Highly-Efficient Sulfonated UiO-66(Zr) Optical Fiber for Rapid Detection of Trace Levels of Pb2+

Abstract

Lead detection for biological environments, aqueous resources, and medicinal compounds, rely mainly on either utilizing bulky lab equipment such as ICP-OES or ready-made sensors, which are based on colorimetry with some limitations including selectivity and low interference. Remote, rapid and efficient detection of heavy metals in aqueous solutions at ppm and sub-ppm levels have faced significant challenges that requires novel compounds with such ability. Here, a UiO-66(Zr) metal-organic framework (MOF) functionalized with SO3H group (SO3H-UiO-66(Zr)) is deposited on the end-face of an optical fiber to detect lead cations (Pb2+) in water at 25.2, 43.5 and 64.0 ppm levels. The SO3H-UiO-66(Zr) system provides a Fabry–Perot sensor by which the lead ions are detected rapidly (milliseconds) at 25.2 ppm aqueous solution reflecting in the wavelength shifts in interference spectrum. The proposed removal mechanism is based on the adsorption of [Pb(OH2)6]2+ in water on SO3H-UiO-66(Zr) due to a strong affinity between functionalized MOF and lead. This is the first work that advances a multi-purpose optical fiber-coated functional MOF as an on-site remote chemical sensor for rapid detection of lead cations at extremely low concentrations in an aqueous system.

Sulfonated Metal–Organic Framework Mixed-Matrix Membrane toward Direct Lithium Extraction

“…Briefly, the MOF precursor mixture was heated at 120 °C for 3 d and then extensively washed in DMF and methanol and then evacuated under reduced pressure (see Experimental in Supporting Information). This UiO-66-SO 3 H work demonstrates permanent microporosity with pores of 6.3 and 9.5 Å, and a similar Brunauer–Emmett–Teller (BET) surface area of 392 m 2 /g compared to previous reports of 491 m 2 /g, collapsing upon activation, or 550 m 2 /g. − The UiO-66-SO 3 H gave a particle size distribution of 312 ± 69 nm, compared to the UiO-66 distribution of 296 ± 40 nm as measured by an SEM survey image. After characterization showed that the MOF retained desirable factors of crystallinity, SO 3 H groups, and pore sizes under 1 nm (Figures S3 and S4, Supporting Information), the activated MOF was added to a CTA/DCM solution, stirred, sonicated, and solution cast into a glass dish.…”

Recent Progress in Metal-Organic Framework Based Fluorescent Sensors for Hazardous Materials Detection

“…At the same time, when the content of Pb 2+ ions is at quite a low level, a perfect linear relationship between fluorescence quenching efficiency and concentration was illustrated. When compared with other MOFs, the Zn-TCPP-MOF detected Pb 2+ ions in water, at very low concentrations, as well as at its fully lower limit of detection (LOD) of 4.99 × 10 − 8 M. The SO 3 H-UiO-66(Zr) MOF system, functionalized with an SO 3 H group and usually installed in the end-face of an optical fiber, implemented the function of detecting Pb 2+ in water at 25.2, 43.5, and 64.0 ppm levels [ 74 ]. The proposed removal mechanism is based on the adsorption of [Pb(OH 2 ) 6 ] 2+ in water on SO 3 H-UiO66(Zr) because of a strong affinity between functionalized MOF and lead, as shown in Figure 9 .…”

Optical fiber sensors for water and air quality monitoring: a review

“…The sensor exhibited a Pb 2þ sensitivity of 1.2 nm∕μg∕L, and the lower limit of detection was 0.001 ppm. Nazari et al 82 developed an efficient sulfonated UiO-66(Zr) optical fiber for the rapid Pb 2þ detection. UiO-66(Zr) metal-organic frameworks (MOFs) functionalized with SO 3 H groups ½SO 3 H-UiO-66ðZrÞ was modified on the end face of the optical fiber to detect lead cations in water at 25.2, 43.5, and 64.0 ppm levels.…”

“…The sensor exhibited a Pb2+ sensitivity of 1.2 nm/μg/L, and the lower limit of detection was 0.001 ppm. Nazari et al 82 . developed an efficient sulfonated UiO-66(Zr) optical fiber for the rapid Pb2+ detection.…”