Colorimetric Sensing of Amoxicillin Facilitated by Molecularly Imprinted Polymers

Abstract

The scope of the presented research orientates itself towards the development of a Molecularly Imprinted Polymer (MIP)-based dye displacement assay for the colorimetric detection of the antibiotic amoxicillin in aqueous medium. With this in mind, the initial development of an MIP capable of such a task sets focus on monolithic bulk polymerization to assess monomer/crosslinker combinations that have potential towards the binding of amoxicillin. The best performing composition (based on specificity and binding capacity) is utilized in the synthesis of MIP particles by emulsion polymerization, yielding particles that prove to be more homogenous in size and morphology compared to that of the crushed monolithic MIP, which is an essential trait when it comes to the accuracy of the resulting assay. The specificity and selectivity of the emulsion MIP proceeds to be highlighted, demonstrating a higher affinity towards amoxicillin compared to other compounds of the aminopenicillin class (ampicillin and cloxacillin). Conversion of the polymeric receptor is then undertaken, identifying a suitable dye for the displacement assay by means of binding experiments with malachite green, crystal violet, and mordant orange. Once identified, the optimal dye is then loaded onto the synthetic receptor, and the displaceability of the dye deduced by means of a dose response experiment. Alongside the sensitivity, the selectivity of the assay is scrutinized against cloxacillin and ampicillin. Yielding a dye displacement assay that can be used (semi-)quantitatively in a rapid manner.

Thermal Pyocyanin Sensor Based on Molecularly Imprinted Polymers for the Indirect Detection of Pseudomonas aeruginosa

“…After optimizing the synthesis procedure, MIPs made using the best recipe were used to further study rebinding with the heat-transfer method (HTM) in complex samples. The thermal transducer principle has been extensively studied for a wide range of targets, as described in previous works of our research group. ,, In short, the HTM technology measures the heat transfer over a MIP-covered aluminum chip, positioned in between a copper block and a polycarbonate flow cell ( A = 28 mm 2 , V = 110 μL). The function of the copper block is to transfer the heat generated by a power resistor, to the bottom side of the MIP-covered chips.…”

“…To overcome this, a low-cost and straightforward alternative transducer principle, coined the heat-transfer method (HTM), was introduced by the authors in 2012 . This sensing technique offers the possibility to study the selectivity and sensitivity of receptor layers (e.g., MIPs) for the desired target by simply studying the heat transport over a functional layer. − The HTM has been successfully combined with synthetic receptors to detect a wide array of targets, ranging from small molecules to larger biological entities. − Bacteria detection is a particularly interesting application, but it requires the use of bacteria cells as templates to create synthetic receptors. , This limits the scalability of the receptor synthesis and increases the measurement cost significantly.…”

Thermal Detection of Glucose in Urine Using a Molecularly Imprinted Polymer as a Recognition Element

“…Dummy MIPs were synthesized accordingly to a previously described procedure. , In essence, functional monomer (AAM, 2 mmol, 142 mg), template ( d -glucuronic acid, 0.25 mmol, 48.5 mg), crosslinker (EGDMA, 3 mmol, 566 μL), and thermal initiator (AIBN, 0.25 mmol, 40 mg) were dissolved in 3 mL of dimethyl sulfoxide (DMSO). The mixture was then purged with N 2 to remove any oxygen from the mixture before the initiation of polymerization.…”

State‐of‐the‐art molecular imprinted colorimetric sensors and their on‐site inspecting applications

“…Lowdon et al. developed an MIP‐based dye substitution method for the colorimetric detection of antibiotic amoxicillin in water media [38]. Good detection results can be obtained by selecting appropriate dyes.…”

“…Considering the overuse, antibiotics have become one of the world's biggest environmental pollutants. Lowdon et al developed an MIP-based dye substitution method for the colorimetric detection of antibiotic amoxicillin in water media [38]. Good detection results can be obtained by selecting appropriate dyes.…”