Four Zn(II)-MOFs as Highly Sensitive Chemical Sensor for the Rapid Detection of Tetracycline, o-Nitro Phenol, Cr₂O₇^2– /PO₄^3–, Fe³⁺/Al³⁺ in Water Environment

Abstract

Uncontrolled industrialization not only caused irreparable damage to the surrounding ecological environments, especially water resources, but also seriously threatened human health. How to sensitively detect toxic pollutants in the hydrological system is a prerequisite for protecting human life. The luminescent metal–organic frameworks (LMOFs) have excellent applications in this field. Herein, four Zn-MOFs, namely [Zn3(dpcp)2(1,4′-bmib)2]n (1), {[Zn4(dpcp)2(4,4′-bibp)2(μ2-O)4]·3H2O}n (2), [Zn­(2-ata)­(bidpe)]n (3), and [Zn­(bbibp)­(HCOO)2]n (4) (dpcp = 3-(3,5-dicarboxylphenoxy)-5-carboxylpyridine, 2-ata = 2-aminoterephthalic acid, 1,4′-bmib = 1,4-bis­(2-methylimidazol-1-yl) butane, 4,4′-bibp = 4,4′-bis­(imidazolyl) biphenyl, bbibp = 4,4′-bis­(benzoimidazo-1-ly) biphenyl, bidpe = 4,4′-bis­(lmidazolyl)­diphenyl ether), were synthesized by solvothermal method and characterized by single crystal X-ray diffraction. For tetracycline, o-nitro phenol, Cr2O7 2– and Fe3+, 1–4 have different degrees of fluorescence quenching effect and exhibit good sensitivity and high-selective detection of the above analytes in the presence of multiple interference species (such as antibiotics, amino acids, metal ions and inorganic ions). Additionally, the heat map and principal component analysis plot visually represent the selective detection effect of Fe3+, Cr2O7 2– and tetracycline by 1–4. Besides, 3 can detect PO4 3– and Al3+ independently with high selectivity from homogeneous pollutants through the fluorescence enhancement phenomenon. This work offers insight into exploring the potential applications of zinc-based MOFs in the chemical sensing field.

Series of TM-OFs as a Platform for Efficient Catalysis and Multifunctional Luminescence Sensing

“…The S-V chart of 2 is shown in Figure e; the corresponding K sv value was 3.2 × 10 4 M –1 , and the LOD for sensing Cr 2 O 7 2– was calculated to be 240 ppb (Figure S16). The sensitivity of 2 to recognize Cr 2 O 7 2– was similar to that of other MOFs reported in the literature. ,− After four cyclic experiments for 2 were used to detect Cr 2 O 7 2– , a slight decrease in fluorescence intensity occurred, which may be caused by the loss of MOFs (Figure f). It is seen from the PXRD pattern that the framework of 2 remained stable after the cyclic test (Figure S17).…”

“…The lowest record limit of detection (LOD) of 2 for sensing Fe 3+ was 17 ppb by using the equation 3σ/ k (σ is the standard deviation of 10 blank tests for the fluorescence intensity of 2 , and k is the slope of the linear relationship between fluorescence intensity and concentration) (Figure S16). The high detection sensitivity of 2 for sensing Fe 3+ ions is approximately equivalent to the sensing ability of other MOFs. ,− In addition to the extraordinarily high selectivity, it is worth noting that the probes can realize the naked-eye detection of trace Fe 3+ ions in water. Additionally, the stability or recyclability is an important characteristic for practical applications.…”

Coordination Polymers as a Functional Material for the Selective Molecular Recognition of Nitroaromatics and ipso‐Hydroxylation of Arylboronic Acids

“…The PXRD pattern of the recovered samples are in good agreement with the experimental one, thereby, suggesting that both 1 and 2 maintained their basic structural integrity even after sensing of NACs and quenching of fluorescence is not caused by disintegration of their crystalline framework structures. [71,72] These observations offering good applicability to 1 and 2 towards the detection applications.…”

Metal–Organic Framework-Based Selective Molecular Recognition of Organic Amines and Fixation of CO2 into Cyclic Carbonates

“…The unaltered PXRD patterns of recycled Zn-MOF- 1 and Cd-MOF- 2 demonstrate that the framework structure persisted even after five consecutive cycles of organic amine sensing. The recyclability experiments indicate that Zn-MOF- 1 and Cd-MOF- 2 can be exploited as potential fluorescence sensors for the organic amines in an aqueous solution. , …”