A Thermo-Responsive Colorimetric Sensor based on ChromoProbe−Polymeric Nanocomposite: A Strategic Tool for Visual UranylRecognition in Water

This paper presents the synthesis of a thermo-responsive colorimetric sensor based on aninorganic-organic hybrid nanocomposite for the naked-eye detection of uranyl ions from anaqueous solution. The constructed composite is based on modified TiO2 NPs composed of polyN-isopropyl acrylamide (PNIPAM) as thermoresponsive moieties, vinylated fluoresceinhydrazineas chromo probe compound, and N,N'-methylenebisacrylamide as a cross-linkeragent. The successfully synthesized of chemosensor was characterized by FT-IR, NMR, SEM,TEM, DLS, EDS and EDAX-Mapping. This membrane is capable to determine UO22+ over awide linear dynamic range from 1 ppb to 1000 ppm at optimum condition with detection limitsof 1 ppb and a response time of 10 s. The adsorption and colorimetric detection of uranyl ionsincreased with increasing pH and temperature and reached a maximum value at pH=6.0 and38 ºC. The proposed mechanism of naked-eye detection of uranyl ions was investigated byapplying dual temperature conditions. The selectivity characteristic of chemosensor wasstudied in the presence of various interface ions and the results showed a strong affinity towarduranyl ions. As a result, the novel colorimetric sensor was introduced with features such as afast, selective, sensitive and inexpensive screening test for recognizing uranyl ionscontamination in water samples.

A Thermo-Responsive Colorimetric Sensor based on ChromoProbe−Polymeric Nanocomposite: A Strategic Tool for Visual UranylRecognition in Water Keywords:

Thermoresponsive Polymers , Green Chemistry , Uranium (VI) , ColorimetricSensor , Environmental Monitoring