Ampicillin In Milk Research Articles

Click chemistry-based fluorescence polarization sensor for sensitive detection of ampicillin

Ampicillin (AMP) is a β-lactam antibiotic that can inhibit bacterial wall synthesis. The overuse and misuse of AMP makes it micropollutant that commonly found in food and various environmental media. In this work, a fluorescence polarization sensor was designed to sensitive detection of trace ampicillin based on click chemistry, using graphene oxide (GO) as a fluorescence polarization (FP) signal enhancement element. First, when ampicillin binds to its aptamer (apt), the adjacent alkyne and azide groups are separated, hindering the click-linking reaction. When Carboxyfluorescein (FAM) fluorophore-labeled probe (C-FAM) is added, its protruding 3-terminal FAM is recognized and cleaved by exonuclease I (EXO I), releasing fluorophores free that could not be adsorbed on GO, resulting in a lo0wer polarization signal. If there is no AMP in the system, aptamer probe is connected to its complementary chain ends by a click reaction. After C-FAM hybridizes with apt, the apt/P duplex is opened and the prominent single-stranded ends adsorb on the GO, leading a significantly enhanced FP signal. According to the relationship between the difference in FP values and the concentrations of AMP, the limit of detection of proposed method is as low as 80 pg/mL. This assay has a wide linear range plus excellent selectivity, and has been applied to detect AMP in milk and river water samples with satisfactory results, which demonstrates that the FP sensor has great potential for practical applications in food safety and environmental protection fields.

Label-free electrochemical sensing platform for sensitive detection of ampicillin by combining nucleic acid isothermal enzyme-free amplification circuits with CRISPR/Cas12a

The residue of ampicillin (AMP) in food and ecological environment poses a potential harm to human health. Therefore, a reliable system for detecting AMP is in great demand. Herein, a label-free and sensitive electrochemical sensor utilizing NH2–Co-MOF as an electrocatalytic active material for methylene blue (MB) was developed for rapid and facile AMP detection by combining hybridization chain reaction (HCR), catalytic hairpin assembly (CHA) with CRISPR/Cas12a. The surface of glassy carbon electrode modified with NH2–Co-MOF was able to undergo HCR independent of the AMP, forming long dsDNA complexes to load MB, resulting in strong original electrochemical signal. The presence of AMP could trigger upstream CHA circuit to activate the CRISPR/Cas12a system, thereby achieving rapid non-specific cleavage of the trigger ssDNA of HCR on the electrode surface, hindering the occurrence of HCR and reducing the load of MB. Significant signal change triggered by the target was ultimately obtained, thus achieving sensitive detection of the AMP with a detection limit as low as 1.60 pM (S/N = 3). The proposed sensor exhibited good stability, selectivity, and stability, and achieved reliable detection of AMP in milk and livestock wastewater samples, demonstrating its promising application prospects in food safety and environmental monitoring.

Peroxidase-like activity and mechanism of gold nanoparticle-modified Ti3C2 MXenes for the construction of H2O2 and ampicillin colorimetric sensors.

Transition metal carbides modified by Au nanoparticles (Au/Ti3C2) were synthesized and developed as a colorimetric sensor for the determination of H2O2 and ampicillin. The surface electrical properties of Ti3C2 were changed, and Au nanoparticles (AuNPs) and gold growth solution were synthesized simultaneously. Au/Ti3C2 was obtained by seed growth method with AuNPs modified on the surface of transition metal carbides, nitrides or carbon-nitrides (Ti3C2 MXenes). The synthesized AuNPs and Ti3C2 had no peroxidase-like activity, but Au/Ti3C2 had. The peroxidase catalytic mechanism was due to electron transfer. The peroxidase activity of Au/Ti3C2 can be utilized for the determination of H2O2. The linear range of Au/Ti3C2 for H2O2 was 1-60 µM, and the detection limit was 0.12 µM (S/N = 3). A colometric sensor for ampicillin detection based on Au/Ti3C2 was further constructed since S in ampicillin formed an Au-S bond with Au/Ti3C2, leading to the weakening of its peroxidase-like property. The change of peroxidase-like property attenuated oxidation of TMB, and the ampicillin content was inversely proportional to the concentration of oxidized TMB, and the blue color of solution faded, which enabled the determination of ampicillin. The linear range for ampicillin was 0.005-0.5µg mL- 1, and the detection limit was 1.1 ng mL- 1 (S/N = 3). The sensor was applied to the detection of ampicillin in milk and human serum.

Label-free selective and sensitive colorimetric detection of ampicillin in milk and water using silver nanoparticles

Overuse of antibiotics like ampicillin in various developing and industrializing countries leads to the evolution of drug-resistant bacteria and different adverse effects on an individual's health. Though creating a facile, sensitive, and selective method for ampicillin detection is critical, this remains a strategic task. The poly(vinyl alcohol) (PVA)-capped silver nanoparticles (AgNPs) were used to develop a colorimetric assay for the detection of ampicillin. UV-Vis spectroscopy shows a strong peak at 402 nm due to the excitation of surface plasmon resonance (SPR). The X-ray diffraction (XRD) pattern of AgNPs shows lattice planes (111) and (200) correspond to 2θ values of 38.4° and 44.67°, respectively. Transmission electron microscopy (TEM) histogram shows the large number of particles synthesized in the range of 9–13 nm. As-synthesized AgNPs were used to evaluate the selectivity of the assay against various competitive antibiotics. The colour change of the assay mixture from yellow to orange was found in the presence of ampicillin due to target-specific aggregation and localized surface plasmon resonance changed from 402 nm to 550 nm. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 6.2 μM and 18.8 μM (linear range 0.5–10 μM) respectively. The colorimetric assay was used to detect the ampicillin-spiked actual samples (tap water, Yamuna River water, and milk). The developed colorimetric assay provides a real-time, rapid, and easy-to-use platform for detecting ampicillin for real sample analysis.

An aptasensor for ampicillin detection in milk by fluorescence resonance energy transfer between upconversion nanoparticles and Au nanoparticles.

This paper reports a portable fluorescence resonance energy transfer (FRET) aptasensor for ampicillin (Amp) detection using upconversion particles (UCNPs) as energy donors and Au nanoparticles (AuNPs) as energy acceptors. The optimal parameters of the detection system were investigated. Under the optimal conditions, it had a good linear relationship between the fluorescence intensities and Amp concentrations, a high coefficient of determination (R2) of 0.9939, a wide detection range of 10-100ng/mL, and a low limit of detection (LOD) of 3.9ng/mL; meanwhile, the aptasensor had high selectivity for Amp against the interference of other antibiotics, and had good recovery and repeatability. Also, its detection performance had been successfully validated by milk samples. Therefore, the developed aptasensor based on FRET between UCNPs and AuNPs has a good prospect for Amp on-site detection in milk with a portable upconversion detection instrument.

Ultra-sensitive electrochemical detection of ampicillin with hollow tubular mesoporous In2O3@Au@Apta nanofibers as electrode materials

A mesoporous In2O3@Au nanofiber was proposed for the electrochemical aptasensor for the detection of ampicillin (AMP). In this sensor, Au-modified In2O3 (In2O3@Au) was incubated with an aptamer (Apta), and the resulting electrode modification was integrated on the surface of the working electrode. Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS) were used to realize the research of electrode modification and the detection of AMP. According to the detection results of DPV, the current value and the logarithm of the concentration showed an ideal linear relationship. R2 reached as high as 0.9871, and the detection limit was 1 pg/mL. It has good selectivity and cycle stability. Compared with other antibiotics or amino acids, it has higher selectivity for AMP. The proposed In2O3@Au@Apta can effectively and sensitively detect AMP in milk and has broad application prospects.

Magnetic bead-based electrochemical aptasensor doped with multi-wall carbon nanotubes for the detection of ampicillin in milk

Magnetic bead-based electrochemical aptasensor doped with multi-wall carbon nanotubes for the detection of ampicillin in milk

An aptasensor for the detection of ampicillin in milk using a personal glucose meter.

Antibiotic residues in foods have aroused wide public concern because of their potential side-effects. It is imperative to develop a simple, accurate and reliable method for the detection of antibiotic residues in foods. In this paper, we report a novel, facile and sensitive method for the detection of ampicillin in milk using a commercial personal glucose meter (PGM). Magnetic beads (MBs) were employed as the platform, an ampicillin aptamer was used as the recognition element and streptavidin was utilized as the bridge to link invertase and the aptamer. After the hydrolysis of sucrose to glucose, the concentration of glucose was quantitatively measured using the PGM. The difference of PGM signals with and without addition of ampicillin exhibits a good linear correlation with the logarithm of ampicillin concentrations in the range of 2.5 × 10-10 mol L-1 to 1.0 × 10-7 mol L-1 with a detection limit of 2.5 × 10-10 mol L-1 (S/N = 3). Finally, the proposed method was successfully applied for the detection of ampicillin residue in milk.

Detection of low concentrations of ampicillin in milk.

Ampicillin, a common antibiotic, is detected at trace concentrations in milk using surface enhanced Raman spectroscopy in a microfluidic device, using less than 20 μL of sample, in 10 minutes, with minimal off-chip preparation. The device is configured so as to favor the interaction of the analyte with colloidal silver, and the optimization of the aggregation of the silver nanoparticles so as to increase the SERS intensity and the consequential sensitivity of analyte detection.

Research on degradation of penicillins in milk by β-lactamase using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry

The degradation of penicillin G, penicillin V, and ampicillin in milk in the presence of β-lactamase was investigated by ultra-performance liquid chromatography coupled with electrospray ionization-time-of-flight mass spectrometry. Degradation products of the 3 penicillins in milk were identified based on the fact that the metabolites or degradation products contain a substructure of penicillin, and their degradation pathways in acidic milk in presence of β-lactamase were developed. The influence of factors on the degradation was investigated, including β-lactamase dosage, temperature, time, and acidity. The ratio of the 2 degradation products (penicilloic acid and penilloic acid) is different at different temperatures and pH. Penicilloic acid was the dominant species obtained at pH 6 under 40°C, but, being unstable, it could not be used as a standard for accurate analysis of penicilloic acid, and also could not be used as target for detection of penicillins in milk. Penilloic acid was the dominant species obtained at pH 2 above 40°C; it was stable and could be used as a standard for quantitative analysis and as target for detecting whether penicillins were used in milk.

Immunochromatographic technique for express determination of ampicillin in milk and dairy products

An immunochromatographic method for determination of beta-lactam antibiotic ampicillin has been developed. The method is based on the competitive interaction between antibiotic molecules contained in the sample and protein conjugate of penicillin immobilized on a membrane for binding with specific antibodies labeled with colloidal gold, which occurs during movement of the sample to be tested and reagents along the membrane. The completion of the test system ensures control of exceeding the maximum permissible content of the antibiotic in milk and dairy products (10 ng/ml). The possibility of testing milk, raw milk, and dairy products for 10 minutes at room temperature without sample preparation has been demonstrated.

Enzyme-Linked Immunosorbent Assay of Ampicillin in Milk

An indirect immunoassay for quantitative determination of ampicillin (range, 10–1000 ng/ml) in buffer or milk has been developed. Polyclonal antibodies were obtained against ampicillin conjugated with bovine serum albumin; the conjugate was synthesized by direct condensation using carbodiimide. The antibodies were specific for ampicillin and exhibited low cross-reactivity to other penicillins (azlocillin, 17%; penicillin G, 10%; piperacillin, 5%; and carbenicillin, 4%). Matrix effects were minimized by combining the use of a casein-supplemented buffer (content of casein, 1%) with sample dilution. Limit of detection for ampicillin in milk (diluted tenfold) was equal to 5.0 ng/ml (which corresponded to 50 ng/ml of the original sample).

Screening of penicillin residues in milk by a surface plasmon resonance-based biosensor assay: comparison of chemical and enzymatic sample pre-treatment

A biosensor-based immunoassay for the screening of penicillin residues in milk was developed. The BIAcore biosensor which was employed was based on surface plasmon resonance detection. One commercial antibody against ampicillin which had much higher affinity for open beta-lactam ring than for closed ring was chosen. Two different pre-treatments were tested prior to the biosensor assay to open the ring in order to increase the assay sensitivity. These two ways were enzymatic (penicillinase) and chemical pre-treatment of the samples. Limits of detection for ampicillin in milk were 33 and 12.5 μg l −1 after enzymatic and chemical pre-treatment, respectively. There were no cross-reactions with cephalosporins and other families of antibiotics or proteins in the buffer and in milk after both the pre-treatments. Percentages of cross-reactivity with nine tested penicillins were often clearly higher in milk than in buffer. Moreover, a lack of sensitivity after penicillinase pre-treatment was observed. Conversely, penicillins G and penicillins M could be detected at or below their respective MRLs (4 and 30 μg l −1 in milk) and ampicillin and amoxicillin could be detected only at about three MRLs after chemical pre-treatment. However, the enzymatic pre-treatment was much easier to perform and led to more stable results.

Ampicillin and amoxicillin residue detection in milk, using microbial receptor assay (Charm II) and liquid chromatography methods, after extra-label administration of the drugs to lactating cows

Abstract Objective A microbial receptor assay method (MRAM; Charm II test) for β-lactam antibiotics and a liquid chromatography (LC) method with a detection limit of 2 to 5 ppb were evaluated for detection of ampicillin or amoxicillin residues in milk samples from individuell cows. Design The MRAM was compared to the LC in 2 respects. Measured concentrations of drugs were compared, as well as the classification of samples relative to the FDA tolerance value of 10 ppb. Animals A total of 6 clinically normal lactating Holstein cows were used per drug. Procedure Ampicillin trihydrate or amoxicillin trihydrate was administered at an extra-label dosage of 22 mg/kg of body weight, IM, once to each of 6 cows/drug. Milk samples were collected at milkings prior to and for 156 hours after drug administration. Drug concentrations in milk samples from individual cows were determined by use of the MRAM and LC tests. Additionally, the classification of milk samples relative to the presence or absence of residues above the FDA tolerance value was determined. Pharmacokinetic analysis was performed on derived milk drug concentrations. Results Concentration of ampicillin in milk samples from all cows was < 10 ppb by the MRAM and LC methods by the fourth milking (48 hours) after treatment with ampicillin. Values were < 10 ppb by both methods for all cows treated with amoxicillin by the sixth milking (72 hours) after treatment. For individual milk samples, significant differences were found between test methods in the proportion of positive (failing) tests; the MRAM had a higher proportion of presumptive positives. Conclusions Even at an extra-label dosage of 22 mg/kg, IM, milk residues > 10 ppb (the FDA tolerance value) were not detected beyond the label milk withholding times for ampicillin (48 hours) and amoxicillin (96 hours). When used for testing milk of individual cows by the control point procedure, the MRAM had a tendency to give presumptive positive test results for milk samples containing < 10 ppb ampicillin or amoxicillin as determined by LC. (Am J Vet Res 1996;57:73-78)

Studies on residual antibacterials in foods : IV. Simultaneous determination of penicillin G, penicillin V and ampicillin in milk by high-performance liquid chromatography

A rapid and simple method for the simultaneous determination of penicillin G (PCG), penicillin V (PCV) and ampicillin (ABPC) in milk is described. The retention behaviour of these β-lactam antibiotics in reversed-phase liquid chromatography with mobile phases containing sodium alkylsulphonate was studied. Good separations were obtained with methanol—water—0.2 M phosphate buffer (pH 4.0) (5:13:2) containing 11 m M sodium 1-heptanesulphonate and a LiChrosorb RP-18 column. The sample was pre-treated with a Sep-Pak C 8 cartridge. The peaks corresponding to each β-lactam antibiotics can be confirmed with the treatment using penicillinase. The recoveries from milk fortified with sodium PCG, potassium PCV and ABCP at levels of 0.5 and 0.1 μg/g each were generally better than 87% and the relative standard deviations were 1.17–4.98%. The detection limits correspond to 0.03 μg/g of these β-lactam antibiotics in milk.

Detection of Residual penicillin in milk by sensitive enzyme immunoassay.

A convenient and precise method by an application of a highly sensitive enzyme immunoassay of penicillin to detect the veterinary penicillin residue in milk was studied. The procedures of the assay to detect more than 0.01 microgram/ml of ampicillin in milk were developed. Five commercial milk samples were tested by the assay procedure, and no veterinary ampicillin residue was detected in any of them.