First, we investigated the catalytic effect of as-prepared IGNPs on CL of luminol-[H.sub.2][O.sub.2] reaction with a flow-injection CL setup (Model MPI-B multiparameters chemical analysis system, Xi'an Remax Analytical Instrument Co., Xi'an, China), and compared with that of spherical Au-NPs and Au(III).
Sequence (c)-modified IGNPs probes were prepared similar to literature method (19).
0.2 mmol/L luminol (in 0.01 mol/L NaOH) and 0.01 mol/L [H.sub.2][O.sub.2] were injected into the system, which were catalyzed by IGNPs probe to produce enhanced CL.
The experiments also revealed that very weak, enhanced light was emitted from the system after this protocol in the absence of sequence 2 or in the absence of the DNA-functionalized IGNPs (sequence 3), or in the absence of IgG or in the absence of IGNPs-functionalized anti-IgG.
For comparison, we also used the spherical gold nanoparticles as label instead of IGNPs to carry out DNA detection and IgG immunoassay following the same protocols.