Highly Sensitive Optical Sensor for Selective Detection of Fluoride Level in Drinking Water: Methodology to Fabrication of Prototype Device

Abstract

Excess consumption of fluoride through drinking water and its detrimental effects on human health have been a serious global concern. Therefore, frequent monitoring as well as quantitative determination of fluoride ion (F -) concentration in aqueous media is of vital importance. Herein, we have developed a facile and highly sensitive spectroscopic technique for selective detection of Fin aqueous media using aluminium phthalocyanine chloride (AlPc-Cl) as a sensor. The absorbance as well as steady-state fluorescence intensity of AlPc-Cl has been found to decrease in presence of Fwhich has been used as a marker for the determination of fluoride ion concentration in water. The structural change in AlPc-Cl after addition of Fhas been thoroughly studied by using 19 F NMR (Nuclear Magnetic Resonance) spectroscopy. Our detailed steady-state as well as time-resolved fluorescence studies reveal that the quenching mechanism is static in nature due to ground state complexation in between Fand AlPc-Cl molecules. The response of the sensor is found to be linear over the Fconcentration regime from 0 to 6 parts per million (ppm) with a detection limit of 0.05 ppm. Additionally, it shows an excellent selectivity as well as an insignificant change in sensitivity even in the presence of interfering iron and aluminium ions. Based on the detailed photophysical study, we have further developed a low cost and portable prototype device which shows an excellent sensitivity with the detection limit of 0.10 ppm. This prototype device has a high prospect for real-time monitoring of fluoride ion concentration especially in remote areas.

Laser‐Patterned Carbon‐Supported Graphitic Carbon Nitride Quantum Dots for Flexible Nanozyme‐Based Fluoride Sensor

“…This can be achieved by implementing cost-efficient, portable, and reliable sensors capable of selectively detecting fluoride ions in water, even in minute concentrations. [29] Although a lot of sensing methods have been exploited for quantitative and qualitative assessment of fluoride levels in drinking water, [30][31][32][33][34][35] their real-time usage remains a challenge due to the requirement of trained personnel as well as expensive instrumentation. Nanozyme-based sensing of fluoride in water provides the advantage of naked-eye detection, in the form of color change.…”

Nanoarchitectonics and Kinetics Insights into Fluoride Removal from Drinking Water Using Magnetic Tea Biochar

“…A low fluoride level (<0.5 mg/L) helps to treat dental decay and osteoporosis in the human body. Therefore, it is allowed to be added into drinking water, pharmaceutical agents, and toothpastes [ 3 ]. In contrast, a high concentration of fluoride (>1.5 mg/L) causes several health problems, such as skeletal and dental fluorosis, sweating, restlessness, and joint deformation [ 4 ].…”

“…In contrast, a high concentration of fluoride (>1.5 mg/L) causes several health problems, such as skeletal and dental fluorosis, sweating, restlessness, and joint deformation [ 4 ]. A high fluoride concentration also causes neurotoxicity in children, which results in lower IQ (intelligent quotient) levels [ 3 ]. Excessive fluoride in drinking water is due to the combination of anthropogenic activities, weathering of fluorine minerals, and industrial activities [ 5 ].…”

“…Small size, high charge density, capabilty of forming H-bonding, and strong basic nature makes its detection tedious [ 11 ]. Varios methods, such as electrochemical [ 3 ], spectroscopic [ 12 ] and fluorescent sensors [ 13 ], and chemosensors [ 14 ], are used for fluoride detection. Excessive fluoride concentration in drinking water is an important environmental problem worldwide, due to its negative and toxic effects [ 5 ].…”

Fluoride-philic reduced graphene oxide–fluorophore anion sensors

“…The permissible dose of tolerance of F − ions in drinking water is 1.5 parts per million (ppm), ∼78.9 μM, as per WHO guidelines. Various methods, including optical, 11 chemodosimetric, 12 and electroanalytical, 13 have been widely investigated.…”