Abstract: The present disclosure provides a potassium dihydrogen phosphate (KDP) frequency-doubling crystal structure, including a crystal fixing structure, a KDP crystal, a ? polarization tube, and a ? polarization tube; where a ?-polarized laser with a central wavelength of 800 nm enters the KDP crystal through the ? polarization tube, and the KDP crystal converts the ?-polarized laser with a central wavelength of 800 nm into a ?-polarized laser with a central wavelength of 400 nm by frequency doubling and then outputs the ?-polarized laser from the ? polarization tube. Close end bevels of the ? polarization tube and the ? polarization tube are designed into a Brewster angle. The KDP crystal is placed in a vacuum-sealed cavity formed by the ? polarization tube, the ? polarization tube, and the crystal fixing structure, which eliminates a complicated process of crystal coating and prevents the KDP crystal from deliquescing in air.

Abstract: The present invention relates to a method of using a microfluidic chip comprising introducing a gas into the microfluidic chip to replace the liquid that has been introduced into the microfluidic chip and forming a micro-reaction chamber in the form of a liquid-in-gas in the microfluidic chip. The present invention also relates to a method for obtaining assay data, a computer program product embodied in a computer-readable medium and a kit. The methods described in the present invention are easy to operate, low cost, versatile, enabling rapid exchange of fluids, achieving efficient separation and capture of single particles with high purity. In addition, the methods can avoid clogging the chip and facilitate recycling.

Abstract: A quantitative analysis method based on air pressure measuring, which can be used for the high-sensitivity quantitative detection of various targets i.e. inorganic ions, small molecules and biological macromolecules such as proteins, DNA, and even viruses, bacteria, cells, etc. The present invention catalyzes hydrogen peroxide to generate a large amount of gas using enzymes or nanoparticles, etc.; converts the target molecule detection signal into a gas pressure intensity signal; achieves signal amplification; and finally converts the pressure change into an electrical signal to conduct a reading through an air pressure meter, thereby achieving high-sensitivity quantitative detection. The feasibility, wide applicability and reliability of the present invention are certified through three different detection systems, i.e. an ELISA system, a DNA hydrogel system and a functional DNA sensor system, respectively, using an air pressure meter.