Highly sensitive yet cheaper sensor to detect mercury in water – thanks to nanofibers



Mercury is one of the dangerous pollutants present in the environment. Mercury contamination in drinking water leads to various diseases includes digestive, heart, kidney and neurological disorders. It is therefore important to detect mercury levels in water as a potential source of contamination.

Optical sensors are widely preferred for quantifying mercury in water because they offer potential advantages over conventional electrochemical methods such as electrical isolation, reduced noise interference, and the possibility of miniaturisation. Optical sensors have the detection limit of 1.6 ng mL−1, and with incorporation of nanoparticle, the detection limit reached nearly 0.52 ng mL−1. Despite the sensitivity, current optical sensors face several constraints; for example, the fluorescence-based sensors though a sensitive technique for mercury it is a complex and expensive system from an industrial point of view. As the operating temperature is high (~40 °C), the easy applicability to real samples are restricted.

To solve these inconveniences, scientists led by Prof. Fernández-Sánchez from University of Granada- Spain and University of Extremadura-Spain in collaboration with NanoMyP, a spin-off company developed highly sensitive optical sensors by immobilizing the chemodosimeter into polymer microfibrous nonwoven mats that are produced by electrospinning. Such immobilization facilitated the chemodosimeter to preserve its sensing ability, displayed intense turn-on fluorescence in the presence of mercury. The electrospun fibre mat helped the optical sensor to reach the much better detection limit of 0.1 μM Hg2+,which is about 2.6 times better than those of the same chemodosimeter attached into a classical polymeric sensing film.

The team highlighted that the excellent mechanical strength, high consistency and high flexibility, and large surface area resulted from electrospinning process complimented the successful fabrication of optical sensors and also reduced the cost of the analysis. In addition, the fibre mat was highly hydrophilic but insoluble in both aqueous media and in nonpolar solvents.

The team concluded that as-developed electrospun fibre mat increased the sensitivity and decreased the response time to determine Hg2+ and also met the discharge limit for industrial wastewater according to the U.S. EPA standard and the China SA standard.

The post was originally posted by Nafigate at http://www.nafigate.com/en/section/portal/app/news/detail/70450-highly-sensitive-yet-cheaper-sensor-to-detect-mercury-in-water-thanks-to-nanofibers