Integration of Mesoporous Copper Coordination Polymer in Electrochemical Platform for Detection of Fluoroquinolone Antibiotic in Biological and Food Samples

TL;DR

A new electrochemical sensor using a copper coordination polymer was developed to detect fluoroquinolone antibiotics in biological and food samples, offering high accuracy and sensitivity.

Contribution

The novel contribution is the development of a copper-based coordination polymer sensor for detecting ciprofloxacin in complex matrices like urine and egg samples.

Findings

The sensor showed excellent linearity (R² = 0.992) and recoveries between 78-108% for ciprofloxacin detection.

The detection limits were 0.5 μmol L⁻¹ in synthetic urine and 3.0 μmol L⁻¹ in egg samples.

The sensor demonstrated high sensitivity and accuracy, suitable for real-world food and biological sample monitoring.

Abstract

Antibiotics are indispensable in both human and veterinary
medicine.
However, their extensive and indiscriminate use has raised serious
environmental and public health concerns, particularly regarding the
emergence of antibiotic-resistant bacteria. In this context, continuous
monitoring of broad-spectrum antibiotics, such as fluoroquinolone
class, is essential. This study reports the development of an electrochemical
sensor based on a copper-based coordination polymer, [Cu­(C8H4O4)]
n
/CPE, for
the detection of fluoroquinolone antibiotic (ciprofloxacin, CIP) in
synthetic urine and egg samples. [Cu­(C8H4O4)]
n
was synthesized via a solvothermal
method, employing 1,4-benzenedicarboxylic acid as the organic ligand
and copper salt as the metal source. The material was characterized
by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction
(XRD), scanning electron microscopy with energy dispersive spectroscopy
(SEM-EDS), thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller
(BET) surface area analysis. Electrode modification was optimized
by varying the modifier content, pH solution, and electrochemical
technique. Optimization using differential pulse voltammetry (DPV)
revealed ideal conditions at pH 6.0 with 20% (w/w) [Cu­(C8H4O4)]
n
. Under
this condition, the sensor exhibited excellent linearity (R
2 = 0.992), recoveries ranging from 78 to 108%,
and relative standard deviation (RSD) bellow 10% (n = 3). The limits of detection (LOD) and quantification (LOQ) were
0.5 and 1.7 μmol L–1 in synthetic urine and
3.0 and 10.1 μmol L–1 in egg sample, respectively.
The [Cu­(C8H4O4)]
n
/CPE sensor demonstrated high sensitivity and accuracy, highlighting
its potential as reliable tool for monitoring CIP residues in food
products and biological samples, thereby contributing to food safety
and public health.

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