Introduction

2-Aminoterephthalic acid (Figure 1) is an organic compound with the molecular formula of C₈H₇NO₄. It is an organic chemical intermediate. Herein its application research will be introduced.

2-Aminoterephthalic acid as a cross-linking agent

Metal halide perovskite solar cells (PSCs), with their exceptional properties, show promise as photoelectric converters. However, defects in the perovskite layer, particularly at the grain boundaries (GBs), seriously restrict the performance and stability of PSCs. In this study, researchers introduce efficient and stable PSCs by using 2-aminoterephthalic acid as a cross-linking agent to modify the exposed GBs. The organic compound contained a benzene ring, an ammonium group (-NH₂), and two carboxyl groups (-COOH). The molecules could easily assemble at the GBs because the benzene ring had a high cohesive energy due to its robust structure and the strong interaction of its π-π bonds. Owing to the existence of a benzene ring, it was also facile to form a hydrophobic passivating layer that prevented the permeation of moisture along the GBs. The -NH₂ and -COOH groups interacted with Pb and/or I ions in perovskite, which inhibited the migration of ions and passivated the trap states at the GBs derived from the under-coordinated Pb and I ions. After a passivating treatment with the appropriate 2-aminoterephthalic acid concentration, the PCE improved from 19.13% for the control device to 21.09% for the cross-linked device.Additionally, the cross-linked device exhibited a smaller hysteresis and improved stability against moisture and oxygen. Most importantly, a sufficient experimental characterization was achieved, which proved that the defect passivation occurred at the GBs. These investigation provides a potential strategy for creating efficient and stable PSCs and for the passivation of GBs.[1]

The amine functionalization with 2-aminoterephthalic acid

A screen-printed electrode prepared from graphene oxide (GO) has been functionalized with 2-aminoterephthalic acid, followed by the exploitation of this functional material in an electrochemical immunoassay for Escherichia coli (E. coli) by immobilizing the antibody on its surface. The functionalization steps followed a straightforward approach and were proven by various instrumental techniques. The detection of E. coli with antibody immobilized electrodes was performed using electrochemical impedance spectroscopy. The analyses were carried out using the hexacyanoferrate redox couple as the electrochemical probe. The present method has a wide analytical range (from 2.2?×?10² to 2.2?×?10⁸ cfu/mL), a low limit of detection (2 cfu/mL), fast response (4 min), and good stability (up to 2 months). The analytical performance of the biosensor was comparable to the previously reported electrochemical biosensors for E. coli. As such, the approach of functionalization of graphene with 2-aminoterephthalic acid should be useful to allow the development of other similar sensing systems for other environmentally and clinically important analytes.[2]

2-Aminoterephthalic Acid-Derived Pigments

In this study, researchers developed a simple and economical method for the green synthesis of Cu2+ sensors based on betaxanthin pigments. Aminoisophthalic acid-betaxanthin was synthesized by coupling 2-aminoisophthalic acid and betalamic acid produced from DOPA-extradiol-4,5-dioxygenase in situ and in vitro. The resulting 2-aminoterephthalic acid-betaxanthin (2-AIPA-BX) presented a satisfying fluorescence quantum yield in water and a high degree of selectivity for Cu²⁺ over interfering metal ions. The bioproduction process of 2-AIPA-BX was scaled up from test tubes to 1 L-flasks, indicating the robustness and reproducibility of this method. Additionally, they successfully incorporated 2-AIPA-BX into paper-based analytical devices to facilitate simple, inexpensive, and portable setup with lower sample consumption for onsite monitoring of environmental and biological samples.[3]

2-Aminoterephthalic acid as organic linker

In this work, a fluorescent sensor based on a zirconium-based metal organic framework was prepared for the detection of tetracyclines (TCs) in milk. The UiO-66-NH₂ fluorescent sensor was synthesized bya simple microwave-assisted method with 2-aminoterephthalic acid and zirconium chloride as precursors.The UiO-66-NH₂, synthesized through utilizing Zr⁴⁺ as metal centre and 2-aminoterephthalic acid(ATA) as organic linker, contained abundant –NH₂ on its surface, which increased its stability in water and provided a binding site for target TCs. The as-prepared UiO-66-NH2 possessed good fluorescence performance, and could be quenched by TCs because of photo-induced electron transfer(PET) (the electron transfer from 2-aminoterephthalic acid organic ligand to TCs) and inner filter effect (IFE). Moreover, the hydrogen bond interaction between amino groups on UiO-66-NH₂ and hydroxyl groupsof TCs enabled the fluorescence sensor to detect TCs specifically from a series of interference factors (antibiotics, ions and amino acids). The proposed UiO-66-NH₂ sensor had good sensitivity and selectivity, and under the optimal conditions possessed detection limits of 0.449, 0.431, and 0.163 mM for tetracycline (TET), oxytetracycline (OTC),and doxycycline (DOX), respectively. Besides, the UiO-66-NH₂ sensor was successfully applied to the quantitative detection of TCs in milk samples with reasonable recoveries of 93.26-115.17%, and the detection results achieved from the as-fabricated fluorescence sensing assay were consistent with those of high-performance liquid chromatography (HPLC), indicating the potential applicability of the UiO-66-NH2 sensor for detecting TCs in actual food samples.Eventually, due to high sensitivity and excellent selectivity, the established fluorescence sensing analysis method was successfully applied to detect TCs in actual milk samples with desirable results.[4]

References

[1] Liu Z, Cao F, Wang M, Wang M, Li L. Observing Defect Passivation of the Grain Boundary with 2-Aminoterephthalic Acid for Efficient and Stable Perovskite Solar Cells. Angew Chem Int Ed Engl. 2020;59(10):4161-4167. doi:10.1002/anie.201915422

[2] Gupta A, Bhardwaj SK, Sharma AL, Deep A. A graphene electrode functionalized with aminoterephthalic acid for impedimetric immunosensing of Escherichia coli. Mikrochim Acta. 2019;186(12):800. Published 2019 Nov 18. doi:10.1007/s00604-019-3952-1

[3] Shih CI, Chou YC, Chen HY, Chen KH, Wang IH, Yeh YC. Colorimetric and Fluorometric Paper-Based Assay for Cu2+ Detection Based on Green Synthesis of 2-Aminoterephthalic Acid-Derived Pigments. ACS Appl Bio Mater. 2020;3(4):2516-2521. doi:10.1021/acsabm.0c00212

[4] Wang X, Wang X. UiO-66-NH2 based fluorescent sensing for detection of tetracyclines in milk. RSC Adv. 2022;12(36):23427-23436. Published 2022 Aug 17. doi:10.1039/d2ra04023a