| Hepatitis B, hepatitis C and AIDS are three common infectious diseases that seriously threaten human health. During clinical blood transfusion and blood donation,the Medical and Sanitary Institution must follow the provisions of the Ministry of Health to carry on mandatory examination on these three kinds of infectious diseases. At present, there are lots of clinical and experimental methods for detecting HBV、HCV and HIV,but each has shortcomings. For example, low detection sensitivity, cannot achieve synchronous quantitative detection require special testing instruments or timeconsuming, etc. Considering the deficiency of these existing test methods, we developed a quantum dot(QD) based immunochromatography test strip(ICTS) by combining quantum dot labeling technology with immunochromatography to realize synchronous quantitative detection of hepatitis B, hepatitis C and AIDS.In this study, EDC/NHS are used as cross-linkers to activate carboxyl QDs. Activated QDs with emission wavelengths at 530 nm, 576 nm and 620 nm are coupled to hepatitis B surface antibody, HCV antigen and HIV antigen respectively.Quantum dots coupling compound are added to a glass fiber membrane to obttain the conjugate pad. Hepatitis B surface antigen polyclonal antibody, HCV core antigen and HIV antigen are coated onto the NC membrane as testing line, sheep anti mouse IgG as control line. Then the sample pad, conjugate pad, NC membrane and absorbent pad are pasted on the PVC backing plate in sequence to make up a quantum dots based ICTS.Fluorescence intensity of test line and control line on a single strip are both measured by a fluorescent reader. Different concentration of HBsAg, HCV antibody and HIV antibody captured on the test line have different fluorescence intensity of QDs both on test line and control line, and the results are recorded by the ratio of the fluorescence intensities of test line and control line(T/C ratio). Synchronous quantitative detection of HBV, HCV ang AIDS are realized by the standard curve drawed according to the T/C ratio.The research results of this article:(1) 58 clinical samples(HBsAg positive 38, HBsAg negative 20) were simultaneously detected with the quantum dots based ICTS and the colloidal gold based test strip and ELISA kit respectively. The results show that the accordance rates, sensitivity, specificity of quantum dots based ICTS were 98.1%,100%, 95%, the minimum detection limit and detection time is 2.6ng?ml,10 minutes. It is faster than ELSIA, and has high level of sensitivity compared with colloidal gold based test strip.(2) When HbsAg and HIVAb were were simultaneously detected with the quantum dots based ICTS, the negative accordance rates for HBsAg and HIVAb were 94.2%, 89.6%; the positive accordance rates for HBsAg and HIVAb were 87.2%, 83.7%; the detection sensitivity for HBsAg and HIVAb were 95%, 90.1%; the detection results of HBsAg and HIVAb show that the cofficient variation(CV) were 12%, 14.5%, both less than 15%.(3) The exploration experiment shows that when use a quantum dots based ICTS to detect HBsAg and HCV Ab and HIVAb synchronously and quantitatively, the minimum detection limit of these three indicators were 2.6 ng/ml, 15 ng/ml and 10 ng/ml.(4) The stability, specificity and sensitivity of the quantum dots based ICTS which stored at 4℃ did not change obviously after one month.In this study, we combine quantum dot labeling technology with immunochromatography, use quantum dots instead of traditional colloidal gold to develope a quantum dots based ICTS successfully.This test strip can realize synchronous quantitative detection of hepatitis B, hepatitis C and AIDS and very suitable for the simultaneous quantitative detection of blood and other samples. This quantum dots based ICTS makes the detection of blood-borne diseases more simple, rapid and economic. A synchronous quantitative membrane phase detection method with high level of specificity, sensitivity and stability is also established. |
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