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

Abstract

Glucose bio-sensing technologies have received increasing attention in the last few decades, primarily due to the fundamental role that glucose metabolism plays in diseases (e.g., diabetes). Molecularly imprinted polymers (MIPs) could offer an alternative means of analysis to a field that is traditionally dominated by enzyme-based devices, posing superior chemical stability, cost-effectiveness, and ease of fabrication. Their integration into sensing devices as recognition elements has been extensively studied with different readout methods such as quartz-crystal microbalance or impedance spectroscopy. In this work, a dummy imprinting approach is introduced, describing the synthesis and optimization of a MIP toward the sensing of glucose. Integration of this polymer into a thermally conductive receptor layer was achieved by micro-contact deposition. In essence, the MIP particles are pressed into a polyvinyl chloride adhesive layer using a polydimethylsiloxane stamp. The prepared layer is then evaluated with the so-called heat-transfer method, allowing the determination of the specificity and the sensitivity of the receptor layer. Furthermore, the selectivity was assessed by analyzing the thermal response after infusion with increasing concentrations of different saccharide analogues in phosphate-buffered saline (PBS). The obtained results show a linear range of the sensor of 0.0194–0.3300 mM for the detection of glucose in PBS. Finally, a potential application of the sensor was demonstrated by exposing the receptor layer to increasing concentrations of glucose in human urine samples, demonstrating a linear range of 0.0444–0.3300 mM. The results obtained in this paper highlight the applicability of the sensor both in terms of non-invasive glucose monitoring and for the analysis of food samples.

Progress of Polyaniline Glucose Sensors for Diabetes Mellitus Management Utilizing Enzymatic and Non-Enzymatic Detection

“…The direct electrocatalytic oxidation of glucose occurs on the electrode surface to avoid deficiencies that originate in the nature of enzymes. A wide variety of materials have been utilized in non-enzymatic glucose sensors, e.g., CPs [11,12], multiwalled carbon nanotubes (MWCNT) [9,13], and molecularly imprinted polymers (MIPs) [26,27], which can mimic enzymes by creating crosslinked polymeric active sites for specific analytes.…”

A Molecularly Imprinted Polymer-Based Thermal Sensor for the Selective Detection of Melamine in Milk Samples

“…The temperature profiles over time were used to construct dose–response curves for both MIP and NIP by plotting the different concentrations of melamine injected against the effect size as a function of the temperature change. The effect size was calculated using the same equation reported in previous work [ 39 ] (Equation (1)). …”

“…The MIP-based receptor layer was prepared according to previous literature, with slight modifications [ 39 ]. First, a polyvinyl chloride (PVC) adhesive layer was deposited on the aluminum chip by spin coating (1000 rpm for 60 s with an acceleration of 1000 rpm s −1 ) a 2.0 wt% PVC solution in tetrahydrofuran.…”

Synthesis and potential applications of trimetallic nanostructures

“…192 For example, the design of a reliable, fast, and cost-effective glucose sensor to determine and control diabetes. 193 To date, many efforts have been made to develop electrochemical immunosensors for biological detection, food safety, environmental pollution monitoring, etc. AgPtCo nanodendrites (NDs) have been used as an electrochemical biosensor for human epididymis protein 4 (HE4) assays with a minimum detectable concentration of 0.487 pg mL À1 .…”