Screen Printed Electrode Based Detection Systems for the Antibiotic Amoxicillin in Aqueous Samples Utilising Molecularly Imprinted Polymers as Synthetic Receptors

Abstract

Molecularly Imprinted Polymers (MIPs) were synthesised for the selective detection of amoxicillin in aqueous samples. Different functional monomers were tested to determine the optimal composition via batch rebinding experiments. Two different sensor platforms were tested using the same MIP solution; one being bulk synthesized and surface modified Screen Printed Electrodes (SPEs) via drop casting the microparticles onto the electrode surface and the other being UV polymerized directly onto the SPE surface in the form of a thin film. The sensors were used to measure amoxicillin in conjunction with the Heat-Transfer Method (HTM), a low-cost and simple thermal detection method that is based on differences in the thermal resistance at the solid–liquid interface. It was demonstrated that both sensor platforms could detect amoxicillin in the relevant concentration range with Limits of Detection (LOD) of 1.89 ± 1.03 nM and 0.54 ± 0.10 nM for the drop cast and direct polymerisation methods respectively. The sensor platform utilising direct UV polymerisation exhibited an enhanced response for amoxicillin detection, a reduced sensor preparation time and the selectivity of the platform was proven through the addition of nafcillin, a pharmacophore of similar shape and size. The use of MIP-modified SPEs combined with thermal detection provides sensors that can be used for fast and low-cost detection of analytes on-site, which holds great potential for contaminants in environmental aqueous samples. The platform and synthesis methods are generic and by adapting the MIP layer it is possible to expand this sensor platform to a variety of relevant targets.

Dual detection of nafcillin using a molecularly imprinted polymer-based platform coupled to thermal and fluorescence read-out

“…It was noted, however, that the observed increase was smaller than expected based on previous measurements with MIPs and HTM, with an R th increase of 0.5 ºC/W obtained in the nM range 37 . One possible explanation was the total mass of polymer on the glass substrates.…”

“…Therefore, it would be highly expensive and inefficient to have a more complex fluorophore present in each site. We compare the performance of fluorescent MIPs in the form of 6 microparticles and thin films in terms of rebinding capacity 37 , and fluorescent response in the presence of the target. Within this analysis, we explore and optimise the procedure for producing MIPs as thin films in a reproducible and consistent manner.…”

Colorimetric Sensing of Amoxicillin Facilitated by Molecularly Imprinted Polymers

“…These results are, however, surprising when comparing the data to the literature, as research found on the development of MIPs towards amoxicillin suggests that acrylamide provides the better binding solution [ 42 ]. However, the two acrylamide based MIPs tested in the research outline performed extremely poor when compared to that of the MAA-based MIPs.…”

“…The component ratios used for the MIPs synthesized were based on previous literature regarding the monolithic polymerization of molecularly imprinted polymers [ 42 ]. In general, functional monomer (1.4 mmol), template (0.35 mmol), crosslinker (2.8 mmol), and DMSO (3.3 mL) were placed in a glass vial and dissolved O 2 purged from the mixture by bubbling N 2 through the solution for 30 s. AIBN (36.1 mg, 0.22 mmol) was then added to the resulting mixture, ensuring that the solution was thoroughly mixed before subjecting the solution to a UV lamp (BlueWave 200, wavelength: 300–450 nm), thus initiating polymerization under photochemical conditions.…”

The Use of Aptamers and Molecularly Imprinted Polymers in Biosensors for Environmental Monitoring: A Tale of Two Receptors

“…For example, in 2015, researchers demonstrated the detection of tetracycline while using a simple triple helix molecular switch for the detection of tetracycline in tap water, achieving a detection limit of 2.09 nM [52]. In addition to tetracycline based antibiotics, aptamers and MIP based sensors have both been developed for other types of antibiotics, such as amoxicillin [53,54]. In the case of kanamycin, Geng et al even demonstrated the synergistic combination of MIPs and aptamers for the detection of kanamycin while using fluorescence quenching [55].…”