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Electrochemical surface plasmon resonance (EC-SPR) aptasensor for ampicillin detection
摘要： Surface plasmon resonance technique is highly sensitive to various processes taking place on a metal film and it has emerged as a powerful label-free method to study molecular binding processes taking place on a surface. Another important but less explored area of applications is the use of hybrid methods which combine electrochemistry with optical methods for better monitoring and understanding of biochemical processes. A detection method based on surface plasmon resonance was developed for ampicillin, applying electrochemical techniques for the elaboration and characterization of the aptasensing platform used in this study. Ampicillin is a broad-spectrum β-lactam antibiotic, used both in human and veterinary medicine for the treatment and prevention of primary respiratory, gastrointestinal, urogenital, and skin bacterial infections. It is widely used because of its broad spectrum and low cost. This widespread use can result in the presence of residues in the environment and in food leading to health problems for individuals who are hypersensitive to penicillins. The gold chip was functionalized through potential-assisted immobilization, using multipulse amperometry, first with a thiol-terminated aptamer, as a specific ligand and secondly, using the same procedure, with mercaptohexanol, used to cover the unoccupied binding sites on the gold surface in order to prevent the nonspecific adsorption of ampicillin molecules. After establishing the optimal conditions for the chip functionalization, different concentrations of ampicillin were detected in real time, in the range of 2.5–1000 μmol L?1, with a limit of detection of 1 μmol L?1, monitoring the surface plasmon resonance response. The selectivity of the aptasensor was proven in the presence of other antibiotics and drugs, and the method was successfully applied for the detection of ampicillin from river water.
关键词： Multipulse amperometry,Electrochemical surface plasmon resonance (EC-SPR),Ampicillin,QCM,Antibiotic detection,SPR aptasensor
更新于2025-09-23 15:23:52
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Electrochemiluminecence nanogears aptasensor based on MIL-53(Fe)@CdS for multiplexed detection of kanamycin and neomycin
摘要： A dual gears electrochemiluminecence (ECL) aptasensing strategy for multiple selective determination of kanamycin and neocycin was designed on the basis of the combination of kannamycin and neocycin induced dual gears conversion, the loading platform of metal-organic frameworks (MOFs), surface plasmon resonance (SPR) and ECL resonance energy transfer (ERET) between CdS QDs and AuNPs (or PtNPs). In the absence of target, the dual gears were "off". Then the B1-AuNP (gear B) and aptamer 1-PtNPs acted as signal quenching elements to quench ECL intensity due to ERET process. Upon addition of kanamycin, the aptamer 1-PtNPs were removed from the gear gradually, the ECL was enhanced due to SPR process between AuNPs and CdS QDs. After the incubation of aptamer 2, the dual gears were "off" again and ECL intensity was decreased by ERET process between AuNPs and CdS QDs. In the presence of neomycin, dual gears were "on" again, the ECL signal was enhanced by SPR process between AuNPs and CdS QDs. Under optimal condition, the proposed aptasensor exhibited wide linear ranges of kanamycin (10-10- 10-6 M) and neomycin (10-9 -10-5 M), and relatively low detection limits to kanamycin (1.7×10-11 M) and neomycin (3.5×10-10 M). The developed aptasensor realized the multiple ECL detection of kanamycin and neomycin with single luminophore, and was successfully applied to the detection of kanamycin and neomycin in food samples.
关键词： electrochemiluminecence resonance energy transfer,electrochemiluminescence,antibiotic,nanogears,surface plasmon resonance
更新于2025-09-23 15:23:52
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Characterization and removal of antibiotic residues by NFC-doped photocatalytic oxidation from domestic and industrial secondary treated wastewaters in Meric-Ergene Basin and reuse assessment for irrigation
摘要： Antibiotics are important contaminants that have become an increasingly big problem due to the discharge of the receiving environment. The presence of these organic based pollutants in influent wastewater can inhibit the biological processes and resist to degradation in wastewater treatment plants. Moreover, the consumption of agricultural products, irrigated with water containing antibiotic residues, leads to major harmful effects to the human body through the food chain. In this study; firstly, a conventional characterization was made in terms of COD, TOC, SS, color and of antibiotic residue characterization of untreated raw (influent) and biologically treated (effluent) water from domestic and industrial wastewater treatment plants located in the Meri?-Ergene Basin. After that, photocatalytic activity test was run under visible light for selected antibiotics (Erythromycin, Ciprofloxacin, Sulphametoxasol) which were detected by HPLC MS/MS in excess amount. Finally, for the photocatalytic oxidation, a new generation NFC (Nitrogen-Floride-Carbon)-doped titanium dioxide photocatalyst, which has never been studied in the literature before, was prepared according to the sol-gel method without using thermal processing. Photocatalysts were characterized by UV–vis DRS reflectance and Laser Raman Spectra measurements. All other analyzes were made according to the standard methods. Considering the conventional characterization results; investigated domestic wastewaters exhibited moderate characteristics while industrial wastewater samples had strong characteristics in terms of COD, TOC and SS pollution in accordance with the literature. By the way, contrary to expectations, antibiotic residue results have proved that the effluent wastewater contains more antibiotics than the influent. This can be explained by the fact that, some antibiotics in domestic wastewaters are probably already trapped in feces and cannot be purified by conventional systems since they are released after biological treatment, as mentioned similar studies in the literature. Moreover, by means of 7 h NFC-doped photocatalytic oxidation under visible light, beside approximately % 62 to %79 COD and 62%–86% TOC removal, %99 to %100 removal of antibiotic residue was provided. According to these results, domestic and industrial secondary treated wastewaters in Meric-Ergene Basin can be advance treated, succesfully, with NFC-doped photocatalyst to remove antibiotic residues besides conventional pollutants. This result show that Meri?-Ergene discharge criteria determined by Forest and Water Ministry of Turkey can be provided with this new type photocatalytic process and healthy reuse of this river for irrigation will be possible.
关键词： Advanced oxidation processes,Domestic/industrial wastewater,Solvent-casting method,UV,Antibiotic,Photocatalyst,NFC-doped TiO2
更新于2025-09-23 15:22:29
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Solar photodegradation of oxytetracycline in brackish aquaculture water: New insights about effects of Ca2+ and Mg2+
摘要： Oxytetracycline (OTC) is an antibiotic used in aquaculture able to complex with the major cations Ca2+ and Mg2+, existing in brackish water. The effects of these cations on the solar photodegradation of OTC have been investigated. Calcium promotes a faster OTC photo-degradation in aqueous solution, while the same does not occur with Mg2+. For some authors the accelerating effect of Ca2+ is attributed to the occurrence of self-sensitized photodegradation of the complexes with Ca2+, which is not possible in the complexes with Mg2+, due to different binding patterns of these cations. In this work, the controversy concerning the binding sites of these cations in OTC is discussed. Based on spectroscopic evidence, similar binding patterns of OTC with Ca2+ and Mg2+ and a lower quantum yield of the direct photolysis of the complexes with Mg2+ are proposed. In addition, it was demonstrated that Mg2+ inhibits the formation of some OTC photoproducts observed in the presence of Ca2+, while at least two new OTC photoproducts are formed in the presence of Mg2+.
关键词： Photoproducts,Complexes,Quantum yields,Antibiotic,Photolysis,Spectroscopy
更新于2025-09-23 15:22:29
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Sono-solvothermal fabrication of ball-flowerlike Bi2O7Sn2-Bi7O9I3 nanophotocatalyst with efficient solar-light-driven activity for degradation of antibiotic tetracycline
摘要： A novel Bi2O7Sn2-Bi7O9I3 nano-heterostructure photocatalyst with the different weighted percentages and as I-type heterojunction, which acts as pseudo-type II heterojunction, were successfully synthesized using sono-solvothermal manner for the first time. The coupled nanophotocatalysts with various weighted contents of Bi2O7Sn2 and Bi7O9I3 were characterized with XRD, FESEM, EDX, DRS, BET-BJH and pHpzc analyses. Meanwhile, the photocatalytic activity of various nanocomposites was evaluated in the remediation of the antibiotic tetracycline after 90 min irradiation. Results depicted that the ball-flowerlike Bi2O7Sn2(60)-Bi7O9I3(40) nanophotocatalyst, as a mesoporous structure and the type I-heterostructure which appears as an efficient solar-light-driven pseudo-type II heterojunction, represented the best photocatalytic efficiency. This is addressed by the suitable absorption of light range, high separation of charge carriers and its large surface area which provide more active sites for absorption of tetracycline molecules. Furthermore, to elucidate the how the influence of various parameters on the photodegradation efficiency, the different experiments were conducted over Bi2O7Sn2(60)-Bi7O9I3(40). The high activity was obtained in the medium with pH = 6, catalyst loading = 1 g/L and tetracycline concentration = 35 mg/L. Moreover, the capable of reusability and reaction mechanism of improved photodegradation on mentioned photocatalyst were investigated.
关键词： Sono-solvothermal,Water treatment,Antibiotic tetracycline,Photodegradation,Bi2O7Sn2-Bi7O9I3 nanophotocatalyst
更新于2025-09-23 15:22:29
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Degradation of Ciprofloxacin and Inactivation of Ciprofloxacin Resistant E. Faecium during UV-LED (275 nm)/Chlorine Process
摘要： Ciprofloxacin and ciprofloxacin-resistant bacteria are emerging concerns that threaten public health due to the heavy use of antibiotics and the development of bacterial resistance in water environments. In this study, we examined an energy-efficient treatment driven by a UV-LED/chlorine reaction with UV-LED chip emitting UV275 nm to remove ciprofloxacin and ciprofloxacin-resistant bacteria in water. Ciprofloxacin degradation during the UV-LED/chlorine reaction followed pseudo-first-order kinetics, and the excessive chlorine dosage has a negative effect on ciprofloxacin removal. Alkaline pH showed the best efficiency for ciprofloxacin removal, and the reactive chlorine species (RCS) played a major role at alkaline pH values. The cleavages of piperazine, cyclopropyl, and quinolone moieties are considered as the principal degradation reactions in the UV-LED/chlorine reaction. Seven byproducts (m/z = 362.9262, 306.1246, 289.0995, 288.1504, 263.0825, 147.0657, and 1183.9977), two chlorinated compounds (chloroform and chlorate) and two anions (formate and nitrate ions) were observed as the identified byproducts. Toxicity of tentatively identified byproducts were estimated by using quantitative structure activity relationship (QSAR). The complete detoxification of D. magna was achieved when applying UV-LED/chlorine process into hospital wastewater containing CIP. The UV-LED/chlorine process showed the best disinfection ability of E. faecium compared to UV-LED photolysis, chlorination, and UV-LED/H2O2 reactions. A significantly lower EE/O value (6.63 × 10-2 kWh/m3/order) during the UV-LED/chlorine reaction was also observed. Our results indicate that the UV-LED/chlorine process can effectively degrade ciprofloxacin and inactivate ciprofloxacin-resistant bacteria.
关键词： toxicity,UV-LED,ciprofloxacin,byproducts,antibiotic-resistant bacteria,Chlorine
更新于2025-09-23 15:21:01
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Mobile Teaching and Learning of Coupled-Line Structures: The multiple-1D coupled-line finite-difference time-domain method.
摘要： Fever is one of the most common symptoms of illness in infants and represents a clinical challenge due to the potential for serious bacterial infection. As delayed treatment for these infections has been correlated with increased morbidity and mortality, broad-spectrum β-lactam antibiotics are often prescribed while waiting for microbiological lab results (1–3 days). However, the spread of antibiotic resistance via the β-lactamase enzyme, which can destroy β-lactam antibiotics, has confounded this paradigm; empiric antibiotic regimens are increasingly unable to cover all potential bacterial pathogens, leaving some infants effectively untreated until the pathogen is characterized. This can lead to lifelong sequela or death. Here, we introduce a fluorescent, microfluidic assay that can characterize β-lactamase derived antibiotic susceptibility in 20 min with a sensitivity suitable for direct human specimens. The protocol is extensible, and the antibiotic spectrum investigated can be feasibly adapted for the pathogens of regional relevance. This new assay fills an important need by providing the clinician with hitherto unavailable point of care information for treatment guidance in an inexpensive and simple diagnostic format.
关键词： beta-lactamase,Antibiotic resistance,point of care,microfluidic
更新于2025-09-23 15:21:01
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Visible light photocatalytic degradation of tetracycline with porous Ag/graphite carbon nitride plasmonic composite: Degradation pathways and mechanism
摘要： Ag/g-C3N4 plasmonic photocatalysts with porous structure ( Ag/PCN ) were successfully synthesized via a thermal exfoliation strategy and photo-reduction method. Owing to the combined merits of porous structure and surface plasmon resonance effect of silver nanoparticles, the Ag/PCN catalysts exhibited excellent photocatalytic performance for the degradation of antibiotic agents. With the optimal Ag loading, the Ag/PCN-2 catalyst exhibited the optimal catalytic activity for TC degradation under visible light, which shows about 11.8 times enhancement in the photocatalytic removal efficiency as compared to pure g-C3N4, respectively. This phenomenon can be attributed to the increased specific surface area, broadened visible light absorption and improved charge separation. The radical quenching results confirmed that h+ and ·O2- radicals were the major active species during removal of TC. The degradation of TC is increased with the increment of Ag/PCN-2 catalysts, and the optimum catalyst was found to be 1.67 g/L. The hindering effect of selected of anions ( Cl-, CO3-, H2PO4- ) was found to follow the order H2PO4- > CO3- > Cl-. Ag/PCN-2 sample also possessed high stability after six cycles of reuses. Furthermore, the possible degradation pathways of TC and photocatalytic mechanism over Ag/PCN-2 were proposed in detail.
关键词： g-C3N4,Antibiotic,Degradation pathway,Photocatalysis,Porous structure,Ag
更新于2025-09-23 15:21:01
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Integration of plasmonic heating and ona??chip temperature sensor for nucleic acid amplification assays
摘要： Nucleic acid tests have been widely used for diagnosis of diseases by detecting the relevant genetic markers that are usually amplified using polymerase chain reaction (PCR). This work reports the use of a plasmonic device as an efficient and low-cost PCR thermocycler to facilitate nucleic acid-based diagnosis. The thermoplasmonic device, consisting of a one-dimensional metal grating, exploited the strong light absorption of plasmonic resonance modes to heat up PCR reagents using a near-infrared laser source. The plasmonic device also integrated a thin-film thermocouple on the metal grating to monitor the sample temperature. The plasmonic thermocycler is capable of performing a PCR amplification cycle in approximately 2.5 minutes. We successfully demonstrated the multiplex and real-time PCR amplifications of the antibiotic resistance genes using the genomic DNAs extracted from Acinetobacter baumannii, Klebsiella pneumonia, Escherichia coli, and Campylobacter.
关键词： polymer chain reaction,thermoplasmonics,thermocycler,nucleic acid-based diagnostics,antibiotic resistance detection,Photothermal effect
更新于2025-09-23 15:19:57
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Photo-Fenton oxidative of pharmaceutical wastewater containing meropenem and ceftriaxone antibiotics: influential factors, feasibility, and biodegradability studies
摘要： The main aim of the present research, as the first study, was coupling of hydrogen peroxide (H2O2), ferrous ions (Fe2t) and UV irradiation in a photo-Fenton system to degradation two anti-biotics (e.g. meropenem and ceftriaxone) from aqueous solution. The tests were carried out at different experimental conditions namely solution pH, iron dosages, H2O2 concentrations, UV light intensities, temperatures, and initial antibiotic concentrations. The degradation rates of 99 and 96.2% were observed for respectively meropenem and ceftriaxone during 60 min treatment. Biodegradability tests illustrated that photo-Fenton system has a high performance in removing organic compounds and biodegradability enhanced remarkably after treatment.
关键词： homogeneous Fenton,mineralization,antibiotic degradation,Photo-Fenton oxidation,biodegradability
更新于2025-09-23 15:19:57