Electrospun Nylon Fibers with Integrated Polypyrrole Molecularly Imprinted Polymers for the Detection of Glucose

Abstract

Electrospun nylon 6,6 fibers incorporating polypyrrole (PPy) molecular-imprinted polymers (MIPs) were produced for the selective detection of D-glucose using a thermal detection methodology. PPy MIPs were produced using a facile bulk synthesis approach and electrospun into intricate fibrous scaffolds giving a highly mass-producible sensing interface. The maximum incorporation of MIPs and greatest sensing performance was found to be 12.1 wt % in conjunction with the heat-transfer method (HTM), a low-cost and simple thermal detection method that measures changes in the thermal resistance at the solid−liquid interface. It is demonstrated that a 12.1% incorporation of MIPs into electrospun fibers produces the widest working linear range with a limit of detection of 0.10 ± 0.01 mM. There were no observed changes in the measured thermal resistance response to incubation with a series of structurally similar compounds, providing evidence toward the selectivity of the platform. Additionally, the sensing platform exhibited a linear working response to glucose samples in artificial sweat solutions in the biologically relevant range. This is the first report of the incorporation of MIPs into nylon 6,6 fibers for the detection of glucose and points toward the possibility of developing mass-producible electrospun fibers embedded with low-cost recognition elements of improved thermal and chemical stability for the application of wearable sensor technology.

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

“…The reason for taking the error on the measurement signal (intra-sample variability) rather than the standard error on the average of three measurements (inter-sample variability) is that the former is bigger than the latter. While this shows the sensitivity limitations of the low-cost readout technology, it also demonstrates that the electrode production process is highly reproducible and leads to a high degree of repeatability in the resulting sensor platform. − This y-value was then plotted and its intercept with the black curve was the calculated LoD for the sensor being 19.4 μM. The calculated intercept for the LoD (19.4 μM) is greater than the curve plotted for the NIP data, demonstrating that the sensor is capable of detecting concentrations of glucose that bind specifically.…”

“…The HTM is a novel and innovative thermal sensing readout platform developed over the course of last 10 years . The method has received increasing attention in the last few years and has recently been applied in the detection of bacteria and small molecules via the use of surface-imprinted polymers , and MIPs. − In essence, the method is capable of measuring the thermal resistance across a liquid–solid phase boundary, with MIPs being the receptor layer deposited between the two. As a target analyte is introduced in the liquid phase, it binds to the deposited MIPs, changing its thermodynamic properties, leading to a change in the thermal conduction path between the liquid phase and the solid phase (Figure ).…”

Electrospun nanofiber-based glucose sensors for glucose detection

“…In the MIP glucose sensor, the MIP with catalytic and conductive properties are obtained by wrapping the GOx into the conductive polymer. Crapnell et al (2021) prepared a glucose sensor of electrospun nylon 6,6 fibers containing PPy MIPs. Added PPy MIPs in nylon 6,6 solutions were prepared as the electrospinning solutions.…”

A flexible electrochemical glucose sensing platform based on an electrospun PVA mat covered with in situ grown silver nanoparticles and a mixed self-assembled monolayer of glucose oxidase and ferrocene

“…9–12 As a flexible film production technology, electrospinning provides a practical and low-cost way to fabricate textile-like films with ultrathin fibers having applications in glucose sensing. 13–17…”

“…[9][10][11][12] As a flexible film production technology, electrospinning provides a practical and low-cost way to fabricate textile-like films with ultrathin fibers having applications in glucose sensing. [13][14][15][16][17] While GOD is commonly employed in the construction of enzymatic glucose sensing interfaces due to its cost-effectiveness and stability, 18 it is important to note that the presence of oxygen can adversely affect the performance of enzymatic electrochemical glucose biosensors, which could be particularly pronounced in non-invasive flexible sensors that are attached to the skin. 19,20 Therefore, in many cases, introducing specific redox mediators into enzyme-based detection systems is an effective and necessary strategy that could facilitate electron transfer between enzymes and electrodes and make it possible to avoid oxygen reduction potential during detection.…”