Ratiometric fluorescent detection of superoxide anion with polystyrene@nanoscale coordination polymers

Abstract A novel ratio fluorescence sensor for superoxide anion (O 2 − ) detection was developed with suffocated polystyrene nanoparticles (PS-SO 3 H)@terbium (Tb)/guanine (G) nanoscale coordination polymers (PS-SO 3 H@Tb/G NCPs). The abundant sulfonyl of PS-SO 3 H are served as binding points for the spontaneous self-assembly of Tb 3+ and G on the surface of PS-SO 3 H to form PS-SO 3 H@Tb/G NCPs sensor. The formation of PS-SO 3 H@Tb/G NCPs was verified by detailed characterization ( i.e. , scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and fluorescence emission spectroscopy). The obtained senor exhibits the characteristic fluorescence emission of Tb 3+ and PS-SO 3 H. The fluorescence of PS-SO 3 H is slightly weaken as a reference and the fluorescence of Tb 3+ is largely weaken in the presence of O 2 − , resulting in ratiometric fluorescent sensor toward the O 2 − . The ratio of fluorescence density linearly decreases with the increasing of O 2 − concentration in the range of 10.12 nM-6.0 μM with a detection limit as low as 3.4 nM. This ratiometric fluorescent sensor also shows good selectivity toward O 2 − .