Sensetive detection of glutathione (GSH) by using dsDNA-templated copper nanoparticles (dsDNA-CuNPs) as electrochemical reporters: review

An electrochemical method for the detection of GSH is adoption of DNA-templated CuNPs as electrochemical reporters. GSH and Cu ions interact eachother strongly, so they will make great hindrances to DNA-templated formation of CuNPs on the electrode surfaces, and the electrochemical signals will decrease. Although this method exhibits desirable selectivity and producibility, shows superior sensitivity, but remains problematic, because of weak fluorescence and poor stability. In order to solve this problem, a novel concatemetris dsDNA-CuNPs strategy was proposed by introducing the rolling circle replication (RCR) techniques into CuNPs synthesis. A short oligonucleotide primer could trigger RCR and be further converted to a long concatemeric dsDNA-CuNPs.These dsDNA-CuNPs can emit intense fluorescence in the range of 500-650nm under a 340nm excitation. Their sensitivity improved with ~10000 folds amplication, and fluorescence signal was detected to reserve ~60% at 25h after formation, revealing ~2 times enhanced stability.