Highly Sensitive Colorimetric Naked-Eye Detection of Hg^II Using a Sacrificial Metal–Organic Framework

Abstract

This study has developed a specific, easy, and novel approach to designing a sacrificial metal–organic framework (MOF) that can detect and measure the amount of Hg2+ in aqueous and nonaqueous solutions using the naked eye. The functionalized [Zn­(oba)­(RL3)0.5] n ·1.5DMF (TMU-59) provides the ability of simple visual assessment or colorimetric readout without sophisticated analytical equipment. Because of the special interaction with Hg2+, degradation of the structure of this unique MOF causes the solution to change color from colorless to a pink that is easily recognizable to the naked eye. The presence of a methyl group plays a major role in naked-eye detection by a qualitative sensor. Furthermore, this qualitative sensor data for the production of a simple, instant, and portable red, green, and blue (RGB)-based quantitative sensor were used to determine the concentration of Hg2+ in different specimens. As a turn-off fluorescence sensor, this unique structure is also capable of detecting Hg2+ at very low concentrations (the limit of detection is 0.16 ppb). To the best of our knowledge, TMU-59 is the first MOF-based naked-eye sensor that can successfully and specifically display the presence of Hg2+ through a major color change.

Drug Delivery Using Hydrophilic Metal–Organic Frameworks (MOFs): Effect of Structure Properties of MOFs on Biological Behavior of Carriers

“…TMU-6­(RL1) and TMU-21­(RL2) were previously synthesized. , The RL1 and RL2 ligands, H 2 OBA and Zn­(NO 3 ) 2 ·6H 2 O, were used to synthesize TMU-6­(RL1) and TMU-21­(RL2) under solvothermal conditions (Figure ). TMU-6­(RL1): FT-IR (KBr pellet) selected bands 653 (m), 775 (m), 876 (m), 1015 (m), 1086 (m), 1158 (s), 1231 (vs), 1403 (vs), 1511 (m), 1607 (vs), 1680 (m), 2855 (s), 2923 (w), and 3371 (w) cm –1 .…”

A water stable and highly fluorescent Zn(ii) based metal–organic framework for fast detection of Hg2+, CrVI, and antibiotics

“…Even at low concentrations, these two ions cannot be excreted through biodegradation and are likely to be enriched in the human body, which eventually causes a range of diseases such as kidney failure, central nervous system diseases, lung cancer, and so on. [17][18][19][20] and CrO 4 2− ions in water is essential for environmental protection and human health. [21][22][23][24][25][26][27][28][29] Similarly, as the main effective drugs, antibiotics are widely used as bacteriostatic agents in human therapy and animal husbandry.…”

Promising instrument-free detections of various analytes using smartphones with Spotxel® Reader

“…On the other hand, the smartphone can photograph this optical signal change, and then use appropriate software to transmit the specific value of the signal, and calculate the concentration of the target [ 18 , 19 ]. To achieve low-cost analysis, optical signal analysis software including Color picker [ 20 – 22 ], ImageJ [ 23 – 25 ], Matlab [ 21 , 26 – 28 ], etc., have been used for the determination of different analytes in combination with a smartphone. For instance, the Color picker can convert an image obtained from a smartphone to RGB information.…”