Resistance choke type tiny particle and cell detection micro-fluidic chip and preparation method

Abstract

The invention discloses a resistance choke type tiny particle and cell detection micro-fluidic chip and a preparation method. A PDMS (polydimethylsiloxane) cover plate (1) and a substrate (2) are bonded to form the resistance choke type tiny particle and cell detection micro-fluidic chip, the shape and the size of the substrate (2) adapt to those of the cover plate, at least one pair of tiny electrodes (8) are arranged on the substrate (2), a micro-fluidic pipeline is arranged on the cover plate, one surface of the substrate (2) with the tiny electrodes and a contact surface of the micro-fluidic pipeline contacting with the substrate are bonded in an aligned manner, the micro-fluidic pipeline is closed and comprises a sample inlet (4), a main pipeline (7) and a sample outlet (3), and the main pipeline (7) is provided with a sample inlet pipeline (10), a shrinkage detection pipeline (11) and the narrowest portion (5). A complex pipeline and fluid control system needed by sheath fluid focusing technology is avoided, flow resistance increase effect caused by pipeline size reduction is avoided by optimized structural size parameters, and detection throughput and sensitivity are improved.

Description

technical field [0001] The invention relates to the technical field of biological cell detection, in particular to a structural design of a microfluidic chip used for micro particle / biological cell detection. Background technique [0002] The traditional Coulter counter uses a direct current signal to detect small particles passing through the micropore in the solution, and it has been developed into an instrument for blood cell analysis. Another device that detects tiny particles / cells is the flow cytometer. Flow cytometry uses optical detection methods to detect particles, which usually require fluorescent labeling of the particles to be tested, while non-labeled detection methods avoid interference and damage to the measured objects. For example, electrical impedance detection is non-labeled detection. kind of. The difference between the method of electrical impedance detection and Coulter counting is mainly that the electrical impedance detection uses an alternating cu...

AI Technical Summary

Problems solved by technology

The disadvantage of such a pipeline is that due to the long pipeline, the flow resistance is relatively large, or the pipeline is relatively wide to reduce the flow resistance, but the detection sensitivity is sacrificed, and the possibility of multiple particles / cells in the detection area is increased; or the pipeline is narrowed, Make the pipe width equal to or even smaller than the outer diameter of particles / cells to improve detection sensitivity, but the flow resistance is too large, the detection flux is very low, and it is easy to block the pipe

If the electrode is far away from the detection site, although the detection sensitivity can be improved by increasing the excitation voltage, the higher voltage may cause damage to the measured particles such as cells.

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