Synthesis of nucleus-satellite like Ag nanoparticles based on dielectric barrier discharge system for prolonged chemiluminescence imaging of mercury ions

•“Nucleus-satellite” like POSS-Ag NPs were firstly synthesized by dielectric barrier discharge system within 40 min.•The POSS-Ag NPs specially showed enhanced chemiluminescence intensity due to increased specific surface area and SPR characteristics.•The presence of Ag0/Ag+ and O2/·O2– charge cycling transfer on the surface of POSS-Ag NPs further led to the prolonged CL emission.•POSS-Ag NPs - luminol CL system was used for the specific imaging detection of mercury ions based on the inhibition of catalytic and SPR effects caused by Hg-Ag alloys.