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

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 Cardiac Biomarkers Heart-Fatty Acid Binding Protein and ST2 Using a Molecularly Imprinted Nanoparticle-Based Multiplex Sensor Platform.

This manuscript describes the production of molecularly imprinted polymer nanoparticles (nanoMIPs) for the cardiac biomarkers heart-fatty acid binding protein (H-FABP) and ST2 by solid-phase synthesis, and their use as synthetic antibodies in a multiplexed sensing platform. Analysis by surface plasmon resonance (SPR) shows that the affinity of the nanoMIPs is similar to that of commercially available antibodies. The particles are coated onto the surface of thermocouples and inserted into 3D-printed flow cells of different multiplexed designs. We demonstrate that it is possible to selectively detect both cardiac biomarkers within the physiologically relevant range. Furthermore, the developed sensor platform is the first example of a multiplex format of this thermal analysis technique which enables simultaneous measurements of two different compounds with minimal cross selectivity. The format where three thermocouples are positioned in parallel exhibits the highest sensitivity, which is explained by modeling the heat flow distribution within the flow cell. This design is used in further experiments and proof-of-application of the sensor platform is provided by measuring spiked fetal bovine serum samples. Because of the high selectivity, short measurement time, and low cost of this array format, it provides an interesting alternative to traditional immunoassays. The use of nanoMIPs enables a multimarker strategy, which has the potential to contribute to sustainable healthcare by improving the reliability of cardiac biomarker testing.

3D Printed Graphene Based Energy Storage Devices.

3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices' to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (-0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (-0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised.