Fluorescent Nanosensor Based on Molecularly Imprinted Polymers Coated on Graphene Quantum Dots for Fast Detection of Antibiotics

Abstract

In this work, we developed a novel fluorescent sensor by combining molecularly imprinted polymers (MIPs) with graphene quantum dots (GQDs) for the determination of tetracycline (TC) in aqueous samples. Firstly, we developed a one-pot green method to synthesize GQDs as the fluorescent probes. GQDs with carboxyl groups or amino groups were fabricated. It was found that carboxyl groups played an important role in the fluorescence quenching. Based on these findings, the GQDs-MIPs microspheres were prepared using a sol-gel process. GQDs-MIPs showed strong fluorescent emission at 410 nm when excited at 360 nm, and the fluorescence was quenched in the presence of TC. Under optimum conditions, the fluorescence intensity of GQDs-MIPs decreased in response to the increase of TC concentration. The linear rage was from 1.0 to 104 µg·L−1, and the limit of detection was determined to be 1 µg·L−1. The GQDs-MIPs also demonstrated high selectivity towards TC. The fluorescent sensor was successfully applied for the detection of TC in real spiked milk samples.

Triphenylphosphonium‐Derived Bright Green Fluorescent Carbon Dots for Mitochondrial Targeting and Rapid Selective Detection of Tetracycline

“…The quenching of C‐dots fluorescence with the addition of tetracycline was ascribed to the static quenching effect which was confirmed through the change of the absorbance spectrum of C‐dots with the addition of tetracycline that interacted with the fluorophore and induced static quenching, which affected the absorbance spectra of the quenching molecule (Figure 7). [13] In opposite, no change of absorbance spectra was observed in the case of dopamine‐C‐dot mixtures. The determined order of K SV magnitude also represents the static quenching where a stable complex might form between surface functional groups of C‐dots and tetracycline [34] .…”

“…It is also used as an additive in the stockbreeding farming industry, and its low cost offers excessive accessibility [12] . The presence of tetracycline residues in food such as egg, meats, milk, honey, and pharmaceuticals has received a great deal of concern [13] . These residues can stockpile in the human body through the food chain and cause adverse health effects including epigastic pain, dizziness, diarrhea, vomiting, anorexia, allergy, and headaches whereas long‐term exposure may affect the growth and formation of teeth, especially in children [14] .…”

“…Such types of functionalized nanoprobes suffer from multistep synthetic processes and decrement of fluorescence after conjugation, resulting in a shortage of efficient labeling. In addition, there are a lack of reports with bright luminescent and nude C‐dots (especially without any polymer support) where tetracycline selectivity has been presented compared to other drugs [11c,13] . Therefore, one‐pot synthesized, stable, and highly fluorescent C‐dots exhibiting effective mitochondria targeting and selective tetracycline detection is highly desirable.…”

Molecularly Imprinted Polymer Based Sensors for Medical Applications

“…In a molecularly imprinted polymer, specific sites can be created for various templates such as amino acids [43], proteins [44,45,46], enzymes [47,48], hormones [49,50,51], antibodies [52,53,54], nucleic acids [55,56], bacteria [57], viruses [58,59,60], drugs [61,62], metal ions [63,64,65,66], toxins [67], antibiotics [68] and pesticides [69,70] and so on. Furthermore, MIPs are easy to synthesis, highly stable, cost-effective, and user-friendly.…”

Nanocomposite-Based Graphene for Nanosensor Applications

“…Zhou et al designed and developed a convenient fluorescent sensor based on the molecularly imprinted polymers (MIPs)-functionalized GQDs for the detection of tetracycline (TC) with high sensitivity and high selectivity [25]. The GQDs were prepared by one-pot method, and the amino-functionalized GQDs and carboxylfunctionalized GQDs were fabricated, respectively.…”