A hydrophilic fluorescent polymer containing naphthalimide moiety as chemosensor for microbioreactors

A novel hydrophilic copolymer P(NI-HEMA) containing the pendant group of naphthalimide moiety has been prepared. In the aqueous buffer solution, its film on the glass substrate shows an obvious fluorescence change and excellent linear relevance in the pH range of 5.8-8.0. Specifically, using the isobestic point at 406 nm as excitation wavelength can avoid the UV irradiation and the tedious calibration process. The film stability and hydrophilicity of copolymer P(NI-HEMA) were studied. Because of the easy synthesis, low price and high linear relevance to pH, the hydrophilic chemosensor film of P(NI-HEMA) could be potentially applied as a low-cost pH indicator for high-throughput bioprocessing in microreactors.