Fluorescence analysis method based on HCR and cation exchange reaction of hydrogel

[0036] Embodiment 1: in combination with figure 1 , Silanization of glass sheets and preparation of hydrogel arrays

[0037] (1) Preparation of silanized substrates: Ultrasonic cleaning of ordinary glass sheets with acetone, ethanol and deionized water for 2 minutes respectively, blowing dry with nitrogen gas, and then treating them with a plasma cleaner to activate surface hydroxyl groups, and then putting them into 0.05% (v / v) silylating agent (3-acryloyloxypropyltrichlorosilane) in anhydrous toluene for 1 hour in a nitrogen-filled glove bag. Afterwards, the glass slides were cleaned with toluene, ethanol and deionized water, blown dry with nitrogen gas, and cured in an oven at 100°C for 2 hours, and stored in a dry box for future use.

[0038] (2) Preparation of hydrogel array: first prepare the prepolymer solution, 7.5% (v / v) PEG-DA (MW700), 22.5% (v / v) 20mM PEG-DA aqueous solution (MW 3400), 40% (v / v) PEG (MW 200), 15% (v / v) 20mM Acryl-PEG-COOH in water, and 10%

[0039] Embodiment 2: in combination with figure 2 , taking miRNA-21 as an example to illustrate that the fluorescence analysis method based on hydrogel HCR and cation exchange reaction is used for the detection of microRNA

[0040] (1) Probe modification: Activate the carboxyl group of the hydrogel array with 0.4M EDC / 0.1M NHS MES buffer (25mM, pH5.5) at room temperature for 40 minutes, add 10μL of 0.5μM capture solution to each array spot after washing Probe CP, placed in a humid chamber overnight at room temperature.

[0041] (2) Hybridization chain reaction: first, drop 10 μL containing different concentrations of standard miRNA or samples to be tested at each array point, incubate at 37°C for 1 hour, then add 10 μL of an equal volume mixed solution of 1 μM hybridization chain hairpin H1 and H2 dropwise after washing, Incubate at 37°C for 2 hours, the DNA single strand of the capture probe triggers the hybridization chain reaction between H1 and H2, and assembles at the se