determining the pka value of the fourth generation poly(propylene imine) dendrimer functionalized with 4-carboxyphenylboronic acid by ph titration method

In this study, poly (propylene imine) dendrimer was synthesized up to the fourth generation. then it was modified by amidation of 4-carboxyphenylboronic acid (4-cpba) carboxylic acid groups with amines of the fourth generation highly-branched polymer. the successful synthesis of the highly-branched polymer was confirmed by 1h nmr analysis, and the structure of the highly-branched polymer modified with 4-cpba was confirmed by ft-ir analysis. uv-vis analysis also was used for the pure samples of 4-cpba and hp-cpb. emphasizing the fact that materials with phenylboronic acid groups should have a pka value slightly higher than the physiological ph of the body in order to be used as a glucose sensor. as a result of this research, the pka value for functionalized dendrimer with phenylboronic acid (hp-cpb) was determined to be 7.8 by the ph titration method.