2026-07-24T16:37:44Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/110652025-11-15T01:05:35Zcom_10259_5822com_10259_5086com_10259_2604col_10259_5823

00925njm 22002777a 4500 dc Ruiz Fernández, Virginia author Pérez-Marquez, Ana author Maudes, Jon author Grande, Hans J. author Murillo, Nieves author 2018-06 We report a method to encapsulate graphene quantum dots (GQD) in polyacrylonitrile (PAN) nanofibrous membranes to manufacture robust filtering membranes by electrospinning. GQD-PAN membranes with different nanofiber diameter were prepared tuning the electrospinning parameters, all exhibiting the characteristic fluorescence fingerprint of the GQD probes. The photoluminescence (PL) stability of GQD embedded in the PAN fibers was significantly enhanced with respect to that of water dispersed GQD luminescent probes. The PL of GQD-PAN filtering membranes showed remarkable time stability, both stored dry and immersed in phosphate buffer solutions (PBS), as well as exposed to continuous light irradiation. However, the PL intensity of GQD-PAN membranes was irreversibly quenched by highly oxidant free chlorine solutions. Thus, electrospun GQD-PAN membranes exhibited excellent performance as turn-off fluorescence sensing platforms for free chlorine detection in PBS 0.1 M pH 7. The analytical performance of GQD-PAN membranes was comparable to that of GQD solutions with optimal concentrations, displaying a fast (no need of incubation time) and linear response to chlorine concentration in the 10–600 μM range, a low detection limit of 2 μM, high sensitivity, reproducibility and selectivity. Moreover, the sensing performance of the membranes was very stable after being immersed in PBS for months, outperforming the stability of GQD solutions. 0925-4005 https://hdl.handle.net/10259/11065 10.1016/j.snb.2018.02.081 Graphene quantum dots Nanofibers Membranes Electrospinning Fluorescence sensor Chlorine detection Enhanced photostability and sensing performance of graphene quantum dots encapsulated in electrospun polyacrylonitrile nanofibrous filtering membranes