Fluorescent probe of quantum dots and zinc oxide in a highly selective polymer simultaneously determined florfenicol and sparfloxacin.

A nanocomposite fluorescent probe was fabricated for the simultaneous determination of florfenicol and sparfloxacin based on fluorescence quenching. The probe was synthesized by integrating nitrogen-doped graphene quantum dots (N-GQDs), cadmium telluride quantum dots (CdTe QDs) and zinc oxide nanoparticles (ZnO) into a molecularly imprinted polymer (MIP). The determination was based on the quenching of fluorescence emissions from N-GQDs by florfenicol, detected at 410 nm, and the quenching of fluorescence emissions from CdTe QDs by sparfloxacin, detected at 550 nm. The fluorescent probe was highly sensitive and specific with good linear relationships for florfenicol and sparfloxacin in the range  0.10 to 100.0 µg L-1. The limits of detection for florfenicol and sparfloxacin were 0.06 and 0.10 µg L-1, respectively. The fluorescent probe was used to determine florfenicol and sparfloxacin in food samples and the results agreed well with the results of chromatographic determination. Recoveries of spiked milk, egg and chicken samples reached 93.3-103.4% with good precision (RSD < 6%). The advantages of the nano-optosensor include high sensitivity and selectivity, simplicity, rapidity, convenience, good accuracy and precision.

A hierarchical porous composite magnetic sorbent of reduced graphene oxide embedded in polyvinyl alcohol cryogel for solvent-assisted-solid phase extraction of polycyclic aromatic hydrocarbons.

A hierarchical porouscomposite magnetic sorbent was fabricated and applied to the dispersive solvent-assisted solid-phase extraction of five polycyclic aromatic hydrocarbons. A sorbent was first prepared by incorporating graphene oxide, calcium carbonate, and magnetite nanoparticles into a polyvinyl alcohol cryogel. The graphene oxide was converted to reduced graphene oxide using ascorbic acid and a hierarchical porous structure was produced by reacting hydrochloric acid with incorporated calcium carbonate to generate carbon dioxide bubbles which created a second network. Before extracting the target analytes, the extraction solvent was introduced into the hierarchical pore network of the sorbent. The extraction was based on the partition between the analytes and introduced extraction solvent and the adsorption of analytes on reduced graphene oxide.The extraction efficiency was enhanced through π-π and hydrophobic interactions between polycyclic aromatic hydrocarbons and reduced graphene oxide and extraction solvent. The extracted polycyclic aromatic hydrocarbons were determined by using high-performance liquid chromatography coupled with a fluorescence detector. The developed method was applied to extract polycyclic aromatic hydrocarbons in disposable diaper, coffee, and tea samples and recoveries from 84.5 to 99.4% were achieved with relative standard deviations below 7%. The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.The developed sorbent exhibited good reproducibility and could be reused for 10 cycles.

A composite adsorbent of graphene quantum dots, mesoporous carbon, and molecularly imprinted polymer to extract nonsteroidal anti-inflammatory drugs in milk.

A composite magnetic adsorbent was developed by embedding graphene quantum dots (GQDs), silica-modified magnetite (Fe3O4-SiO2), and mesoporous carbon (MPC) into a molecularly imprinted polymer (GQDs/Fe3O4-SiO2/MPC/MIP). The adsorbent was applied to extract nonsteroidal anti-inflammatory drugs (NSAIDs) in milk. The MIP was formed via a sol-gel copolymerization using flurbiprofen, diflunisal, and mefenamic acid as template molecules, 3-aminopropyltriethoxysilane as a monomer, and tetraethyl orthosilicate as a cross-linker. GQDs and MPC enhanced affinity binding between NSAIDs and the adsorbent through π-π stacking, hydrogen bonding, and hydrophobic interaction. The Fe3O4-SiO2 nanoparticles embedded in the composite adsorbent enabled its rapid isolation from the sample solution. The extracted NSAIDs were quantified by high-performance liquid chromatography and exhibited good linearity from 1.0 to 100.0 µg L-1 for flurbiprofen and 0.5 to 100.0 µg L-1 for diflunisal and mefenamic acid, respectively. The limits of detection ranged from 0.5 to 1.0 µg L-1. Recoveries of NSAIDs from spiked milk samples ranged from 81.4 to 93.7%, with RSDs below 7%. The reproducibility of the fabricated adsorbent was good and in the optimal conditions, the developed adsorbent could be used for up to six extraction-desorption cycles.

In-syringe solid-phase extraction of polycyclic aromatic hydrocarbons using an iron-carboxylate metal-organic framework and hypercrosslinked polymer composite gelatin cryogel-modified cellulose acetate adsorbent.

Cellulose acetate fibers were modified with a gelatin cryogel adsorbent incorporating an iron-carboxylate metal-organic framework and hypercrosslinked polymer composite. The hybrid adsorption materials facilitated the adsorption ability toward polycyclic aromatic hydrocarbons and were entrapped into gelatin cryogel to be hierarchically coated on cellulose acetate fibers which helped to reduce the clogging problem of packed adsorbent. The composite adsorbent was employed as the solid phase of an in-syringe miniaturized solid-phase extraction system. The adsorbent was packed into the needle hub of a disposable syringe and used to extract and preconcentrate polycyclic aromatic hydrocarbons in water sample. The fabricated porous composite adsorbent was characterized and extraction conditions were optimized to achieve the best extraction performance. High-performance liquid chromatography was employed to separate and quantify extracted PAHs. The developed analysis method provided a linear range of 0.020-50 µg L-1 for phenanthrene and benzo(b)fluoranthene, 0.010-50 µg L-1 for pyrene, 0.0020-50 µg L-1 for benzo(a)anthracene, and 0.0050-50 µg L-1 for benzo(a)pyrene and dibenzo(a,h)anthracene. The limits of detection ranged from 0.5 to 5.0 ng L-1. Recoveries ranged from 89 to 98% with RSDs below 7%. The good stability of the adsorbent allowed up to 21 cycles of efficient extraction and desorption.

Solvent-assisted dispersive liquid-solid phase extraction of organophosphorus pesticides using a polypyrrole thin film-coated porous composite magnetic sorbent prior to their determination with GC-MS/MS.

A porous composite magnetic sorbent was developed and used as a solid phase for the solvent-assisted preconcentration of organophosphorus pesticides. The hierarchical porous composite sorbent was composed of polypyrrole thin film coated on the surface of porous alginate beads with embedded magnetite nanoparticles. The pores in the alginate hydrogel beads were produced by carbon dioxide bubbles from the reaction of incorporated calcium carbonate with hydrochloric acid. The porous network was filled with dichloromethane to assist extraction. The fabricated porous composite sorbent was characterized and sorbent fabrication and extraction conditions were optimized to obtain the best extraction performance. The developed sorbent was coupled with GC-MS/MS to determine organophosphorus pesticides in fruit juices and vegetable. Under optimized condition, the developed method provided good linear range of 0.03-200 µg L-1 for dichlorvos, malathion, and fenthion, and 0.075-200 µg L-1 for mevinphos, dimethoate, and parathion methyl, respectively. Limits of detection were in the range 0.010 to 0.025 µg L-1. This method exhibited good relative recoveries in the range 84 to 99% and RSDs lower than 8%. The good stability of the sorbent enabled up to eight cycles of reuse.Graphical abstract.

A nanocomposite probe of polydopamine/molecularly imprinted polymer/quantum dots for trace sarafloxacin detection in chicken meat.

A nanooptosensor based on the fluorescence quenching of a composite probe was fabricated for the detection of sarafloxacin. The components of the nanocomposite fluorescent probe were a high affinity material of polydopamine polymer (PDA), a selective material of molecularly imprinted polymer (MIP), and optically sensitive quantum dots (QDs). The developed nanocomposite fluorescent probe exhibited excellent selectivity and sensitivity for sarafloxacin. The molecularly imprinted polymer had an imprinting factor (IF) of 8.18 and produced a probe that quenched fluorescence more effectively than a non-imprinted polymer (NIP) probe. The emission intensity of the MIP probe was linearly quenched by sarafloxacin over a range of 0.10 to 15.0 µg L-1 with a determination coefficient (R2) of 0.9966. The developed nanooptosensor had a limit of detection of 0.05 µg L-1. The optosensor detected sarafloxacin in chicken meat samples with recoveries ranging from 82.8 to 99.1% with an RSD below 3%. The found concentrations in spiked samples were compared well with recoveries obtained by HPLC method of detection. This developed nanooptosensor is simple to operate and cost-effective and the analytical procedure is rapid. Graphical abstract.

A polypyrrole doped with fluorescent CdTe quantum dots and incorporated into molecularly imprinted silica for fluorometric determination of ampicillin.

A fluorometric method is described for the detection of ampicillin. A polypyrrole containing fluorescent CdTe quantum dots was incorporated into a silica-based molecularly imprinted polymer. The composite MIP displays good fluorescence (with excitation/emission maxima at 355/548 nm), and high selectivity and affinity for ampicillin due to the use of polypyrrole. Ampicillin is found to quench the fluorescence of composite much more strongly than the emission of a non-imprinted polymer. The imprinting factor of 7.5 implies that the nanocomposite probe contains specific binding sites. The MIP probe has two linear response ranges, one from 0.10 to 25 µg L-1 of ampicillin, and one from 25 to 100 µg L-1. The limit of detection is 0.05 µg L-1. The method was applied to the determination of ampicillin in (spiked) milk and meat samples and gave recoveries between 81.7 and 98.7%. The results agreed well with HPLC techniques. Graphical abstract Schematic presentation of nanocomposite fluorescence probe of polypyrrole and quantum dots incorporated in a molecularly imprinted polymer. Integrating of QDs, high specificity of MIPs and high affinity of polypyrrole, the method exhibited highly sensitive and selective for ampicillin detection.

A nanosorbent consisting of a magnetic molecularly imprinted polymer and graphene oxide for multi-residue analysis of cephalosporins.

A nanosorbent composed of magnetite nanoparticles, graphene oxide and a molecularly imprinted polymer (Fe3O4@SiO2-NH2/GOx/MIP) was synthesized and applied to simultaneous extraction of cephalexin, cefazolin and cefoperazone from milk. The use of magnetite nanoparticles enables fast extraction by using an external magnet. The use of graphene oxide increases extraction affinity, and the MIP improves selectivity. Extraction efficiency was optimized by investigating the effects of the template-to-monomer and cross-linker ratios, the desorption condition, extraction time, salting-out effect, stirring rate, sample volume and amount of adsorbent. The cephalosporins were quantified by using HPLC. Under optimum condition, the linear range of the method extends from 2.5 to 100 µg L-1 for cephalexin and cefazolin, and from 5.0 to 100 µg L-1 for cefoperazone. The limits of detection are 2.5 µg L-1 for cephalexin and cefazolin, and 5 µg L-1 for cefoperazone. The adsorbent was applied to the extraction of cephalosporins from milk, with recoveries in a range from 80.2 to 111.7% and with RSDs of <8.5%. Graphical abstractSchematic representation of a nanocomposite adsorbent consisting of magnetic molecularly imprinted polymer and graphene oxide (GOx). Integrating of magnetite nanoparticles, GOx and high specificity of MIP, the method exhibited a rapid, high extraction efficiency, good selectivity for multi-residue analysis of cephalosporins.

A hierarchically porous composite monolith polypyrrole/octadecyl silica/graphene oxide/chitosan cryogel sorbent for the extraction and pre-concentration of carbamate pesticides in fruit juices.

A hierarchically porous structured composite monolith sorbent of polypyrrole-coated graphene oxide and octadecyl silica incorporated in chitosan cryogel (PPY/GOx/C18/chitosan) was synthesized and used as solid-phase extraction sorbent for the determination of carbamate pesticides. Various factors affecting the characteristics of the adsorbents (chemistry of the sorbent, polymerization time, concentrations of graphene oxide and octadecyl silica) and the extraction efficiency using the prepared sorbents, such as sample loading, desorption conditions, sample volume, sample flow rate, sample pH, and ionic strength, were investigated and optimized. Under the optimal conditions of sorbent preparation and extraction, the developed composite monolith sorbent provided wide linear responses from 1.0 to 500 µg L-1 for carbofuran and diethofencarb, from 0.5 to 500 µg L-1 for carbaryl, and from 2.0 to 500 µg L-1 for isoprocarb. The limits of detection using HPLC-UV at 203, 220, and 208 nm were in the range of 0.5-2.0 µg L-1. When the composite monolith sorbent was applied for the pre-concentration and determination of carbamate in fruit juices, good recoveries (84.1-99.5%) were achieved. The developed sorbents were porous and exhibited low back pressure enabling their use at high flow rates during sample loading. Extraction and clean-up were highly efficient, and the good physical and chemical stability of the sorbent enables reuse up to 13 times. Graphical abstract ᅟ.

A miniaturized solid-phase extraction adsorbent of calix[4]arene-functionalized graphene oxide/polydopamine-coated cellulose acetate for the analysis of aflatoxins in corn.

A calix[4]arene-functionalized graphene oxide/polydopamine-coated cellulose acetate adsorbent was fabricated for the pre-concentration of aflatoxins. The highly porous developed adsorbent does not produce the high backpressure that normally occurs in particle-packed cartridges and its large surface area helps to improve adsorption. The highly efficient adsorption of aflatoxins by the hybrid adsorbent is facilitated via hydrogen bonding and hydrophobic and π-π interactions. Polymerization time, amount of calix[4]arene-functionalized graphene oxide, type and volume of desorption solvent, sample pH, sample volume, and sample flow rate were optimized. The linearity of aflatoxin B1 was in the range of 0.01-10.0 µg/kg, aflatoxin B2 was in the range of 0.02-10.0 µg/kg and aflatoxin G1 and aflatoxin G2 were in the range of 0.050-10.0 µg/kg. The limits of detection were 0.01 µg/kg for aflatoxin B1, 0.02 µg/kg for aflatoxin B2 and 0.05 µg/kg for aflatoxin G1 and aflatoxin G2. The developed calix[4]arene-functionalized graphene oxide/polydopamine-coated cellulose acetate adsorbent was successfully utilized for the analysis of aflatoxins from corn samples and the extraction efficiency was satisfactory with obtained recoveries from 83.0 to 106.7%. Moreover, fabricated adsorbent is easy to prepare, inexpensive, and can be reused.

A hybrid molecularly imprinted polymer coated quantum dot nanocomposite optosensor for highly sensitive and selective determination of salbutamol in animal feeds and meat samples.

A hybrid molecularly imprinted polymer (MIP)-coated quantum dot (QD) nanocomposite was synthesized and applied as a fluorescence probe for the highly sensitive and selective determination of salbutamol. The hybrid MIP-coated QD nanocomposite was synthesized via a copolymerization process in the presence of thioglycolic acid capped CdTe QDs with salbutamol as a template, 3-aminopropyltriethoxysilane as the functional monomer, and tetraethyl orthosilicate as a cross-linker. The optimum molar ratio of template, monomer, and cross-linker was 1:6:20. The fluorescence intensity of the hybrid MIP-coated QDs was efficiently quenched after salbutamol rebound to the recognition sites, as a result of charge transfer from QDs to salbutamol. The synthesized hybrid MIP-coated QD nanocomposite showed high sensitivity and good selectivity toward salbutamol. Under the optimal recognition conditions, the fluorescence intensity was quenched linearly with increasing concentration of salbutamol in the range from 0.10 to 25.0 µg L-1, with a detection limit of 0.034 µg L-1. The hybrid optosensor developed was successfully applied in the determination of salbutamol in animal feeds and meat samples. Satisfactory recoveries were obtained in the range from 85% to 98%, with a standard deviation of less than 8%. Furthermore, the accuracy of the hybrid MIP-coated QD nanocomposite was investigated by comparison with a conventional high-performance liquid chromatography method, with the results obtained with two methods agreeing well with each other. The advantages of this sensing method are simplicity, rapidity, cost-effectiveness, high sensitivity, and good selectivity. Graphical Abstract The synthesis of hybrid MIP-coated QDs nanocomposite.

Polypyrrole-coated alginate/magnetite nanoparticles composite sorbent for the extraction of endocrine-disrupting compounds.

Magnetite nanoparticles incorporated into alginate beads and coated with a polypyrrole adsorbent were prepared (polypyrrole/Fe3 O4 /alginate bead) and used as an effective magnetic solid-phase extraction sorbent for the extraction and enrichment of endocrine-disrupting compounds (estriol, ß-estradiol and bisphenol A) in water samples. The determination of the extracted endocrine-disrupting compounds was performed using high-performance liquid chromatography with a fluorescence detector. The effect of various parameters on the extraction efficiency of endocrine disrupting compounds were investigated and optimized including the type and amount of sorbent, sample pH, extraction time, stirring speed, and desorption conditions. Under optimum conditions, the calibration curves were linear in the concentration range of 0.5-100.0 µg/L, and the limit of detection was 0.5 µg/L. The developed method showed a high extraction efficiency, the recoveries were in the range of 90.5 ± 4.1 to 98.2 ± 5.5%. The developed sorbent was easy to prepare, was cost-effective, robust, and provided a good reproducibility (RSDs < 5%), and could be reused 16 times. The developed method was successfully applied for the determination of endocrine-disrupting compounds in water samples.

Polyaniline-coated cigarette filters as a solid-phase extraction sorbent for the extraction and enrichment of polycyclic aromatic hydrocarbon in water samples.

Polyaniline coated cigarette filters were successfully synthesized and used as a solid-phase extraction sorbent for the extraction and preconcentration of polycyclic aromatic hydrocarbons in water samples. The polyaniline helped to enhance the adsorption ability of polycyclic aromatic hydrocarbons on the sorbent through π-π interactions. The high porosity and large surface area of the cigarette filters helped to reduce backpressure and can be operated with high sample flow rate without loss of extraction efficiency. The developed sorbent was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The parameters that affected the extraction efficiencies, i.e. polymerization time, type of desorption solvent and its volume, sample flow rate, sample volume, sample pH, ionic strength, and organic modifier were investigated. Under the optimal conditions, the method was linear over the range of 0.5-10 µg/L and a detection limit of 0.5 ng/L. This simple, rapid, and cost-effective method was successfully applied to the preconcentration of polycyclic aromatic hydrocarbons from water samples. The developed method provided a high enrichment factor with good extraction efficiency (85-98%) and a relative standard deviation <10%.

A selective determination of copper ions in water samples based on the fluorescence quenching of thiol-capped CdTe quantum dots.

CdTe quantum dots (QDs) capped with different stabilizers, i.e. thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA) and glutathione (GSH) were investigated as fluorescent probes for the determination of Cu(2+). The stabilizer was shown to play an important role in both the sensitivity and selectivity for the determination of Cu(2+). TGA-capped CdTe QDs showed the highest sensitivity, followed by the MPA and GSH-capped CdTe QDs, respectively. The TGA- and MPA-capped CdTe QDs were not selective for Cu(2+) that was affected by Ag(+). The GSH-capped CdTe QDs were insensitive to Ag(+) and were used to determine Cu(2+) in water samples. Under optimal conditions, quenching of the fluorescence intensity (F0/F) increased linearly with the concentration of Cu(2+) over a range of 0.10-4.0 µg/mL and the detection limit was 0.06 µg/mL. The developed method was successfully applied to the determination of Cu(2+) in water samples. Good recoveries of 93-104%, with a relative standard deviation of < 6% demonstrated that the developed simple method was accurate and reliable. The quenching mechanisms were also described.

Polypyrrole/silica/magnetite nanoparticles as a sorbent for the extraction of sulfonamides from water samples.

A magnetic solid-phase extraction sorbent of polypyrrole/silica/magnetite nanoparticles was successfully synthesized and applied for the extraction and preconcentration of sulfonamides in water samples. The magnetite nanoparticles provided a simple and fast separation method for the analytes in water samples. The silica coating increased the surface area that helped to increase the polypyrrole layer. The polypyrrole-coated silica provided a high extraction efficiency due to the π-π and hydrophobic interactions between the polypyrrole and sulfonamides. Several parameters that affected the extraction efficiencies, i.e. the amount of sorbent, pH of the sample, extraction time, extraction temperature, ionic strength, and desorption conditions were investigated. Under the optimal conditions, the method was linear over the range of 0.30-200 µg/L for sulfadiazine and sulfamerazine, and 1.0-200 µg/L for sulfamethazine and sulfamonomethoxine. The limit of detection was 0.30 µg/L for sulfadiazine and sulfamerazine and 1.0 µg/L for sulfamethazine and sulfamonomethoxine. This simple and rapid method was successfully applied to efficiently extract sulfonamides from water samples. It showed a high extraction efficiency for all tested sulfonamides, and the recoveries were in the range of 86.7-99.7% with relative standard deviations of < 6%.

New sulfonate composite functionalized with multiwalled carbon nanotubes with cryogel solid-phase extraction sorbent for the determination of ß-agonists in animal feeds.

A new mixed-mode cation-exchange sulfonate composite functionalized with multiwalled carbon nanotubes with polyvinyl alcohol cryogel was fabricated and used for the first time as a solid-phase extraction sorbent for the determination of ß-agonists in animal feeds. Feed samples were extracted with 0.20 M phosphoric acid and methanol (1:4, v/v) using ultrasonication, cleaned-up using the developed sorbent to which the ß-agonists bound then finally eluted with 5.0% ammonia in methanol and analyzed by high-performance liquid chromatography. Various parameters that affected the extraction efficiency were optimized. Under the optimal conditions, the developed sorbent strongly interacted with ß-agonists by cationic exchange and hydrophobic and hydrophilic interactions, that provided a high extraction efficiency in the range of 92.8 ± 3.7-104.4 ± 2.3% over a range of 0.04-2.0 mg/kg for salbutamol and ractopamine, and 0.40-8.0 mg/kg for clenbuterol. The relative standard deviations were less than 6.0%. The developed method was successfully applied for the determination of ß-agonists in various types of animal feed and effectively reduced any matrix interference.

Mercaptopropionic acid-capped CdTe quantum dots as fluorescence probe for the determination of salicylic acid in pharmaceutical products.

Mercaptopropionic acid (MPA)-capped cadmium telluride (CdTe) quantum dot (QDs) fluorescent probes were synthesized in aqueous solution and used for the determination of salicylic acid. The interaction between the MPA-capped CdTe QDs and salicylic acid was studied using fluorescence spectroscopy and some parameters that could modify the fluorescence were investigated to optimize the measurements. Under optimum conditions, the quenched fluorescence intensity of MPA-capped CdTe QDs was linearly proportional to the concentration of salicylic acid in the range of 0.5-40 µg mL(-1) with a coefficient of determination of 0.998, and the limit of detection was 0.15 µg mL(-1). The method was successfully applied to the determination of salicylic acid in pharmaceutical products, and satisfactory results were obtained that were in agreement with both the high pressure liquid chromatography (HPLC) method and the claimed values. The recovery of the method was in the range 99 ± 3% to 105 ± 9%. The proposed method is simple, rapid, cost effective, highly sensitivity and eminently suitable for the quality control of pharmaceutical preparation. The possible mechanisms for the observed quenching reaction was also discussed.

A novel microextractor stick (polyaniline/zinc film/stainless steel) for polycyclic aromatic hydrocarbons in water.

A novel microextractor stick (MES) has been developed for the determination of trace amounts of polycyclic aromatic hydrocarbons (PAHs) in water samples. The proposed MES was prepared by electrodepositing a Zn-film onto a stainless steel stick followed by a coating with polyaniline (PANI) sorptive layers. This PANI/Zn-film/stainless steel stick produced a large surface area, provided a high extraction efficiency (82.0 ± 6.2% to 111.0 ± 7.5% recovery) of spiked chrysene (Chry) and benzo(a)pyrene (BaP). This MES is cost-effective, easy to prepare, robust and provides a good stick-to-stick reproducibility (n = 10) with a relative standard deviation of less than 10%. The effect of various parameters on the efficiency of extraction of PAHs were optimized, including the extraction time, extraction and desorption stirring speeds, volume of desorption solvent and desorption time. Under the optimum conditions, the limit of detection (S/N ≥ 3) and limit of quantification (S/N ≥ 10) of both Chry and BaP were 0.05 and 0.12 µg L(-1), respectively. The developed MES was successfully applied to determine PAHs in real water samples.

A magnetic imprinted polymer nano-adsorbent with embedded quantum dots and mesoporous carbon for the microextraction of triazine herbicides.

A magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@N-GQDs@Fe3O4NH2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding with triazines. The MIP layer provided highly specific recognition sites for the selective adsorption of three target triazines. The extracted triazines were determined by high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD). The developed method exhibited linearity from 1.5 to 100.0 µg L-1 with a detection limit of 0.5 µg L-1. Recoveries from spiked fruit juice samples were in the range of 80.1- 108.4 %, with a relative standard deviation of less than 6.0 %. The developed MMIP adsorbent demonstrated good selectivity, high extraction efficiency, ease of fabrication and use, and good stability.