Development and application of one-step ELISA for the detection of neomycin in milk

Affinity-Based Analysis Methods for the Detection of Aminoglycoside Antibiotic Residues in Animal-Derived Foods: A Review

With the increasingly serious problem of aminoglycoside antibiotic residues, it is imperative to develop rapid, sensitive and efficient detection methods. This article reviews the detection methods of aminoglycoside antibiotics in animal-derived foods, including enzyme-linked immunosorbent assay, fluorescent immunoassay, chemical immunoassay, affinity sensing assay, lateral flow immunochromatography and molecular imprinted immunoassay. After evaluating the performance of these methods, the advantages and disadvantages were analyzed and compared. Furthermore, development prospects and research trends were proposed and summarized. This review can serve as a basis for further research and provide helpful references and new insights for the analysis of aminoglycoside residues. Accordingly, the in-depth investigation and analysis will certainly make great contributions to food safety, public hygiene and human health.

Toward Rapid and Automated Immunoassays: Using a Localized Electrochemical pH Modulation Platform to Perform a Single-Step Immunoassay

An electrochemical platform for generating and controlling a localized pH microenvironment on demand is proposed by employing a closed-loop control algorithm based on an iridium oxide pH sensor input. We use a combination of solution-borne quinones and galvanostatic excitation on a prepatterned indium tin oxide (ITO) working electrode to modulate pH within a very well confined, small volume of solution close to the electrode surface. We demonstrate that the rate of pH change can be controlled at up to 2 pH s^-1 with an excellent repeatability (±0.004). The desired pH microenvironment can be stably maintained for longer than 2 h within ±0.0012 pH. As a high-impact application of the platform technology, we propose a single-step immunoassay and demonstrate its utility in measuring C-reactive protein (CRP), a critical inflammatory marker in various conditions such as myocardial infarction and even SARS-Cov-2. Utilizing pH modulation technology along with pH-sensitive fluorescence dye simplifies the immunoassay process into a single-step, where a mixture of all of the reagents is incubated only for 1 h without any washing steps or the need to change solution. This simplified immunoassay process minimizes the hands-on time of the end-user and thus decreases technician-driven errors. Moreover, the absence of complicated liquid-handling hardware makes it more suitable and attractive for an ultracompact platform to ultimately be used in a point-of-care diagnostic assay.

Evaluating the immunogenicity of gold nanoparticles conjugated RBD with Freund's adjuvant as a potential vaccine against SARS-CoV-2

BACKGROUND

and Introduction: SARS-CoV-2 is currently considered as the most challenging issue in the field of health and medicine by causing a global pandemic. Vaccines are counted as a promising candidate to terminate this deadly pandemic. Various structural proteins in SARS-CoV-2 have recently drawn attention to be utilized as candidate vaccines to stimulate immune responses against COVID-19.

MATERIALS AND METHODS

In current study, the RBD protein was cloned and expressed in E. coli host. Then, the expressed RBD protein was purified and its characterizations were evaluated through various methods. Gold nanoparticles, which were utilized as a carrier for candidate Nano-vaccine, were synthesized via oxidation-reduction reaction. While Gold NPs-conjugated RBD was injected into the second treatment group, in the first candidate vaccine, RBD was injected into the first treatment group solely. Complete and Incomplete Freud's Adjuvant were also utilized for both treatment groups to enhance the immune responses against RBD antigen. Immunizations were repeated 2 times in 14-day intervals to boost the immune system of BALB/c mice. The humoral and cell-mediated immune responses were examined through immune and cytokine assays.

RESULTS

Our outcomes demonstrate that strong short-term humoral immunity (IgM) was induced in both the first and second treatment group, while long-term humoral responses (IgG) were only observed in the second treatment group. While stronger short- and long-term humoral (IgM and IgG, respectively) were observed in the second treatment group, particular cytokines production (TNF-ɑ and IFN-γ) as a marker of cell-mediated responses were significantly higher in the first treatment group.

DISCUSSION AND CONCLUSION

Our study results show the high potentiality of RBD protein as an appropriate stimulating antigen in vaccine synthesis and testifies RBD-based candidate vaccines to control the COVID-19 pandemic. Our outcomes also recommend that Nano-vaccines can be more suitable candidates when stronger long-term immune responses matter.

Histidine Functionalized Gold Nanoparticles for Screening Aminoglycosides and Nanomolar Level Detection of Streptomycin in Water, Milk, and Whey

Aminoglycoside (AMG) antibiotics are being applied to treat infections caused by Gram-negative bacteria, mainly in livestock, and are prescribed only in severe cases because of their adverse impacts on human health and the environment. Monitoring antibiotic residues in dairy products relies on the accessibility of portable and efficient analytical techniques. Presently, high-throughput screening techniques have been proposed to detect several antimicrobial drugs having identical structural and functional features. The L-histidine functionalized gold nanoparticles (His@AuNPs) do not form a complex with other tested antibiotic classes but show high selectivity for AMG antibiotics. We used ligand-induced aggregation of His@AuNPs as a rapid and sensitive localized surface plasmon resonance (LSPR) assay for AMG antibiotics, producing longitudinal extinction shifts at 660 nm. Herein, we explore the practical application of His@AuNPs to detect streptomycin spiked in water, milk, and whey fraction of milk with nanomolar level sensitivity. The ability of the analytical method to recognize target analytes sensitively and rapidly is of great significance to perform monitoring, thus would certainly reassure widespread use of AMG antibiotics. The biosynthesis of hybrid organic–inorganic metal nanoparticles like His@AuNPs with desired size distribution, stability, and specific host–guest recognition proficiency, would further facilitate applications in various other fields.

Aggregation-based fluorescence amplification strategy: "turn-on" sensing of aminoglycosides using near-IR carbocyanine dyes and pre-micellar surfactants

This study is aimed at developing sensing schemes without obtaining selective receptors. A series of simple carbocyanine dyes was synthesized, whose emission was quenched in water with formation of nanoparticles in the range of 20-100 nm. Fluorescence in near-IR region is "turned on" in the presence of a drug cation of middle molecular weight (400-700 Da) and sodium dodecyl sulfate (SDS), as well as anionic drugs and a cationic surfactant (cetyltrimethylammonium bromide, CTAB). Aggregates (clusters) up to 100-200 nm in size were detected using dynamic light scattering (DLS) and Rayleigh light scattering (RLS) techniques in the systems: cationic analyte-SDS, carbocyanine dye-CTAB, and in all brightly fluorescent ternary systems dye-surfactant-analyte. Small ions (<200 Da) incapable of multi-point binding do not form the aggregates or cause the emission enhancement. The "turn-on" signal is only observed at the surfactant submicellar concentrations insufficient to solubilize the dye nanoparticles. Based on these findings, we suggest a rapid and simple method for the detection of ≥4·10^-5 mol/L of neomycin in urine. The proposed strategy paves the way for developing more selective methods.

Indirect Determination of Amikacin by Gold Nanoparticles as Redox Probe

BACKGROUND

Amikacin is an aminoglycoside antibiotic used for many gram-negative bacterial infections like infections in the urinary tract, infections in brain, lungs and abdomen. Electrochemical determination of amikacin is a challenge in electroanalysis because it shows no voltammetric peak at the surface of bare electrodes.

OBJECTIVE

In this approach, a very simple and easy method for indirect voltammetric determination of amikacin presented in real samples. Gold nanoparticles were electrodeposited at the surface of glassy carbon electrode in constant potential.

METHODS

The effect of several parameters such as time and potential of deposition, pH and scan rates on signal were studied. The cathodic peak current of Au³⁺ decreased with increasing amikacin concentration. Quantitative analysis of amikacin was performed using differential pulse voltammetry by following cathodic peak current of gold ions.

RESULTS

Two dynamic linear ranges of 1.0 × 10^-8-1.0 × 10^-7 M and 5.0 × 10^-7-1.0 × 10^-3 M were obtained and limit of detection was estimated 3.0× 10^-9 M.

CONCLUSION

The method was successfully determined amikacin in pharmaceutical preparation and human serum. The effect of several interference in determination of amikacin was also studied.

Quantification of neomycin in rubella vaccine by off/on metal ion mediated photoluminescence from functionalized graphene quantum dots

The determination of neomycin sulfate was made using photoluminescent amino-functionalized graphene quantum dots (obtained from hydro-exfoliation of a mixture of citric acid and glutathione). From the several ions tested, Fe³⁺ was the best mediator to enable an off/on photoluminescence effect used for quantification. The mediation of Fe³⁺ was found to be crucial as it is responsible for the photoluminescence quenching effect, due to the interaction with quantum dots surface, also having large affinity towards neomycin that removes Fe³⁺ from the surface of GQDs, consequently, promoting restoration of the original nanomaterial photoluminescence. Such signal restoration was proportional to the neomycin sulfate concentration added. The linearized analytical response covered three orders of magnitude (10^-7 to 10^-5 mol L^-1). The proposed method is an alternative to those requiring labor-intensive procedures for chemical the derivatization of neomycin (due to the lack of chromophore groups in aminoglycosides). The method was successfully tested in the analysis of rubella vaccine containing trace residues of neomycin and in pharmaceutical compositions containing neomycin sulfate after solid phase extraction using an aminoglycoside imprinted polymer to improve selectivity in determinations.

Multiplex lateral flow immunoassay for five antibiotics detection based on gold nanoparticle aggregations

A new immunochromatographic assay was developed for the simultaneous screening of five antibiotics that can coexist in milk, namely lincomycin, gentamicin, kanamycin, streptomycin, and neomycin, using five corresponding monoclonal antibodies.

Development of generic immunoassay for the detection of a series of aminoglycosides with 6'-OH group for the treatment of genetic diseases in biological samples

Over the last two decades, a growing number of scientific evidences highlighted the potential therapeutic value of several structures of aminoglycoside antibiotics (including gentamicin and G418) for the treatment of various genetic diseases caused by nonsense mutations. These findings resulted in a fast evolvement of synthetic derivatives of aminoglycosides which were shown to be more target specific and less toxic than the clinically used antibiotics. The emerging progress in drug design and development has necessitated the urge to develop a fast, easy and accurate procedure for the determination of these potential therapeutic agents in various biologically derived matrices. Here we describe the preparation of a generic polyclonal antibody that was used for the development of homologous and heterologous immunoassays for the detection of a wide range of natural and synthetic aminoglycoside derivatives, highlighted today as potential therapeutic agents for the treatment of various genetic diseases. A common two-ring scaffold, NB82, present in the majority of compounds exhibiting potent biological activity, was used as a generic immunization hapten for the immunization of two rabbits. By using a series of chemical steps, NB82 was selectively conjugated via the N-1 position through glutaric acid linker to a carrier protein. Sensitivity (I₅₀) values for the recognition of three representative compounds NB82, NB84 and NB124 were determined to be 10 ± 3 ng mL⁻¹, 0.5 ± 0.04 μg mL⁻¹ and 1 ± 0.12 μg mL⁻¹, respectively. Limits of detection were determined to be 1 ± 0.3 ng mL⁻¹ for NB82, 20 ± 7 ng mL⁻¹ for NB84 and 15 ± 8 ng mL⁻¹ for NB124. The developed assays were further exploited for the in vivo monitoring of the therapeutic compounds in mice serum. Serum experimentations exhibited similar detection limits as observed for the PBS calibration experiments, demonstrating no interference with assays sensitivity, with rather high recovery ratios ranging from 92 to 107% in whole blood samples.