Enzyme-linked immunosorbent assay（ELISA） as a conventional method for protein quantification has its characteristic properties,however,it is challenging to implement excellent portability and sensitivity at the same...Enzyme-linked immunosorbent assay（ELISA） as a conventional method for protein quantification has its characteristic properties,however,it is challenging to implement excellent portability and sensitivity at the same time.In this study,we described a pH ELISA using synthetic melanin nanoparticles（SMNPs） for the co-immobilization of glucose oxidase（GOx） and second antibody（Ab_2） as signal labels,portable pH meter as signal readout device for point-of-care testing（POCT） of cardiac troponin I（cTnI）.In accordance with the varying amount of cTnI,following sandwich type immunoassay,proportional SMNPs-GOx-Ab_2 were immobilized specifically resulting in corresponding decrease of pH values owing to GOx loaded on SMNPs can high-efficiency convert glucose into gluconic acid.This assay is easy-to-use,portable,sensitive and able to realize POCT,affording a linear range from 0.5 pg/m L to 10 ng/m L and low limit of detection（LOD） of 0.15 pg/m L towards cTnI,which was demonstrated the significant promising in the early diagnosis and screening of acute myocardial infarction.展开更多
基金the National Natural Science Foundation of China(Nos.21245007 and 81000976) for the financial support
文摘Enzyme-linked immunosorbent assay（ELISA） as a conventional method for protein quantification has its characteristic properties,however,it is challenging to implement excellent portability and sensitivity at the same time.In this study,we described a pH ELISA using synthetic melanin nanoparticles（SMNPs） for the co-immobilization of glucose oxidase（GOx） and second antibody（Ab_2） as signal labels,portable pH meter as signal readout device for point-of-care testing（POCT） of cardiac troponin I（cTnI）.In accordance with the varying amount of cTnI,following sandwich type immunoassay,proportional SMNPs-GOx-Ab_2 were immobilized specifically resulting in corresponding decrease of pH values owing to GOx loaded on SMNPs can high-efficiency convert glucose into gluconic acid.This assay is easy-to-use,portable,sensitive and able to realize POCT,affording a linear range from 0.5 pg/m L to 10 ng/m L and low limit of detection（LOD） of 0.15 pg/m L towards cTnI,which was demonstrated the significant promising in the early diagnosis and screening of acute myocardial infarction.
