Flexible and highly stable electrospun nanofibrous membrane incorporating gold nanoclusters as an efficient probe for visual colorimetric detection of Hg(ii)

Abstract

Here, we describe the visual colorimetric detection of Hg2+ based on a flexible fluorescent electrospun nanofibrous membrane (NFM). It is an efficient approach, in which we have effectively integrated fluorescent gold nanoclusters (AuNC) into electrospun polyvinyl alcohol nanofibers. Interestingly, the resulting composite nanofibers (AuNC*NFM) are shown to retain the fluorescence properties of AuNC and exhibit red fluorescence under UV light, being cogent criteria for the production of a visual colorimetric sensor. Furthermore, capabilities with regard to the stability of the AuNC*NFM have been under observation for a period of six months, with conditions matching those of typical atmosphere, and the resulting outcome has thrown light on their long-term storability and usability. It is clear, from the fact that the nanofibrous membrane preserves the fluorescence ability up to a temperature of 100 °C, that temperature does not have an effect on the sensing performance in real-time application. The water-insoluble AuNC*NFM have been successfully tailored by cross-linking with glutaraldehyde vapor. Further, the contact mode approach has been taken into consideration for the visual fluorescent response to Hg2+, and the observed change of color indicates the utility of the composite nanofibers for onsite detection of Hg2+ with a detection limit of 1 ppb. The selectivity of the AuNC*NFM hybrid system has been analyzed by its response to other common toxic metal interferences (Pb2+, Mn2+, Cu2+, Ni2+, Zn2+, Cd2+) in water. Several unique features of the hybrid system have been determined, including high stability, self-standing ability, naked-eye detection, selectivity, reproducibility and easy handling-setting a new trend in membrane-based sensor systems. © 2014 the Partner Organisations

Chemical etching of bovine serum albumin-protected Au25 nanoclusters for label-free and separation-free detection of cysteamine

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Highly responsive glutathione functionalized green AuNP probe for precise colorimetric detection of Cd2+ contamination in the environment

“…As gold nanoparticles (AuNPs) have emerged as a promising colorimetric probe that supports naked-eye-based readout methods, even at nanomolar concentrations that show observable red-to-blue color change upon nanoparticle aggregation due to their high extinction coefficient [40][41][42] there is a need for "green chemistry" that includes a clean, nontoxic, and environment-friendly method of gold nanoparticles synthesis. There are many reports on using chemically synthesized AuNPs as colorimetric sensors for heavy metal detection, some of which are listed in synoptic Table S1 [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] . From the synoptic table it is worth mentioning that there are not many reports on using AuNPs synthesized using plant extract as colorimetric sensor for heavy metal detection.…”

Constitution of a visual detection system for lead(ii) on polydiacetylene–glycine embedded nanofibrous membranes

“…[40][41][42] The performance of the matrix is optimized based on the following four decisive criteria: (1) good homogeneity of PDA in the nanobers, (2) stability against time, (3) hydrophilic nature in water, and (4) high specic surface area (SSA) and porosity. [40][41][42] The performance of the matrix is optimized based on the following four decisive criteria: (1) good homogeneity of PDA in the nanobers, (2) stability against time, (3) hydrophilic nature in water, and (4) high specic surface area (SSA) and porosity.…”