1. Department of Materials Science and Engineering, Seoul National University, Seoul 151‐742, Korea;2. These authors equally contributed to this work.
Abstract:
A new pH sensor, which consists of a fluorophore and gold nanoparticle (AuNP) attached to each chain end of a pH‐sensitive polysulfonamide, respectively, is synthesized, and its pH sensitivity is investigated in terms of the fluorescent quenching efficiency of AuNP. Since the pH‐sensitive polymeric linker exhibits a pH‐induced coil–globule transition that is rapid enough to show a typical two‐state transition, it shows drastic on‐and‐off quenching efficiency with variation of pH due to the change in the distance between fluorophore and AuNP. This AuNP‐based pH sensor exhibits a well‐defined on‐and‐off behavior at a small change in pH, and therefore can be used for an ideal alarm‐type sensor.
