12 research outputs found
Advances on ultra-sensitive electrospun nanostructured electrochemical and colorimetric sensors for diabetes mellitus detection
Functionalized Electrospun Nanofibers as Colorimetric Sensory Probe for Mercury Detection: A Review
Mercury is considered the most hazardous pollutant of aquatic resources; it exerts numerous adverse effects on environmental and human health. To date, significant progress has been made in employing a variety of nanomaterials for the colorimetric detection of mercury ions. Electrospun nanofibers exhibit several beneficial features, including a large surface area, porous nature, and easy functionalization; thus, providing several opportunities to encapsulate a variety of functional materials for sensing applications with enhanced sensitivity and selectivity, and a fast response. In this review, several examples of electrospun nanofiber-based sensing platforms devised by utilizing the two foremost approaches, namely, direct incorporation and surface decoration envisioned for detection of mercury ions are provided. We believe these examples provide sufficient evidence for the potential use and progress of electrospun nanofibers toward colorimetric sensing of mercury ions. Furthermore, the summary of the review is focused on providing an insight into the future directions of designing electrospun nanofiber-based, metal ion colorimetric sensors for practical applications
Single nozzle electrospinning promoted hierarchical shell wall structured zinc oxide hollow tubes for water remediation
Functionalized Electrospun Nanofibers as Colorimetric Sensory Probe for Mercury Detection: A Review
Paper sensors based on fluorescence changes of carbon nanodots for optical detection of nanomaterials
This article belongs to the Special Issue Sustainable Development of Nanotechnologies: Risks and Opportunities for Occupational Safety and Health.A paper sensor was designed in order to detect the presence of nanomaterials, such as ZnO and silica nanoparticles, as well as graphene nanoplatelets (GnP), based on fluorescence changes of carbon nanodots. Paper strips were functionalized with carbon nanodots using polyvinyl alcohol (PVA) as binder. The carbon nanodots were highly fluorescent and, hence, rendered the (cellulosic) paper stripes emissive. In the presence of silica and ZnO nanoparticles, the fluorescence emission of the carbon nanodots was quenched and the emission decay was shortened, whereas in the presence of GnP only emission quenching occurred. These different photoluminescence (PL) quenching mechanisms, which are evident from lifetime measurements, convey selectivity to the sensor. The change in fluorescence of the carbon dot-functionalized paper is also evident to the naked eye under illumination with a UV lamp, which enables easy detection of the nanomaterials. The sensor was able to detect the nanomaterials upon direct contact, either by dipping it in their aqueous dispersions, or by sweeping it over their powders. The use of the proposed optical sensor permits the detection of nanomaterials in a straightforward manner, opening new ways for the development of optical sensors for practical applications.This research was part of the Project âNano and Key enabling technologies within the innovation processes: risk and opportunities in occupational settings by prevention through design (NanoKey__EPTR0003))â, funded by the Italian Workersâ Compensation Authority (INAIL) and coordinated in cooperation between the INAIL Department of Occupational and Environmental Medicine Epidemiology and Hygiene, and the Italian Institute of Technology (IIT).Peer reviewe
Highly Fluorescent Pyrene-Functional Polystyrene Copolymer Nanofibers for Enhanced Sensing Performance of TNT
A pyrene-functional polystyrene copolymer
was prepared via 1,3-dipolar cycloaddition reaction (Sharpless-type
click recation) between azide-functional styrene copolymer and 1-ethynylpyrene.
Subsequently, nanofibers of pyrene-functional polystyrene copolymer
were obtained by using electrospinning technique. The nanofibers thus
obtained, found to preserve their parent fluorescence nature, confirmed
the avoidance of aggregation during fiber formation. The trace detection
of trinitrotoluene (TNT) in water with a detection limit of 5 nM was
demonstrated, which is much lower than the maximum allowable limit
set by the U.S. Environmental Protection Agency. Interestingly, the
sensing performance was found to be selective toward TNT in water,
even in the presence of higher concentrations of toxic metal pollutants
such as Cd<sup>2+</sup>, Co<sup>2+</sup>, Cu<sup>2+</sup>, and Hg<sup>2+</sup>. The enhanced sensing performance was found to be due to
the enlarged contact area and intrinsic nanoporous fiber morphology.
Effortlessly, the visual colorimetric sensing performance can be seen
by naked eye with a color change in a response time of few seconds.
Furthermore, vapor-phase detection of TNT was studied, and the results
are discussed herein. In terms of practical application,
electrospun nanofibrous web of pyrene-functional polystyrene copolymer
has various salient features including flexibility, reproducibility,
and ease of use, and visual outputs increase their value and add to
their advantage