Bioorthogonal reaction is a fast chemical reaction having good selectivity and specificity, covalent bond can be formed in a biological system without interfering any external chemical. Herein, we have developed a new chemical method in which grafted trans-cyclooctene (TCO) derivatives (a bioorthogonal reactive motif) into PAAIO in a aqueous solution, then followed by injection of tetrazine derivatives labeled with a green fluorescent dye as a chemical reporter. The [4+2] cycloaddition reaction between TCO and tetrazine is called as IEDDA. The solubility is increased by using PEGylated groups. In the future, we have an idea to do bioorthogonal reaction in vitro.