Method for determining the presence or absence of a biomarker
申请人:Gwenin Christopher David
公开号:US09945852B2
公开(公告)日:2018-04-17
A method of determining the presence or absence in a sample of a biomarker, the method comprising: (a) linking an antigen to colloidal gold to provide a gold-antigen species; (b) contacting the gold-antigen species with the sample; (c) adding a diagnosis agent to the sample; and (d) observing the color of the sample.
Mycolic acid antigen containing liposomes, and an electrode immobilised antigens of tuberculous mycobacterial origin are produced. A diagnostic sample from a human suspected of having tuberculosis is diluted and divided into first and second samples. A control sample comprising the first sample and a redox probe is exposed to the liposomes. A test sample comprising the second sample and a redox probe is exposed to liposomes not containing mycolic acid antigens. The control sample is contacted with the immobilised antigens to allow antibodies therein to bind to the antigens. The test sample is contacted with the immobilised antigens to allow any antibodies therein to bind to the antigens. The degree of binding in the samples is compared by electrochemical impedance spectroscopy. Any observed lesser binding by the control sample is an indicator of antibodies to the antigens in the diagnostic sample, indicating tuberculosis in the human.
Immobilising isolated mycolic acid antigens of tuberculous mycobacterial origin or a synthetic analogue thereof on a screen-printed electrode by binding of the antigens to a self-assembled monolayer comprising a thiolated hydrophobic substance to produce immobilized mycolic acids antigens in the form of a mycolic acid antigen-containing self-assembled monolayer coating on a surface of the electrode