In-situ synthesis of fluorescent gold nanoclusters with electrospun fibrous membrane and application on Hg (II) sensing

In the present study, a method for in-situ preparation of fluorescent gold nanoclusters with bovine serum albumin/poly(ethylene oxide) electrospun membrane (BSA/PEO-Au NCs) has been developed to detect Hg2+. In this work, Au NCs were immobilized both inside and on the surface of fibrous membrane using one-step reduction of HAuCl4 by BSA. The as-prepared BSA/PEO-Au NCs were able to emit intensive red fluorescence under the excitation of visible light, and the fluorescence could be quenched by Hg2+. The results indicate that the as-prepared BSA/PEO-Au NCs exhibit good sensitivity towards Hg2+, which might be benefit from the large specific surface area of BSA/PEO fibrous membrane. The biosensor exhibits a linear response to Hg2+ concentrations ranging from 0.5nM to 75nM with a limit of detection (LOD) of 57pM. Moreover, BSA/PEO-Au NCs shows good selectivity towards other common metal ions. With the advantages of the simple preparation process and good detection performance, the proposed method is anticipated to fabricate other sensitive fluorescence fiber-based sensors of metal nanoclusters. ► A method for in-situ preparation of fluorescent gold nanoclusters with fibers. ► We combine nanoclusters with electrospinning technology to get larger surface areas. ► The water-solubility of fibers changed after aging process. ► This sensor is capable to detect Hg(II) with high sensitivity and good selectivity. ► The limit of detection for Hg(II) was 57pM.