| Acute myocardial infarction is often accompanied by heart failure and thrombosis,with high morbidity and mortality,which is considered to be one of the main causes of human death.Therefore,there is an urgent need for an early and accurate diagnostic method to detect the markers related to acute myocardial infarction.Cardiac troponin I(cTnI),N-terminal pro-B-type natriuretic peptide(NT-proBNP),and D-dimer are typical representatives,which are positively correlated with the severity of acute myocardial infarction.Therefore,a novel quantum dot immunochromatographic test strip was designed and fabricated for the combined detection of these three markers,which can be used for early diagnosis of acute myocardial infarction.This article also explores the application of multi-color quantum dots in multi-index synchronous detection of single detection line,and is committed to achieving joint detection of more indicators.The main contents are as follows:(1)In this article,comb-like amphiphilic polymers were synthesized from methoxy polyethylene glycol and poly(maleic anhydride-alt-1-octadecene),and then oil-soluble Cd Se/Zn S quantum dots were encapsulated by the synthesized polymers to obtain water-soluble quantum dots with uniform particle size,good stability and quantum yield of 0.828.The self-made water-soluble quantum dots were coupled with cTnI,D-dimer and NT-proBNP antibodies respectively,and the optimal coupling process was screened by single factor experiment.The results showed that quantum dots were successfully coupled with cTnI,D-dimer and NT-proBNP.The quantum dots coupled with antibodies still retained good fluorescence properties,and the coupled antibodies still had activity and could specifically recognize the corresponding antigens.(2)In this article,the process of quantum dot test strips for three single indicators of cTnI,NT-proBNP and D-dimer was further optimized,and then the test strips were prepared based on the optimal process and their performance indicators were tested.The results showed that the linear correlation of cTnI,NT-proBNP,and D-dimer quantum dot test strips was good.The minimum detection limits were 0.0147 ng/m L,0.0165 ng/m L,and 0.01μg/m L,respectively,and the precision was less than 15%.The detection results of cTnI,NT-proBNP,and D-dimer quantum dot test strips were linearly fitted with the detection results of commercial single test strips,and the correlation coefficients R~2 were 0.99645,0.98096,and 0.96863,respectively,indicating that the established three detection methods have good accuracy for the detection of cTnI,NT-proBNP,and D-dimer in serum.(3)Based on the test strip process of a single index,a quantum dot test strip for the combined detection of cTnI,NT-proBNP,and D-dimer was constructed.The results showed that the linear correlation of cTnI,NT-proBNP and D-dimer in the combined test strips was good.The detection limits of cTnI,NT-proBNP,and D-dimer were 0.016 ng/m L,0.0097 ng/m L and0.012μg/m L,respectively.The precision was less than 15%,and the detection time was only 8min.Compared with the commercial single test strip,the self-made cTnI/NT-proBNP/D-dimer combined test strip can detect lower concentration points and has higher sensitivity.Compared with the hospital test results,the coincidence rate of negative and positive test results of self-made test strips was 100%.The test results of the self-made test strip were compared with the hospital test results by linear fitting.The correlation coefficients R~2 were 0.9953,0.99306,and0.98906,respectively,indicating that the self-made three-in-one quantum dot test strip has good accuracy for the simultaneous detection of cTnI,NT-proBNP,and D-dimer in serum.The combined detection method can effectively improve the accuracy of early diagnosis of acute myocardial infarction,and can reduce or avoid missed diagnosis and misdiagnosis,and has great clinical application value.(4)In addition,this article also explores the preliminary application of multi-color quantum dots in multi-index synchronous detection of single detection line.The Cd Se/Zn S quantum dots with emission wavelengths of 546 nm and 664 nm were coupled with the labeled antibodies of cTnI,NT-proBNP,and D-dimer,respectively,and the two-in-one test strips of cTnI/NT-proBNP,cTnI/D-dimer,and NT-proBNP/D-dimer were prepared.The standard curves of the three test strips were established by double-channel immunofluorescence analyzer.The linear correlation was good,and the two quantum dots did not interfere with each other.Compared with the self-made three-in-one test strip,the detection results of the two have good consistency,which preliminarily shows that the synchronous detection of the two indicators can be realized on one detection line,which provides a research basis for more indicators to carry out joint detection. |
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