Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

An all-fiber system biosensor for trace β-lactam antibiotics detection enhanced by functionalized microfiber and fiber bragg grating

An all-fiber-optic system for rapid detection of antibiotic concentration, based on an optical enzyme biosensor with microfiber interferometer (MFI) and fiber gratings (FBGs) power variation, is proposed and experimentally validated. During the experiment, β-lactamase(β-LS) is fixed on the polyaniline (PANI)-coated optical fiber by cross-linking through glutaraldehyde (GA) covalent bonding. β-LS can hydrolyze β-lactam antibiotics to generate acidic by-products that transform polyaniline from the form of the emerald base to emerald salt, which results in the surface refractive index (RI) variation of MFI, to convert MFI wavelength and FBGs power macroscopic change for feedbackingly detecting the concentration of β-lactam antibiotics. The detection of amoxicillin (AMX) in deionized water at concentrations in the range of 0.01-100 nM resulted in a wavelength change sensitivity of 0.6 nm/nM, and FBGs power difference change sensitivity of 1.3 dB/nM, with a detection limit LOD = 0.04 nM in real food and urine samples. The sensing system by the same calibration technique can detect antibiotic concentrations in different substances (tap water, milk and artificial urine). This developed all-fiber-optic system can be used as a rapid solution for the measurement of β-lactam antibiotic residues in food and the environment.

Two Stable Bifunctional Zinc Metal-Organic Frameworks with Luminescence Detection of Antibiotics and Proton Conduction

Functionalized crystalline solids based on metal-organic frameworks (MOFs) enable efficient luminescence detection and high proton conductivity, making them crucial in the realms of environmental monitoring and clean energy. Here, two structurally and functionally distinct zinc-based MOFs, [Zn(TTDPa)(bodca)]·H2O (1) and [Zn(TTDPb)(bodca)]·H2O (2), were successfully designed and synthesized using 3,6-di(pyridin-4-yl)thieno[3,2-b]thiophene (TTDPa) and 2,5-di(pyridin-4-yl)thieno[3,2-b]thiophene (TTDPb) as ligands, in the presence of bicyclo[2.2.2]octane-1,4-dicarboxylic acid (H2bodca). Both 1 and 2 display a three-dimensional (3D) structure with 5-fold interpenetration, and notably, 2 forms a larger one-dimensional pore measuring 17.16 × 10.81 Å2 in size. Fluorescence experiments demonstrate that 1 and 2 can function as luminescent sensors for nitrofurantoin (NFT) and nitrofurazone (NFZ) with low detection limits, remarkable selectivity, and good recyclability. A comprehensive analysis was conducted to investigate the differing sensing effects of compounds 1 and 2 and to explore potential sensing mechanisms. Additionally, at 328 K and 98% relative humidity, 1 and 2 exhibit proton conductivity values of 2.13 × 10-3 and 4.91 × 10-3 S cm-1, respectively, making them suitable proton-conducting materials. Hence, the integration of luminescent sensing and proton conductivity in monophasic 3D Zn-MOFs holds significant potential for application in intelligent multitasking devices.

Fabrication of an electrochemical sensor based on eggshell waste recycling for the voltammetric simultaneous detection of the antibiotics ofloxacin and ciprofloxacin

In this work, an accurate, highly sensitive, and economical electrochemical sensor based on a carbon paste electrode modified by Ca2CuO3 nanostructure (Ca2CuO3 NS) was constructed using Eggshell waste recycling as a cheap source of calcium. The Ca2CuO3 NS was analyzed using FTIR, SEM, and XRD measurements. The synthesized nanomaterials utilized for the first time to enhance the electrocatalytic efficiency of carbon paste electrode (CPE) toward fluoroquinolones antibiotics ofloxacin (OFL) and ciprofloxacin (CIP), The drugs used to treat pneumonia caused by COVID-19. The synthesized Ca2CuO3 NS dramatically enhanced the anodic peak response of CPE toward both drugs compared to the unmodified one and other modified electrodes. The simultaneous detection of the two antibiotics was performed in the linear range of 0.09-1.0 μM for OFL and 0.05-0.8 μM for CIP with the LOD of 0.027 μM and 0.012 μM, respectively. The suggested method was applied successfully to determine OFL and CIP in real samples.