MIP-based extraction techniques for the determination of antibiotic residues in edible meat samples: Design, performance & recent developments

Bioinspired synergy strategy based on the integration of nanozyme into a molecularly imprinted polymer for improved enzyme catalytic mimicry and selective biosensing

Nanozymes offer many advantages such as good stability and high catalytic activity, but their selectivity is lower than that of enzymes. This is because most of enzymes have a protein component (apoenzyme) for substrate affinity to enhance selectivity and a non-protein element (coenzyme) for catalytic activity to improve sensitivity. The synergy between molecularly imprinted polymers (MIPs) and nanozymes can mimic natural enzymes, with MIP acting as the apoenzyme and nanozyme as the coenzyme. Despite researchers' attempts to associate MIPs with nanozymes, the full potential of this combination remains not well explored. This study addresses this gap by integrating Fe3O4-Lys-Cu nanozymes with peroxidase-like catalytic activities within appropriate MIPs for L-DOPA and dopamine. The catalytic performance of the nanozyme was improved by the presence of Cu in Fe3O4-Lys-Cu and further enhanced by MIP. Indeed, the exploration of the pre-concentration property of MIP has increased twenty-fold the catalytic activity of the nanozyme. Moreover, this synergistic combination facilitated the template removal process during MIP production by reducing the extraction time from several hours to just 1 min thanks to the addition of co-substrates which trigger the reaction with nanozyme and release the template. Overall, the synergistic combination of MIPs and nanozymes offers a promising avenue for the design of artificial enzymes.

Current Trends in Nanomaterials-Based Electrochemiluminescence Aptasensors for the Determination of Antibiotic Residues in Foodstuffs: A Comprehensive Review

Veterinary pharmaceuticals have been recently recognized as newly emerging environmental contaminants. Indeed, because of their uncontrolled or overused disposal, we are now facing undesirable amounts of these constituents in foodstuff and its related human health concerns. In this context, developing a well-organized environmental and foodstuff screening toward antibiotic levels is of paramount importance to ensure the safety of food products as well as human health. In this case, with the development and progress of electric/photo detecting, nanomaterials, and nucleic acid aptamer technology, their incorporation-driven evolving electrochemiluminescence aptasensing strategy has presented the hopeful potentials in identifying the residual amounts of different antibiotics toward sensitivity, economy, and practicality. In this context, we reviewed the up-to-date development of ECL aptasensors with aptamers as recognition elements and nanomaterials as the active elements for quantitative sensing the residual antibiotics in foodstuff and agriculture-related matrices, dissected the unavoidable challenges, and debated the upcoming prospects.

Off-line magnetic Fe3O4@SiO2@MIPs-based solid phase dispersion extraction coupling with HPLC for the simultaneous determination of olaquindox and its metabolite in fish muscle and milk samples

An innovative core-shell magnetic molecularly imprinted polymers, Fe₃O₄@SiO₂@MIPs, was elaborately tailored for specific separation and enrichment of olaquindox (OLA) and its metabolic marker methyl-3-quinoxaline-2carboxylic acid (MQCA). Herein, benefiting from the combination of functionalized magnetic nanoparticles (Fe₃O₄@SiO₂) and MIPs, Fe₃O₄@SiO₂@MIPs not only possessed favorable magnetic properties and stability, avoiding tedious sample pretreatment process, but also demonstrated exceptional selective recognition ability and adsorption capacity, suppressing influence of coexisting interfering substances. Encouraged by prominent merits, Fe₃O₄@SiO₂@MIPs-based magnetic solid phase extraction with HPLC method was developed, realizing simultaneous measurement of OLA and MQCA. Under optimal conditions, excellent linear ranges of 0-100 μg/L with detection limit of 0.175-0.271 μg/L were obtained. The proposed method was finally utilized for determination of OLA and MQCA in fish muscle and milk samples with satisfactory recoveries (80.56-95.26%) and relative standard deviation below 8.1%, furnishing a reliable and sensitive strategy for enrichment and detection residual veterinary drugs in food samples.

Electrochemical Aptasensors for Antibiotics Detection: Recent Achievements and Applications for Monitoring Food Safety

Antibiotics are often used in human and veterinary medicine for the treatment of bacterial diseases. However, extensive use of antibiotics in agriculture can result in the contamination of common food staples such as milk. Consumption of contaminated products can cause serious illness and a rise in antibiotic resistance. Conventional methods of antibiotics detection such are microbiological assays chromatographic and mass spectroscopy methods are sensitive; however, they require qualified personnel, expensive instruments, and sample pretreatment. Biosensor technology can overcome these drawbacks. This review is focused on the recent achievements in the electrochemical biosensors based on nucleic acid aptamers for antibiotic detection. A brief explanation of conventional methods of antibiotic detection is also provided. The methods of the aptamer selection are explained, together with the approach used for the improvement of aptamer affinity by post-SELEX modification and computer modeling. The substantial focus of this review is on the explanation of the principles of the electrochemical detection of antibiotics by aptasensors and on recent achievements in the development of electrochemical aptasensors. The current trends and problems in practical applications of aptasensors are also discussed.