Full Green Detection of Antibiotic Tetracyclines Using Fluorescent Poly(ethylene glycol) as the Sensor and the Mechanism Study

Abstract

Tetracyclines are well-known antibiotics and widely used against a variety of bacterial infections. Their monitoring and detection have been an important issue. To this end, a vast number of methods have been developed; fluorescence sensing is one of the most reported. However, most of the reported sensors are made from transition metals with sophisticated multiprocesses; polymers are hardly seen for this purpose, particularly biocompatible ones. Herein, an aqueous solution of poly­(ethylene glycol) (PEG), well known for being biocompatible, is shown to emit under excitation of 280 nm, while the solutions of selected tetracyclines, namely, doxycycline (DOX) and tetracycline (TC), are non-emissive under the same conditions. In the binary solutions of PEG-DOX or PEG-TC, PEG emission is sharply quenched with high sensitivity and selectivity. PEG was then used as a sensor for DOX and TC detections in water with high performance compared to reported studies. The same tests were also done by DOX spiking in milk and tap water, demonstrating that DOX was practically fully recovered. The quenching mechanism was ascribed to the interaction between the O atoms of PEG in clusters and specific heteroatom groups on tetracycline molecules through hydrogen bonding, elucidated from FTIR and NMR analyses. Therefore, this work provides a novel, fully green, easy to operate, low cost, and reliable protocol for tetracycline monitoring and detection and opens new potential application for PEG.

Uniform and Fluorescent Poly(urea-siloxane) Microspheres: Preparation and Recyclable Use as Sensors for Cr6+ and Fe3+ Detection

“…Fortunately, a linearity was found by data fitting between the emission intensity I and [Cr 6+ ]: I = 4396.27–86.21 × [Cr 6+ ], with a correlation coefficient R 2 = 0.9966 (Figure B). From this linear relation, the detection limit (DL) was determined for Cr 6+ from a commonly known equation: ,, DL = K × σ/ S , where, K is a numerical factor (3 is usually taken to have a confidence level of 99.9%), σ is the standard deviation of the blank samples from at least 20 measures (5.65 in this work), and S is the slope of the linear curve of emission intensity versus [Cr 6+ ] (i.e., 86.21 here). The DL thus determined was 0.196 μmol/L (1.96 × 10 –7 mol/L).…”

Phase Transition and Fluorescence Emission of Multiresponsive Poly(ethylene glycol-co-siloxane) and Its Application for Uric Acid Detection

“…With the PEGDA increasing (APDS decreasing) from P1 to P8, the emission intensity was constant and regularly increased, indicating that the emission of PEG-Si mainly originates from the oligomer PEGDA rather than the ether-imide groups formed by aza-Michael addition. In fact, PEG and its (meth)­acrylated derivatives are reported to be fluorescent emissive, ,,, owing to the clustering of the oxygen atoms on their ethoxide segments and the terminal hydroxyls.…”

“…It is well-known that the emission of the CTE type of unconventional polymers is closely controlled by the size of their cluster and the size distribution. [18][19][20][21][22][23][24][25]28 These results mean that, in the presence of a low amount of NaCl, the clustering of P6 was promoted to a limited extent, yielding a slight increase in cluster size, for which the optional excitation light (275 nm) for the pure P6 solution (free of NaCl) is still highly effective to excite the clusters, leading to enhanced emission for [NaCl] up to 150 mmol/L. However, for the samples with [NaCl] above that concentration, the cluster size was increased to a far larger size than that at low [NaCl], e.g., 150 mmol or lower.…”

“…become one of the most exciting areas in fluorescent polymer research. 18−22 A vast number of CTE polymers, including polyurea, 23 polyethylene glycol, 24,25 polyamide, 26 and amide salt, 27 have been studied and potential applications explored. 23−28 N-Isopropylacrylamide (NIPAM)-based polymers, often referring to a series of widely studied temperature-responsive polymers, 29,30 are also reported to have CTE properties.…”

“…Poly­(ethylene glycol) (PEG) is renowned for its physiological inertia and nontoxicity, widely used in biotechnology and biomedical-related fields. ,, PEG-based thermoresponsive polymers have been reported recently, and their high lower critical solution temperature (LCST) can be lowered down to the biocompatible temperature range by incorporating hydrophobic groups. , The CTE behavior of PEG, , its acrylic copolymer, and the stimuli-responsiveness have been investigated . PEG–PDMS block copolymers were shown capable of aggregating and used for controlled drug release .…”