Enhanced chemiluminescence detection of glutathione based on isoluminol-PSM nanoparticles probe

In this paper, a new chemiluminescence (CL) strategy was constructed for the determination of physiological thiols by using an isoluminol labeled nano-probe. The amino group on the surface of the magnetic beads (MBs) were converted into pyridyl disulfide groups by treatment with N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP), in the meantime, isoluminol and thiolated signal DNA were labeled on the surface of the polystyrene microspheres (PSMs). By treating the SPDP activated MBs with the modified PSMs, isoluminol molecules on the surface of the PSMs, along with the thiolated signal DNA, were attached to the surface of the MBs through disulfide bonds to form a CL probe. In the presence of glutathione (GSH), the disulfide bonds could be cleaved readily. The isoluminol molecules modified on the surface of the PSMs released from the CL probes were detached by magnetic separation and transferred to the dark closet for CL detection of isoluminol-H2O2-HRP system. Using GSH detection as a model, we prove a linear dose response in the range from 5 × 10(-10) to 8 × 10(-8)M. The detection limit of this trial for GSH determined is 5 × 10(-10)M. The proposed design was successfully applied to the extracts of K562 cell for intracellular thiols detection, the average amount of thiols was about 4.114 × 10(-13)M per K562 cell.