RESUMEN
This study focused on detecting streptomycin (STR) residues using a luminescent aptasensor encapsulated with aptamer. Utilizing MOF-74-Co with peroxidase-like activity, luminol was enclosed in its pores. The specific STR aptamer acted as a gatekeeper, ensuring excellent performance. Upon exposure to STR, the aptamers detached, releasing luminol and amplifying the luminescent signal through MOF-74-Co catalytic activity. A linear relationship between fluorescence intensity and STR concentration (50 nM â¼ 5 × 106 nM) was established, with a limit of detection of 0.065 nM. The sensor exhibited high selectivity for STR even in the presence of other aminoglycoside antibiotics. Applied to tea, egg, and honey samples, the sensor showed recovery rates of 91.38-100.2%, meeting safety standards. This MOF-based aptasensor shows promise for detecting harmful residues.
Asunto(s)
Aptámeros de Nucleótidos , Contaminación de Alimentos , Miel , Luminol , Estreptomicina , Luminol/química , Estreptomicina/química , Estreptomicina/análisis , Aptámeros de Nucleótidos/química , Contaminación de Alimentos/análisis , Miel/análisis , Técnicas Biosensibles/instrumentación , Antibacterianos/análisis , Antibacterianos/química , Límite de Detección , Estructuras Metalorgánicas/química , Té/química , Mediciones Luminiscentes/instrumentación , LuminiscenciaRESUMEN
Due to the high demand for honey, beekeepers often feed the bees with antibiotics to protect honeybees against illnesses; the determination of veterinary drugs and their residues in bee products especially in honey is gaining importance. In this study, commercially available 15 different brands, a total of 22 honey (14 blossoms and 8 pines) samples obtained from 5 chain supermarkets in the city of Bingöl and Diyarbakir, Turkey were analysed for 29 antibiotic residues. These antibiotics belong to 10 different categories, including tetracyclines, aminoglycosides, macrolides, sulfonamides, fluoroquinolones, benzimidazoles, anthelmintic, amphenicols, quinolines, and oxazolidines. For the qualitative and quantitative determination of the antibiotics, a triple quadrupole liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used. A total of 10 out of 22 honey (8 blossom, 57.14 % and 2 pine, 25 %) samples were found to be positive for antibiotics. Among the tested antibiotics, tetracycline, dihydrostreptomycin, streptomycin, erythromycin, and sulfadimidine were detected in the honey samples. Dihydrostreptomycin and sulfadimidine were detected in 6 samples, erythromycin was determined in 4 samples, streptomycin was found in 2 samples, and lastly, tetracycline was detected only in one sample. The highest and the lowest concentrations of antibiotics detected in the samples were dihydrostreptomycin and erythromycin found at the amount of 992.58â µg/kg and 0.77â µg/kg respectively. The proposed method was validated with a limit of quantification (LOQ) and limit of detection (LOD) ranging between 0.42 and 3.22â µg /kg and 0.13-0.97â µg /kg respectively. Good linearities were also achieved ranging between R2 =0.987 and 0.999.
Asunto(s)
Sulfato de Dihidroestreptomicina , Miel , Abejas , Animales , Antibacterianos/análisis , Miel/análisis , Sulfato de Dihidroestreptomicina/análisis , Espectrometría de Masas en Tándem/métodos , Tetraciclina , Sulfametazina/análisis , Cromatografía Liquida/métodos , Cromatografía Líquida con Espectrometría de Masas , Estreptomicina/análisis , EritromicinaRESUMEN
Today, the emergence of antibiotic resistance in pathogenic bacteria is considered an important problem for society. Excessive consumption of antibiotics, long-term treatments, and inappropriate prescriptions continually increase the severity of the problem. Improving antibiotic stewardship requires improved diagnostic testing, and, therefore, in vitro antibiotic susceptibility testing is becoming increasingly important. This research details the development of an antibiotic susceptibility test for Mycobacterium smegmatis using streptomycin as antibiotics. This strain was selected because it is a member of the slow growing Mycobacterium genus and serves as a useful surrogate organism for M. tuberculosis. A commercially available and low-cost screen-printed gold electrode in combination with a specifically developed nucleic acid probe sequence for the 16SrRNA region of the mycobacterial genome was employed to monitor M. smegmatis nucleic acid sequences using the techniques of square-wave voltammetry and electrochemical impedance spectroscopy. The results show that it was possible to detect M. smegmatis sequences and distinguish antibiotic-treated cells from untreated cells with a label-free molecular detection. As a result, the in vitro antibiotic susceptibility test revealed that M. smegmatis showed sensitivity to streptomycin after a 24-H incubation, with the developed protocol representing a potential approach to determining antibiotic susceptibility more quickly and economically than current methods.
Asunto(s)
Antituberculosos/análisis , Oro/química , Estreptomicina/análisis , Antituberculosos/farmacología , Electrodos , Oro/economía , Pruebas de Sensibilidad Microbiana , Mycobacterium smegmatis/efectos de los fármacos , Estreptomicina/farmacologíaRESUMEN
Colorimetric analytical strategies exhibit great promise in developing on-site detection methods for antibiotics, while substantial recent research efforts remain problematic due to dissatisfactory sensitivity. Taking this into account, we develop a novel colorimetric sensor for in-field detection of antibiotics by using aptamer (Apt)-capped and horseradish peroxidise (HRP)-embedded zeolitic metal azolate framework-7 (MAF-7) (Apt/HRP@MAF-7) as target recognition and signal transduction, respectively. With the substrate 3,3',5,5'-tetramethylbenzidine (TMB)-impregnated chip attached on the lid, the assay can be conveniently operated in a tube and reliably quantified by a handheld colorimeter. Hydrophilic MAF-7 can not only prevent HRP aggregation but also enhance HRP activity, which would benefit its detection sensitivity. Besides, the catalytic activity of HRP@MAF-7 can be sealed through assembling with Apt and controllably released based on the bioresponsivity via forming target-Apt complexes. Consequently, a significant color signal can be observed owing to the oxidation of colorless TMB to its blue-green oxidized form oxTMB. As a proof-of-concept, portable detection of streptomycin was favorably achieved with excellent sensitivity, which is superior to most reported methods and commercial kits. The developed strategy affords a new design pattern for developing on-site antibiotics assays and immensely extends the application of enzyme embedded metal-organic framework composites.
Asunto(s)
Antibacterianos/análisis , Aptámeros de Nucleótidos/química , Enzimas Inmovilizadas/química , Peroxidasa de Rábano Silvestre/química , Estructuras Metalorgánicas/química , Estreptomicina/análisis , Bencidinas/química , Técnicas Biosensibles , Catálisis , Colorimetría , Colorantes/química , Límite de Detección , Oxidación-Reducción , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Misuse of antibiotics in veterinary medicine has the potential to generate residues in animal derived products, which could contributing to the development of an important health risk either through the exposure to antibiotic residues or the transfer of antibiotic resistance among foodborne pathogens as well. Tetracycline (TE) and eptomycin (ST) are commonly used as antibiotics in the Egyptian animal husbandry. The objective of this study, quick detection of TE and ST in fresh local beef tissue samples using radioimmunoassay Charm II technique, isolation and identification of relevant highly resistant bacterial strains. In addition to investigating the effect of gamma radiation on the susceptibility of such resistant strains to TE and ST. RESULTS: Tetracycline (TE) was detected in all collected samples, while ST was detected in 38.46% (5/13) and 87.5% (7/8) of meat and liver samples, respectively. Fifty-one bacterial isolates were isolated from the tested samples, among them, the highest resistant isolates to TE or ST were identified as Streptococcus thoraltensis, Proteus mirabilis (2 isolates) and E. coli (3 isolates). Among them, the highest D10-values in phosphate buffer; 0.807 and 0.480; kGy were recorded with S. thoraltensis and E. coli no.3, respectively. Such values increased to record 0.840 and 0.549 kGy, respectively after artificial inoculation into meat, indicating increased resistance to gamma radiation. Gamma radiation at dose 3 kGy increased the susceptibility of S. thoraltensis up to 50% to TE and ST, while the sensitivity of E. coli no.3 reached up 56% to both antibiotics at the same dose. CONCLUSIONS: High prevalence of TE in all fresh collected tissue samples suggests an extensively use of TE as antimicrobial in conventional beef production as compared to ST in the Egyptian cows' husbandry. Moreover, irradiation of food from animal origin by gamma radiation could potentially provide protection against resistant strains. In spite of limited samples used in this study, our data could raise the concerns of public health professionals about a withdrawal period before animals slaughtering, and address the importance of gamma radiation to minimize the hazards of foodborne resistant bacteria.
Asunto(s)
Bacterias/clasificación , Farmacorresistencia Bacteriana , Productos de la Carne/análisis , Estreptomicina/análisis , Tetraciclina/análisis , Crianza de Animales Domésticos , Animales , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Bacterias/efectos de la radiación , Bovinos , Farmacorresistencia Bacteriana/efectos de la radiación , Egipto , Microbiología de Alimentos , Rayos gamma , Productos de la Carne/microbiología , Pruebas de Sensibilidad MicrobianaRESUMEN
A self-powered aptasensor for streptomycin detection was constructed with a photofuel cell combined with a capacitor and a digital multimeter. The sensitivity of the proposed sensor was 8.7 times of that without using a capacitor amplifier circuit.
Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Electroquímicas/métodos , Estreptomicina/análisis , Ácido Ascórbico/química , Electrodos , Oro/química , Grafito/química , Luz , Nanopartículas del Metal/química , Nanocompuestos/química , Oxidación-Reducción , Compuestos de Estaño/químicaRESUMEN
A MOF-based bio-bar code material was synthesized and firstly applied to develop an electrochemical streptomycin (STR) aptasensor. By using MOF-based bio-bar code and enzyme-assisted target recycling for dual-signal amplification, highly sensitive detection of STR was achieved. The sensing surface was simply fabricated by immobilizing a mixed monolayer of thiolated cDNA/aptamer duplexes (dsDNA) and 6-mercapto-1-hexanol (MCH) on the gold nanoparticle modified screen printed carbon electrode (Au/SPCE). The presence of target STR caused highly efficient removal of the aptamers from dsDNA assisted by Exo I enzyme. Then MOF-based bio-bar codes were backfilled to achieve the adsorption of electroactive Ru(NH3)63+ (RuHex) on electrode surface. The electrochemical signal of the surface-confined RuHex was used for quantitation. The analytical performance for STR was satisfactory with a wide linear range of 0.005-150 ng mL-1, a low detection limit of 2.6 pg mL-1 and a good selectivity towards other three antibiotics. Moreover, the application of this aptasensor for determination of STR in real milk samples was also realized. With these merits, this dual-signal amplification assay might provide one of the effective ways for food safety monitoring.
Asunto(s)
Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Contaminación de Alimentos/análisis , Estructuras Metalorgánicas/química , Leche/química , Estreptomicina/análisis , Animales , Aptámeros de Nucleótidos/química , Límite de Detección , Estreptomicina/químicaRESUMEN
Antibiotic residues are major contaminants in milk because of their use in agriculture and animal husbandry. In particular, streptomycin, an aminoglycoside antibiotic, is a potential risk to consumers because of its ototoxicity, anaphylaxis, and growth inhibition. Herein, monoclonal antibodies for streptomycin were conjugated with europium microspheres to serve as detection probes for the development of a chromatographic time-resolved fluoroimmunoassay to detect streptomycin residues in milk. The method had a low detection limit of 0.58 µg/kg, a linear range of 0.8 to 6.25 µg/kg, and substantial recovery, from 85.6 to 108.3%. It showed slight cross-reactivity with another aminoglycoside analog. Strong correlations between the results of established chromatographic time-resolved fluoroimmunoassay and ultra-performance liquid chromatography-tandem mass spectrometry indicated that the established fluoroimmunoassay is a reliable method for rapid onsite detection of streptomycin in milk and it has great potential in food safety monitoring.
Asunto(s)
Antibacterianos/análisis , Fluoroinmunoensayo/veterinaria , Leche/química , Estreptomicina/análisis , Animales , Anticuerpos Monoclonales/inmunología , Cromatografía Liquida/veterinaria , Residuos de Medicamentos/análisis , Fluoroinmunoensayo/métodos , NanopartículasRESUMEN
Antibiotics are considered emerging pollutants which indiscriminate use has led to the development of antibiotic-resistant bacteria, while their improper disposal has caused adverse effects to the environment and human health. Thus, the development of devices or techniques capable of detecting antibiotics with high sensitivity, low detection limits, and reasonable cost becomes of prime importance. In this work, an electronic tongue (e-tongue) based on molybdenum disulfide (MoS2) and graphene oxide (GO) was developed and employed to detect four distinct antibiotics, namely cloxacillin benzathine, erythromycin, streptomycin sulfate, and tetracycline hydrochloride. The five sensing units of the e-tongue were obtained using the drop-casting method to modify gold interdigitated electrodes with MoS2 and GO. Using Principal Component Analysis to process the experimental data allowed the e-tongue to recognize samples contaminated with distinct antibiotics at varied concentrations from 0.5 to 5.0 nmol L-1. Analyses with real samples were also performed using river water and human urine and the electronic tongue was able to differentiate the samples at a nanomolar level. The proposed system represents a sensitive and low-cost alternative for antibiotic analyses in different liquid media.
Asunto(s)
Antibacterianos/análisis , Disulfuros/química , Nariz Electrónica , Grafito/química , Molibdeno/química , Cloxacilina/análisis , Electrodos , Eritromicina/análisis , Oro/química , Humanos , Estructura Molecular , Estreptomicina/análisis , Tetraciclina/análisisRESUMEN
In photoelectrochemical sensor (PEC sensor), sensitivity and selectivity are two essential factors which are determined by photosensitive of materials and identification of elements. Herein, a novel PEC aptamer sensor for streptomycin-specific detection was developed, with which the visible-light-active TiO2/BiOI/BiOBr heterostructure and aptamers were employed as photoactive material and bio-identification elements, separately. The combination of an appropriate amount of TiO2 with BiOI/BiOBr enhanced the photocurrent response, and thus is beneficial to the construction of PEC sensors. In addition, the one-pot synthesis of TiO2/BiOI/BiOBr has the advantage of being environmentally-friendly. Under optimized conditions, the photocurrent response of aptamer/TiO2/BiOI/BiOBr/ITO is linear with SRT concentration from 0.05 to 150 nM, and the detection limit (S/N = 3) is as low as 0.04 nM. This novel PEC sensing strategy provided an ultra-sensitive sensor with high selectivity and stability for SRT detection.
Asunto(s)
Aptámeros de Nucleótidos/química , Bismuto/química , Técnicas Electroquímicas , Estreptomicina/análisis , Titanio/química , Técnicas Biosensibles , Estructura Molecular , Procesos FotoquímicosRESUMEN
Antibiotics can affect microbial community structure and promote antibiotic resistance. However, the course of microbial community recovery in wastewater treatment systems after antibiotic disturbance remains unclear. Herein, multiple molecular biology tools, including 16S amplicon sequencing, GeoChip 5.0, quantitative polymerase chain reaction (qPCR), and metagenomic sequencing, were used to investigate the year-long (352 d) recovery of the microbial community functional structure in an aerobic biofilm reactor. Nitrification was completely inhibited under 50 mg/L of streptomycin spiking (STM_50) due to the significant reduction of ammonia-oxidizing bacteria, but recovered to original pre-disturbance levels after streptomycin removal, indicating the high resilience of ammonia-oxidizing bacteria. Bacterial community richness and diversity decreased significantly under STM_50 (p < 0.05), but recovered to levels similar to those observed before disturbance after 352 d. In contrast, bacterial composition did not recover to the original structure. The carbon degradation and nitrogen cycling functional community significantly changed after recovery compared to that observed pre-disturbance (p < 0.05), thus indicating functional redundancy. Additionally, levels of aminoglycoside and total antibiotic resistance genes under STM_50 (relative abundance, 0.33 and 0.80, respectively) and after one year of recovery (0.12 and 0.29, respectively) were higher than the levels detected pre-disturbance (0.04 and 0.24, respectively). This study provides an overall depiction of the recovery of the microbial community functional structure after antibiotic exposure. Our findings give notice that recovery caused by antibiotic disturbance in the water environment should be taken more seriously, and that engineering control strategies should be implemented to prevent the antibiotic pollution of wastewater.
Asunto(s)
Antibacterianos/toxicidad , Biopelículas/efectos de los fármacos , Reactores Biológicos/microbiología , Microbiota/efectos de los fármacos , Estreptomicina/toxicidad , Contaminantes Químicos del Agua/toxicidad , Purificación del Agua/métodos , Aerobiosis , Antibacterianos/análisis , Biopelículas/crecimiento & desarrollo , Carbono/metabolismo , Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Metagenoma/efectos de los fármacos , Microbiota/genética , Nitrificación , Nitrógeno/metabolismo , Estreptomicina/análisis , Aguas Residuales/química , Aguas Residuales/microbiología , Contaminantes Químicos del Agua/análisisRESUMEN
Streptomycin (STR) and dihydrostreptomycin (DSTR) are two of the most common aminoglycoside antibiotics used in veterinary medicine. STR is produced by some streptomyces griseus strains, and DSTR is a derivative of STR. In recent years, STR has been widely used in grapes to induce denuclearization. However, high levels of STR may have adverse effects like serious ototoxicity and nephrotoxicity. Therefore, to ensure the quality of grapes and the health of consumers, the regulation of STR and DSTR levels in grapes is required. An analytical method was developed for the identification and quantification of STR and DSTR in grapes by liquid chromatography-tandem mass spectrometry (LC-MS/MS). STR and DSTR are highly polar compounds due to the presence of various amino and hydroxyl groups in their structure. The determination of STR and DSTR poses a considerable analytical challenge, both during sample preparation and instrument analysis. In this study, the main factors governing the response, recovery, and sensitivity of these compounds, such as the type of chromatographic column, the type and proportion of the mobile phase and extraction solvent, the dosage of sodium 1-hexane sulfonate solution, and elution solvent and its volume, were investigated during sample pretreatment and instrument analysis. The STR and DSTR residues in the grape sample were extracted by ultrasonication with a phosphoric acid solution (pH 2), and cleanup and enrichment was performed using an Oasis HLB solid phase column. The analysis was performed using a UPLC Waters HSS T3 column (100 mm×2.1 mm, 1.8 µm) at the column temperature of 35â. The injection volume was 2 µL. The mobile phase consisted of 0.1% formic acid aqueous solution and methanol with a volume ratio of 60:40. ESI-MS/MS was operated in multiple reaction monitoring (MRM) mode. External standard calibration curves were used for quantification. Based on the optimized method, both analytes displayed good linearity between 2 and 400 µg/L. The correlation coefficients were 0.9991-0.9997. Recoveries in spiked blank grape samples (5, 10, 20, and 40 µg/kg) ranged from 76.8% to 91.9%, with the relative standard deviations (RSDs) less than 10.2%, in compliance with the current legislation. The limits of detection and the limits of quantification of both analytes were 1 µg/L and 5 µg/kg, respectively. To assess the feasibility and potential of the proposed approach for routine analyses of STR and DSTR in other kinds of grape samples, the developed method was applied to the analysis of these compounds in red grapes, xinyu grapes, and xiahei grapes. The recoveries of STR and DSTR in the three kinds of blank grape samples were 77.2%-83.9% and 70.8%-78.9%, respectively, and the RSDs ranged from 3.0% to 15.6%. The results showed that the optimized methods can yield satisfactory recoveries for the analytes in grapes. In this method, the combination of Waters HSS T3 column to overcome the difficulties of the retention and separation of these highly polar compounds in the reverse phase, avoids the use of an ion-pair additive in the mobile phase to increase their retention, which is known to cause severe contamination of the column and serious ion suppression with electrospray ionization detection. In addition, the ideal enrichment and purification effect can be achieved by adding a sodium 1-hexane sulfonate solution to the superstratum extract with the use of only Oasis HLB for sample treatment. The method described herein has the advantages of easy operation, accuracy, and selectivity, making it feasible for the identification and quantification of STR and DSTR residues in grapes.
Asunto(s)
Sulfato de Dihidroestreptomicina/análisis , Residuos de Medicamentos/análisis , Frutas/química , Estreptomicina/análisis , Vitis/química , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Análisis de los Alimentos , Contaminación de Alimentos , Extracción en Fase Sólida , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: The low cost of aminoglycoside (AMG) antibiotics facilitates their excessive use in animal husbandry and the agriculture sector. This scenario has led to the occurrence of residues in the food chain. After several years of AMG use in antibacterial therapy, resistance to streptomycin has begun to appear. Most of the detection methods developed for AMG antibiotics lacks specificity. A broad target specific nanoprobe would be ideal for detecting the entire class of AMGs. A rapid and sensitive method for the detection of AMGs is urgently needed. RESULTS: Gallic acid-coated silver nanoparticles (AgNPs) were demonstrated as a nanoprobe for the colorimetric detection of AMGs (yellow to orange / red). A linear dynamic range of 50-650 pmol L-1 was achieved readily by ratiometric spectrophotometry (A560 /A400 ) with a limit of detection (LOD) as low as 36 pmol L-1 . The amine-groups of the AMGs function as molecular linkers, so that electrostatic coupling interactions between neighboring particles drive the formation of AgNP aggregates. The assay can also be applied for the determination of streptomycin residues in serum and milk samples. CONCLUSION: This study revealed the potential of an AgNP probe for the rapid and cost-effective detection of low-molecular-weight target analytes, such as the AMGs. A ligand-induced aggregation of AgNPs coated with gallic acid was reported to be a rapid and sensitive assay for AMGs. Analysis of streptomycin was demonstrated with excellent picomolar-level sensitivity. Thus, the validated method can find practical applications in the ultrasensitive detection of AMGs in complex and diagnostic settings. © 2019 Society of Chemical Industry.
Asunto(s)
Antibacterianos/análisis , Colorimetría/métodos , Residuos de Medicamentos/análisis , Leche/química , Suero/química , Estreptomicina/análisis , Agua/química , Animales , Antibacterianos/farmacología , Bovinos , Colorimetría/instrumentación , Límite de Detección , Nanopartículas del Metal/química , Plata/químicaRESUMEN
A digital fluorescence detector (DFD), a handheld fluorescence detection device, can convert the fluorescence signal of samples into the corresponding fluorescer concentration. Herein, by adopting a DFD as the readout, a novel intelligent platform was developed based on a ratiometric paper-based device (RPD) for multiple aminoglycoside detection. There are five layers and four parallel channels contained in the designed RPD, functioning as reagent storage, fluidic path control and signal processing, respectively. The rationale of this design lies in the fact that aptamer/graphitic carbon nitride nanosheet (Apt/g-C3N4 NS) modified layers can catalyze o-phenylenediamine to fluorescent 2,3-diaminophenazine (DAP) in the presence of H2O2. When Apt was removed from nanosheets via the Apt-target reaction, the peroxidase-like activity would be decreased, thus decreasing the production of DAP. All the changes of the fluorescence DAP signal can be read out using a portable DFD. Based on the DFD signal change related to the concentration of the target, a quantitative reaction platform was established. Furthermore, the sample flow and Apt-target reaction time can be reasonably regulated using the H2O2-cleavable hydrophobic compound modified layer placed between the target recognition region and detection region. Then, the practicality of this platform was verified through realizing sensitive analysis of streptomycin, tobramycin, and kanamycin simultaneously. Overall, with merits including portability and ease of operation, the platform shows great potential in on-site simultaneous detection of multiple targets, especially in resource-limited settings.
Asunto(s)
Antibacterianos/análisis , Kanamicina/análisis , Papel , Espectrometría de Fluorescencia/métodos , Estreptomicina/análisis , Tobramicina/análisis , Animales , Antibacterianos/química , Aptámeros de Nucleótidos/química , Fluorescencia , Colorantes Fluorescentes/química , Contaminación de Alimentos/análisis , Grafito/química , Peróxido de Hidrógeno/química , Kanamicina/química , Límite de Detección , Leche/química , Nanoestructuras/química , Compuestos de Nitrógeno/química , Fenazinas/química , Fenilendiaminas/química , Reproducibilidad de los Resultados , Ríos/química , Espectrometría de Fluorescencia/instrumentación , Estreptomicina/química , Tobramicina/química , Contaminantes Químicos del Agua/análisisRESUMEN
In this work, a metallic composite with strong electrocatalytic property was designed by uniformly decorating Pt and Sn nanoparticles on the surface of TiO2 nanorods (Pt-Sn@TiO2). A detection scheme was then developed based on a dual signal amplification strategy involving the Pt-Sn@TiO2 composite and exonuclease assisted target recycling. The Pt-Sn@TiO2 composite exhibited an enhanced oxygen reduction current owing to the synergistic effect between Pt and Sn, as well as high exposure of Pt (111) crystal face. Initially, a Pt-Sn@TiO2 modified glassy carbon electrode produced an amplified electrochemical signal for the reduction of dissolved oxygen in the analyte solution. Next, a DNA with a complementary sequence to a streptomycin aptamer (cDNA) was immobilised on the Pt-Sn@TiO2 modified electrode, followed by the streptomycin aptamer that hybridised with cDNA. The corresponding oxygen reduction current was diminished by 51% attributable to the hindrance from the biomolecules. After a mixture of streptomycin and RecJf exonuclease was introduced, both the streptomycin-aptamer complex and the cDNA were cleaved from the electrode, making the Pt-Sn and Pt (111) surface available for oxygen reduction. RecJf would also release streptomycin from the streptomycin-aptamer complex, allowing it to complex again with aptamers on the electrode. This has then promoted a cyclic amplification of the oxygen reduction current by 85%, which is quantitatively related to streptomycin. Under optimal conditions, the aptasensor exhibited a linear range of 0.05-1500â¯nM and a limit of detection of 0.02±0.0045â¯nM streptomycin. The sensor was then used in the real-life sample detection of streptomycin to demonstrate its potential applications to bioanalysis.
Asunto(s)
Antibacterianos/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Nanocompuestos/química , Estreptomicina/análisis , Titanio/química , Animales , Técnicas Electroquímicas/instrumentación , Diseño de Equipo , Análisis de los Alimentos/instrumentación , Límite de Detección , Leche/química , Nanocompuestos/ultraestructura , Oxidación-Reducción , Oxígeno/química , Platino (Metal)/química , Estaño/químicaRESUMEN
An analytical method was developed for the determination of streptomycin and dihydrostreptomycin in honey using hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The streptomycin and dihydrostreptomycin residues in the test samples were extracted with 20 g/L trichloroacetic acid aqueous solution (including 50 mmol/L phosphate, pH 6.8) and cleaned on an Oasis HLB solid phase extraction column. The products were separated on a SIELC Obelisc R column with gradient elution using 0.5% (v/v) formic acid aqueous solution and acetonitrile as mobile phases. Streptomycin and dihydrostreptomycin were detected by liquid chromatography-tandem mass spectrometry in the positive ion mode using the external standard method. Under the optimal conditions, streptomycin and dihydrostreptomycin showed good linearity (r>0.99) in the range of 2.5-100 µg/L. The LOD and LOQ of the method was 2.0 µg/kg and 5.0 µg/kg, respectively. The spiked recoveries of the analytes from blank honey samples at the three levels of 5.0, 20.0 and 100.0 µg/kg were in the range of 86.9%-113.2% with the relative standard deviations less than 10%. With the advantages of convenience, rapidity, sensitivity and good repeatability, the method is suitable for the detection of streptomycin and dihydrostreptomycin in honey.
Asunto(s)
Sulfato de Dihidroestreptomicina/análisis , Residuos de Medicamentos/análisis , Miel/análisis , Estreptomicina/análisis , Cromatografía Liquida , Interacciones Hidrofóbicas e Hidrofílicas , Extracción en Fase Sólida , Espectrometría de Masas en TándemAsunto(s)
Antibacterianos/administración & dosificación , Antibacterianos/efectos adversos , Citrus sinensis/microbiología , Productos Agrícolas/microbiología , Residuos de Medicamentos/efectos adversos , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/terapia , Animales , Antibacterianos/análisis , Antibacterianos/farmacología , Aspergilosis/epidemiología , Citrus sinensis/efectos de los fármacos , Productos Agrícolas/efectos de los fármacos , Residuos de Medicamentos/análisis , Farmacorresistencia Microbiana/efectos de los fármacos , Monitoreo del Ambiente , Agricultores , Florida/epidemiología , Humanos , Insectos Vectores/efectos de los fármacos , Oxitetraciclina/administración & dosificación , Oxitetraciclina/análisis , Oxitetraciclina/farmacología , Enfermedades de las Plantas/prevención & control , Evaluación de Programas y Proyectos de Salud , Medición de Riesgo , Estreptomicina/administración & dosificación , Estreptomicina/análisis , Estreptomicina/farmacología , Estados Unidos , United States Environmental Protection Agency/legislación & jurisprudenciaRESUMEN
An electrochemical method is described for the determination of streptomycin (STR). It is making use of a gold electrode coated with a thin mesoporous silica film (MSF). In addition, silver nanoparticles were coated on the MSF to increase the surface area, to bind a large amount of aptamer (Apt), and to improve the electrical conductivity. In the presence of STR, it will bind to the Apt and hinder the diffusion of the redox probe hexacyanoferrate through the nanochannels of the mesoporous film. The aptasensor, best operated at a working potential of 0.22 V (vs. Ag/AgCl) has a linear response in the 1 fg.mL-1 to 6.2 ng.mL-1 STR concentration range. The detection limit is 0.33 fg.mL-1. The assay was successfully validated by analyzing spiked samples of milk and blood serum. Graphical abstract Voltammetric assay of streptomycin (STR) by using a Fe(CN)63-/4- probe. The aptamer was immobilized on a gold electrode modified with a mesoporous silica thin film (MSF) that was functionalized with (3-aminopropyl) triethoxysilane (APTES) and silver nanoparticles (AgNP). Incubation with STR leads to a decrease of the current.
Asunto(s)
Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Técnicas Biosensibles/instrumentación , Oro/química , Nanopartículas del Metal/química , Dióxido de Silicio/química , Estreptomicina/análisis , Aptámeros de Nucleótidos/genética , Secuencia de Bases , Electroquímica , Electrodos , Humanos , Porosidad , Estreptomicina/sangre , Estreptomicina/metabolismoRESUMEN
The authors describe an ultrasensitive method for simultaneous detection of neomycin (NEO) and quinolones antibiotics (QNS). It is based on the use of (a) two immuno-nanoprobes (a probe for NEO and a probe for QNS), (b) surface-enhanced Raman scattering (SERS) detection, and (c), a portable lateral flow assay (LFA). The two probes consist of gold nanoparticles (AuNPs) conjugated to the Raman active molecule 4-aminothiophenol (PATP), and to monoclonal antibody against NEO (NEO mAb) or against NOR (NOR mAb). Quantitative detection of NEO and QNS was realized via SERS of the PATP-coated AuNPs captured in the test line of a LFA. Under optimized condition, the visual limits of LFA are 10 ng·mL-1 for NEO and 200 ng·mL-1 for NOR, and with LODs down to 0.37 pg·mL-1 and 0.55 pg·mL-1 by using SERS. The NEO test line is not interfered by the NEO analogues gentamycin, streptomycin and tobramycin, but the NOR test line suffers from different degrees of cross-reactivity (CR) to 12 common other QNS, the CRs ranging from 1.5% to 136%. The recoveries of NEO and NOR from spiked milk samples ranged between 86% and 121%, with relative standard deviations (RSD) from 3% to 6%. The method is highly sensitive, accurate and effective. It may be applied to simultaneous detection of NEO and 8 QNS, including NOR, enoxacin, ciprofloxacin, ofloxacin, fleroxacin, marbofloxacin, enrofloxacin, and pefloxacin. Graphical abstract Schematic of a lateral flow assay (LFA) based on an indirect competitive model. By using two test lines, the LFA can detect the neomycin and quinolones antibiotics simultaneously. Based on the surface-enhanced Raman scattering (SERS), the LFA shows high sensitivity to antibiotics with low limit of detection.
Asunto(s)
Antibacterianos/análisis , Anticuerpos Monoclonales/química , Bioensayo/métodos , Nanopartículas del Metal/química , Neomicina/análisis , Quinolonas/análisis , Espectrometría Raman/métodos , Antibacterianos/inmunología , Técnicas Biosensibles/métodos , Medios de Contraste/química , Gentamicinas/análisis , Oro/química , Límite de Detección , Neomicina/inmunología , Tamaño de la Partícula , Quinolonas/inmunología , Sensibilidad y Especificidad , Estreptomicina/análisis , Propiedades de Superficie , Tobramicina/análisisRESUMEN
A streptomycin-specific aptamer was used as a receptor molecule for ultrasensitive quantitation of streptomycin. The glassy carbon (GC) electrode was modified with palladium nanoparticles decorated on chitosan-carbon nanotube (PdNPs/CNT/Chi) and aminated aptamer against streptomycin. Modification of the sensing interface was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDS), wavelength-dispersive X-ray spectroscopy (WDX), cyclic voltammetry (CVs), and electrochemical impedance spectroscopy (EIS). The methodologies applied for designing the proposed biosensor are based on target-induced conformational changes of streptomycin-specific aptamer, leading to detectable signal change. Sensing experiments were performed in the streptomycin concentration range from 0.1 to 1500â¯nM in order to evaluate the sensor response as a function of streptomycin concentration. Based on the results, the charge transfer resistance (Rct) values increased proportionally to enhanced streptomycin content. The limit of detection was found to be as low as 18 pM. The superior selectivity and affinity of aptamer/PdNPs/CNT/Chi modified electrode for streptomycin recognition made it favorable for versatile applications such as streptomycin analysis in real samples.