DNA (deoxyribonucleic acid) biosensor chip based on nanometer magnetic bead technique and experimental method thereof

Abstract

On a conventional T-shaped glass chip, a permanent magnet is utilized to fix and decorate a nanometer magnetic bead of a DNA probe in a separation channel of a chip; the rapid, sensitive, high-specific, high-stability, low-cost separation detection on the DNA is realized by utilizing electric drive sampling and combining a laser induced fluorescence detector or an electrochemical detector, thus solving the defects that the time of separating and detecting the DNA by utilizing a microfluidic chip is long, the separation effect is poor, the sensitivity is low, the specific is poor and the stability is poor and the like; the interface manufacturing is avoided by an electric sampling manner; the influence of dead volume is removed; and the sample use amount is reduced in a narrower and uniform micro pipeline, and meanwhile the lower detection limit is ensured.

Description

technical field [0001] The invention relates to a biosensor chip for chip separation and detection of DNA and a preparation method thereof, in particular to a microfluidic DNA biosensor chip based on nano magnetic bead technology and a preparation method thereof. Background technique [0002] At present, the commonly used methods for separation and detection of DNA based on chips include chip gel electrophoresis and chip gel-free sieving electrophoresis. The former has disadvantages such as tedious and time-consuming gel column preparation process, short column life, and easy clogging; the latter has no clear rules for the selection of non-gel media system, and the existence of non-gel media may affect subsequent detection. In addition, both have shortcomings such as long separation pipelines, inability to separate DNA with the same number of bases, and inability to distinguish single-base mismatches. [0003] In recent years, chips with nanopipe structures have been used f...

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Problems solved by technology

However, due to the relatively cumbersome fabrication of microelectrodes, high process requirements, and high cost, it cannot be popularized.

In addition, some people try to immobilize magnetic nanoparticles in microchannels with permanent magnets, and use pressure pumps to transport DNA to achieve DNA separation, enrichment and detection, but some chip pipeline structures are more complex, and some microchannels for immobilizing magnetic beads are wider. , affecting the detection limit, and the interface between the chip and the pressure pump is troublesome to make, and the pressure control micro-flow is not accurate enough

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