摘要
Sensitive detection and precise quantitation of trace-level crucial biomarkers in a complex sample matrix has become an important area of research.For example,the detection of high-sensitivity cardiac troponin I (hs-cTnI) is strongly recommended in clinical guidelines for early diagnosis of acute myocardial infarction.Based on the use of an electrode modified by single-walled carbon nanotubes (SWCNTs) and a Ru(bpy)32+-doped silica nanoparticle (Ru@SiO2)/tripropylamine (TPA) system,a novel type of electrochemiluminescent (ECL) magnetoimmunosensor is developed for ultrasensitive detection of hs-cTnI.In this approach,a large amount of[Ru(bpy)3]2+is loaded in SiO2(silica nanoparticles) as luminophores with high luminescent efficiency and SWCNTs as electrode surface modification material with excellent electrooxidation ability for TPA.Subsequently,a hierarchical micropillar array of microstructures is fabricated with a magnet placed at each end to efficiently confine a single layer of immunomagnetic microbeads on the surface of the electrode and enable 7.5-fold signal enhancement In particular,the use of transparent SWCNTs to modify a transparent ITO electrode provides a two-order-of-magnitude ECL signal amplification.A good linear calibration curve is developed for hs-cTnI concentrations over a wide range from 10 fg/ml to 10 ng/ml,with the limit of detection calculated as 8.720 fg/ml (S/N=3).This ultrasensitive immunosensor exhibits superior detection performance with remarkable stability,reproducibility,and selectivity.Satisfactory recoveries are obtained in the detection of hs-cTnI in human serum,providing a potentia analysis protocol for clinical applications.
基金
The authors acknowledge financial support from the National Natural Science Foundation of China(Grant Nos.62001460,31971368,12202461,and 22104148)
the Guangdong Regional Joint Funds for Young Scientists(Grant Nos.2020A1515110201 and 2020A1515110368)
Guangdong Provincial General Funding(Grant No.2021A1515220156)
Guangdong Basic and Applied Basic Research Funding-Regional Joint Fund(Grant No.2020B1515120040)
Shenzhen Science and Technology Research Funding(Grant Nos.JSGG20201103153801005,JSGG20191115141601721,ZDSYS20220527171406014,JCYJ20220818101412027,JCYJ20200109115635440,and JCYJ 20200109115408041).
