| The determination of tumor markers, DNA and cancer cells, and the diseases relevant to DNA, plays an important role in screening for a disease, in diagnosing a disease, and in determining the prognosis of a disease. It also offers opportunities for understanding fundamental biological processes involved in disease progression, and all researchers take mornitoring biomolecules as an important task. Recently, to achieve the sensitive, accurate, and rapid detection of cancer, countries biologists and medical scientists make innovations in mornitoring methods, and some significant achievements have been obtained.In this paper, we focus on electrochemiluminescences(ECL) and photoelectrochemical(PEC) methods, and Cd Te QDs and Zn O semiconductor nanomaterials with excellent photoelectric property were prepared. To obtain the better signal, they were immobilized onto the graphene, carbon nanotube, and Si O2 nanomaterials. Our biosensors showed wide linear range, good specificity and stability. And homemade portable transformers and multi-channel multiplex switch were combined to develop low-cost, high-throughput real-time detection system. The main research is as follows:(1) A highly sensitive electrochemiluminescence(ECL) immunosensor for the detection of prostate specific antigen(PSA) was designed using biofunctionalized magnetic graphene nanosheets(G@Fe3O4) as immunosensing probes and Cd Te quantum dots coated silica nanospheres(Si/QDs) as signal amplifica-tion labels. In this work, a sandwich-type immunosensor was fabricated. The analyte was detected in a home-made flow injection ECL(FI-ECL) cell through the immunosensor. Owing to the signal amplification of G@Fe3O4 composite and Si/QDs, the ECL measurement showed a great increase in detection signals compared with the unamplified method.(2) We report on a disposable microdevice suitable for sandwich-type electrochemiluminescence(ECL) detection of prostate specific antigen(PSA). The method is making use of Zn O quantum dots dotted carbon nanotube(Zn O@CNT) and simply electrochemical reduced Pt/Au alloy. The latter was selected as immunosensing probe to modify screen-printed carbon electrode, due to its excellent electrical property. For further ultrasensitive, low-potential and stable ECL detection, Zn O@CNT composite was first synthesized using a facile solvothermal method, and employed as signal amplification label.(3) Zn O/graphene(Zn O/G) composite and S6 aptamer were employed to sensitive PEC strategy for the specific detection of SK-BR-3 cancer cells based on a portable indium tin oxide microdevice. Zn O/G composite was synthesized using a facile ultrasonic method, and then applied to improve the PEC performance due to the unique hollow structure of Zn O naospheres and the superior properties of graphene. Subsequently, S6 aptamer was applied to this specific detection of SK-BR-3 cancer cells.(4) We constructed a highly sensitive ECL immunosensor for the detection of carcinoembryonic antigen(CEA) based on a disposable device. Initially, nanoporous Ag was immobilized on the screen-printed carbon electrode, showing large specific surface area to immobilize more Ab1. On the other hand, it would be an effective way to integrate Sn O2 QDs with Pt Ru alloy as ECL signal magnified elements to label Ab2 for constructing sensitive ECL biosensor with a particular analytical sensing design. The Sn O2 QDs functionalized Pt Ru composite labels were brought to the NPS modified electrode surface through a subsequent “sandwich” immunoreaction, which allowed sensitive detection of CEA, with detection limits of 0.72 pg·m L-1. |
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