An enzyme-free electrochemiluminescence biosensor for ultrasensitive assay of Group B Streptococci based on self-enhanced luminol complex functionalized CuMn-CeO2 nanospheres.
Herein, a novel and pragmatic electrochemiluminescence (ECL) biosensing method was developed for ultrasensitive and specific detection of Group B Streptococci (GBS) by combining self-enhanced luminol complex functionalized CuMn-CeO2 (CuMn-CeO2-PEI-luminol) with MNAzyme-mediated target-recycling amplification. First, the efficient self-enhanced PEI-luminol luminophore was prepared by combining PEI co-reactant with luminol in one molecular, which shortened electron transfer distance and enhanced ECL signal. And CuMn-CeO2 was applied to load a large number of PEI-luminol and strengthen luminous efficiency of luminol by the high catalytic activity toward H2O2 oxidation. Then, target-driven MNAzyme system was used to realize the circulation of GBS nucleic acid sequence, producing plentiful triggers to initiate the hybridization reaction on the surface of electrode. The developed enzyme-free ECL biosensor showed ultra-sensitivity for target DNA detection with detection limits of 68 aM (synthetic DNA) and 5 × 102 CFU mL-1 (genomic DNA extracted from GBS strain). More importantly, this biosensor was successfully applied for detection of genomic DNA of GBS extracted from clinical vaginal/anal swabs as low as 320 copies. Thus, this proposed strategy might be an pragmatic ECL platform for ultrasensitive and specific detection of GBS in clinical vaginal/anal swabs.
['Ling|Jiaji|J|', 'Zhao|Min|M|', 'Chen|Fengjiao|F|', 'Zhou|Xiaoyan|X|', 'Li|Xiaosong|X|', 'Ding|Shijia|S|', 'Tang|Hua|H|']
D015374:Biosensing Techniques D002384:Catalysis D003300:Copper D004247:DNA D055664:Electrochemical Techniques D006861:Hydrogen Peroxide D057230:Limit of Detection D008163:Luminescent Measurements D008165:Luminol D008345:Manganese D053768:Metal Nanoparticles D054118:Nanospheres D013291:Streptococcus
Electrochemiluminescence Group B Streptococci MNAzyme CuMn-CeO(2)-PEI-luminol Intramolecular co-reaction