Sensing Heavy Metals Using Mesoporous‐Based Optical Chemical Sensors

Abstract

Heavy metal pollution is one of the more serious environmental problems; therefore, there is a constant demand for the development of new analytical tools for its monitoring. An optical chemical sensor represents a good alternative to classical instrumental methods. The mesoporous materials used in optical chemical sensors' fabrications have properties such as high porosity, exceptional adsorption capacity, tuneable 3D shape, geometry, and morphology, which enable improved limit of detection, response time, and selectivity properties of optical sensors. In this review, we firstly present the properties of mesoporous materials, provide a brief description of sensing mechanisms, and briefly discuss the importance of continuous monitoring. Recent advances in those mesoporous silica-based optical sensors used for heavy metal detection have been reported and their advantages and limitations also discussed. This review covers publications that have appeared since 2008.

Activated alumina preparation and characterization: The review on recent advancement

“…Eliassi and Ranjbar 2014 [25][26][27][28][29][30][31][32][33][34][35][36] proposed the impurities removal to remove the impurities by washing and then centrifuging rather than using filter paper Fig. 3 shows the gamma alumina calcinated in 500, (a) SEM image for Nano gamma alumina produced by calcinations in 550°C and (b) the XRD Nano gamma alumina produced by calcinations in 550°C [37][38][39][40].…”

“…With controlled Sol-gel process parameters, these include time gel time, pH, and temperature and hydrolysis ratio. Bussarin and his team were able to monitor the sol-gel transition of alcoholic alumatrane solution via multiple waveform rheological measurements to characterize the materials [37][38][39][40].…”

Organically Functionalized Mesoporous SBA-15 Type Material Bearing Fluorescent Sites for Selective Detection of HgII from Aqueous Medium

“…So, it becomes an obvious challenge that sensor probes are designed in such a way so that they can be applied in water with good efficacy to detect toxic and poisonous metals in the presence of other nonharmful metal ions. 21,22…”

Fluorescent and Colorimetric Electrospun Nanofibers for Heavy-Metal Sensing

“…Absorption or colorimetric sensing is accomplished using an indicator that changes its color upon binding to the analyte; this change is not only spectroscopically determined but can also be visible. In light-emission methods, the analyte concentration is determined by the change in the emission properties of a fluorophore after being excited by a defined wavelength [ 23 ]. Therefore, this paper reviews the recent progress on the development of ESNF-based optical sensors using colorimetric or fluorescent methods for the determination of heavy metals.…”