Halonitrophenols (HNPs) are an emerging type of aromatic disinfection byproduct, with detected concentrations of ∼nmol L−1 in source water and drinking water. Currently, there are no standard methods for identifying HNPs, and most of the reported methods are time-consuming and equipment-dependent. A core–shell metal–organic framework (MOF) based electrochemical sensor (Ag/ZIF-8@ZIF-67) capable of detecting 2,6-dichloro-4-nitrophenol (2,6-DCNP) is reported in this study. The electrochemical sensor obtains the concentration of 2,6-DCNP by detecting the peak current passing through the sensor. In this sensor, Ag nanoparticles (AgNPs) play a key role in electrochemical sensing by reducing nitro groups via electron transfer, and porous structure with a large surface area is offered by ZIF-8@ZIF-67. The cyclic voltammetry (CV) response of Ag/ZIF-8@ZIF-67 was found to be approximately 1.75 times and 2.23 times greater than that of Ag/ZIF-8 and Ag/ZIF-67, respectively, suggesting an ideal synergistic effect of the core–shell structures. The Ag/ZIF-8@ZIF-67 sensor exhibited exceptional sensitivity to 2,6-DCNP, exhibiting a broad linear response range (R2 = 0.992) from 240 nmol L−1 to 288 μmol L−1 and a low detection limit of 20 nmol L−1. Furthermore, the sensor exhibited good anti-interference for isomers and common distractors in water, excellent stability and reproducibility, and high recovery in actual water samples. Our reported sensor gives a novel strategy for sensitive, selective, and in situ detection of 2,6-DCNP in practical analysis.
Lan Yang,Lihua Xin,Junzu Shi,Wei Li,Min Tian,Zixia Hu,Ying Peng,Jiang Zheng
Labetalol hydrochloride (LHCl), an α- and β-adrenoreceptor blocker, is widely used for the treatment of hypertension as well as angina pectoris. Previous reports have demonstrated the adverse events during clinical application of LHCl, such as liver injury and acute renal failure. The present study aimed to investigate metabolic activation of LHCl to initiate the elucidation of the mechanisms of its liver toxicity. One glutathione (GSH) conjugate was detected in rat and human primary hepatocytes as well as bile of rats after exposure to LHCl. The GSH conjugate was chemically synthesized and characterized by Q-TOF and 1H NMR. Pretreatment of 2,6-dichloro-4-nitrophenol (DCNP), a broad-spectrum sulfotransferase (SULT) inhibitor, significantly attenuated the formation of the GSH conjugate in LHCl-treated hepatocytes and animals, indicating the participation of SULTs in metabolic activation of LHCl. Moreover, pretreatment with DCNP displayed significant protection against the observed cytotoxicity in rat primary hepatocytes, which suggests a correlation of the bioactivation of LHCl mediated by SULTs with LHCl-induced hepatotoxicity.
A fluorescent BODIPY probe (SO-BOD) conjugated with a 2-salicylaldoxime group via an ethynyl spacer was designed and synthesized for highly sensitive and selective detection of DCNP (a simulant of Tabun). The probe exhibited significant fluorescent quenching in the presence of Et 3 N, and 30-fold fluorescence enhancement was achieved in the presence of DCNP. Integration of experimental and computational methods well illustrated that these fluorescence variations were attributed to the intramolecular photo-induced electron transfer (PET) process. Except for the low limit of detection (34 nM) to DCNP, SO-BOD also showed a rapid response (t 1/2 = 175 s) and high selectivity. Furthermore, naked-eye detection of DCNP was carried out in both the liquid and vapor phases by test strips immobilized with the probe.