Chip, preparation method therefor, and application thereof

A method for preparing a chip, comprising:

• obtaining a substrate having a surface grafted with an amino group, the amino group being a primary amino group or a secondary amino group;
• linking a first compound to the surface via the amino group, the first compound comprising the following structure:
• wherein R1 and R2 are each independently selected from —OH and C1-C5 alkoxy, and n is 1 or 2;
• optionally wherein R1 and R2 are each independently selected from —OH, —OCH3 and —OCH2CH3;
• linking a polymer to the first compound, wherein the polymer comprises a plurality of structural units, at least one of the structural units comprising an amino group;
• and
• linking a nucleic acid sequence to the polymer via a linker group, wherein the linker group comprises a first terminus capable of linking to the nucleic acid sequence and a second terminus, preferably the second terminus comprises at least one of an —NHS group, an epoxy group and an isocyanate group, preferably the nucleic acid sequence has a -DBCO or —N3 modification, and the first terminus comprises -DBCO or —N3.