functionalization of AuNPs is required. The assay is homogenous. The detection limit of propranolol (3σ) was estimated to be as low as 6.6×10−12 g mL−1, and the sensitivity was 4 orders of magnitude better than that of known CL methods for the detection of propranolol. This AuNPs-based CL method offers the advantages of being simple, cheap, rapid, and sensitive.