The Journal of the Friends' Historical Society vol. 23 No. 3-4

In motion simulation, motion input scaling is often applied to deal with the limited motion envelopes of motion simulators. In this research, the time-varying effects of scaling the lateral specific force up or down during passive curve driving in a car driving simulation are investigated through a simulator experiment. It is concluded that lateral specific force scaling has a time-varying effect on the perceived fidelity of a curve-driving simulation. In particular, motion scaling during a curve entry is found to be less detrimental than motion scaling during a curve's sustained part and during the curve exit.Control & SimulationControl & Operation

Introducing Thermal Wave Transport Analysis (TWTA): A Thermal Technique for Dopamine Detection by Screen-Printed Electrodes Functionalized with Molecularly Imprinted Polymer (MIP) Particles.

A novel procedure is developed for producing bulk modified Molecularly Imprinted Polymer (MIP) screen-printed electrodes (SPEs), which involves the direct mixing of the polymer particles within the screen-printed ink. This allowed reduction of the sample preparation time from 45 min to 1 min, and resulted in higher reproducibility of the electrodes. The samples are measured with a novel detection method, namely, thermal wave transport analysis (TWTA), relying on the analysis of thermal waves through a functional interface. As a first proof-of-principle, MIPs for dopamine are developed and successfully incorporated within a bulk modified MIP SPE. The detection limits of dopamine within buffer solutions for the MIP SPEs are determined via three independent techniques. With cyclic voltammetry this was determined to be 4.7 × 10−6 M, whereas by using the heat-transfer method (HTM) 0.35 × 10−6 M was obtained, and with the novel TWTA concept 0.26 × 10−6 M is possible. This TWTA technique is measured simultaneously with HTM and has the benefits of reducing measurement time to less than 5 min and increasing effect size by nearly a factor of two. The two thermal methods are able to enhance dopamine detection by one order of magnitude compared to the electrochemical method. In previous research, it was not possible to measure neurotransmitters in complex samples with HTM, but with the improved signal-to-noise of TWTA for the first time, spiked dopamine concentrations were determined in a relevant food sample. In summary, novel concepts are presented for both the sensor functionalization side by employing screen-printing technology, and on the sensing side, the novel TWTA thermal technique is reported. The developed bio-sensing platform is cost-effective and suitable for mass-production due to the nature of screen-printing technology, which makes it very interesting for neurotransmitter detection in clinical diagnostic applications

Recent Advances in Electrosynthesized Molecularly Imprinted Polymer Sensing Platforms for Bioanalyte Detection

The accurate detection of biological materials has remained at the forefront of scientific research for decades. This includes the detection of molecules, proteins, and bacteria. Biomimetic sensors look to replicate the sensitive and selective mechanisms that are found in biological systems and incorporate these properties into functional sensing platforms. Molecularly imprinted polymers (MIPs) are synthetic receptors that can form high affinity binding sites complementary to the specific analyte of interest. They utilise the shape, size, and functionality to produce sensitive and selective recognition of target analytes. One route of synthesizing MIPs is through electropolymerization, utilising predominantly constant potential methods or cyclic voltammetry. This methodology allows for the formation of a polymer directly onto the surface of a transducer. The thickness, morphology, and topography of the films can be manipulated specifically for each template. Recently, numerous reviews have been published in the production and sensing applications of MIPs; however, there are few reports on the use of electrosynthesized MIPs (eMIPs). The number of publications and citations utilising eMIPs is increasing each year, with a review produced on the topic in 2012. This review will primarily focus on advancements from 2012 in the use of eMIPs in sensing platforms for the detection of biologically relevant materials, including the development of increased polymer layer dimensions for whole bacteria detection and the use of mixed monomer compositions to increase selectivity toward analytes

Development of a Flexible MIP-Based Biosensor Platform for the Thermal Detection of Neurotransmitters

We have developed high affinity Molecularly Imprinted Polymers (MIPs) for neurotransmitters such as dopamine, noradrenaline and caffeine. These polymer particles are mixed within the bulk of screen-printed ink allowing masss-producible bulk modified MIP Screen-Printed Electrodes (MIP-SPEs) to be realised. We have explored different SPE supporting surfaces, such as polyester, tracing paper and household-printing paper. The performance of those MIP-SPEs is studied using the Heat-Transfer Method (HTM), a patented thermal method. With the combination of screen-printing techniques and thermal detection, it is possible to develop a portable sensor platform that is capable of low-cost and straightforward detection of biomolecules on-site. In the future, this unique sensor architecture holds great promise for the use in biomedical devices

Functionalized screen-printed electrodes for the thermal detection of Escherichia coli in dairy products

Accurate and fast on-site detection of harmful microorganisms in food products is a key preventive step to avoid food-borne illness and product recall. In this study, screen-printed electrodes (SPEs) were functionalized via a facile strategy with surface imprinted polymers (SIPs). The SIP-coated SPEs were used in combination with the heat transfer method (HTM) for the real-time detection of Escherichia coli. The sensor was tested in buffer, with a reproducible and sensitive response that attained a limit of detection of 180 CFU/mL. Furthermore, selectivity was assessed by analyzing the sensor's response to C. sakazakii, K. pneumoniae and S. aureus as analogue strains. Finally, the device was successfully used for the detection of E. coli in spiked milk as proof-of-application, requiring no additional sample preparation. These results suggest the proposed thermal biosensor possesses the potential of becoming a tool for routine, on-site monitoring of E. coli in food safety applications

Thermistors coated with molecularly imprinted nanoparticles for the electrical detection of peptides and proteins

In this communication, molecularly imprinted nanoparticles (nanoMIPs) that are produced by solid-phase synthesis are functionalised onto thermistors via dip-coating. These thermistors are soldered onto a printed-circuit board to facilitate electrical detection. Subsequently, these are inserted into a home-made thermal device that can measure the selective binding of biomolecules to the nanoMIP layer via monitoring the thermal resistance (Rth) at the solid-liquid interface. This thermal analysis technique, referred to as the Heat-Transfer Method, has previously been used for detection of proteins with MIP-based binders. While offering the advantages of low-cost and label free analysis, this method is limited by the high noise on the feedback loop and not being commercially available. These disadvantages can be overcome by the use of thermistors, which offer superior temperature sensitivity compared to thermocouples, and its electrical read-out can be easily integrated into portable devices. To our knowledge, this is the first report where MIPs are directly integrated onto thermistors for detection purposes. Measurements were conducted with an epitope of epidermal growth factor receptor (EGFR) and trypsin, where the electrical resistance was correlated to the biomolecule concentration. For both EGFR and trypsin, an enhanced signal to noise ratio for the electrical measurements was observed compared to previous analysis that was based on thermal resistance. The sensitivity of the sensors in buffered solution was in the nanomolar range, which is compatible with physiologically relevant concentrations. Upon exposure of the nanoMIP for EGFR towards pepsin no significant change in the resistance was yielded, establishing the selectivity of the developed sensor platform. Besides the enhanced sensitivity, the use of thermistors will enable miniaturisation of the device and has potential for in vivo measurements since specified electrochemical measurements are compatible with human use. To highlight the versatility of the nanoMIPs, this work should be extended to a set of biomolecules with various structures, with the possibility of extending this to an array format

Development of a novel flexible polymer-based biosensor platform for the thermal detection of noradrenaline in aqueous solutions

Molecularly Imprinted Polymers (MIPs) are synthesized for the neurotransmitter noradrenaline with the optimal composition and binding conditions being determined via optical batch rebinding experiments. Next, the obtained MIP polymer particles are mixed within screen-printed inks to produce mass-producible bulk modified MIPs screen-printed electrodes (MIP-SPEs). In this contribution, the supporting surface which the MIP-SPEs are screen-printed upon are explored to deviate from conventional polyester, to polyvinylchloride, tracing paper and household-printing paper. The performance of the MIP-SPEs are measured using the Heat-Transfer Method (HTM), a straightforward and low-cost detection technique based on thermal resistance. At first, the noise on the signal is minimized by adjusting the settings of the temperature feedback loop. Second, the response of the MIP-SPEs to noradrenaline is measured and compared for the different substrate materials. Sensors printed onto paper are considered in further experiments as their response to noradrenaline is the highest and advantageous material properties, including sustainability and flexibility of the material. Subsequently, dose-response curves are determined by simultaneously measuring HTM and Thermal Wave Transport Analysis (TWTA). The latter is a new thermal detection method that relies on the use of thermal waves and has the advantage of a short measurement time (2 min). With these thermal methods, it is possible to specifically detect noradrenaline in aqueous solutions and quantify it at relevant concentrations. In summary, by combining synthetic receptors with thermal measurement techniques it is possible to develop a portable sensor platform that is capable of low-cost and straightforward detection of biomolecules. Through exploring novel SPE substrates, a system is designed that is flexible and holds potential for the use in commercial biomedical devices and complex sensor architectures

Real-time analysis of microbial growth by means of the Heat-Transfer Method (HTM) using Saccharomyces cerevisiae as model organism

In this manuscript, we explore the use of the Heat-Transfer Method (HTM) for the real-time analysis of microbial growth using Saccharomyces cerevisiae as a model organism. The thermal responses of gold electrodes upon exposure to suspensions of S. cerevisiae (wild type strain DLY640) concentrations were monitored, demonstrating an increase in thermal resistance at the solid-liquid interface with higher concentrations of the microorganism. Flow cells were manufactured using 3D-printing to facilitate longitudinal experiments. We can clearly discriminate between the growth of S. cerevisiae under optimal conditions and under the influence of factors that inhibit the replication process, such as the use of nutrient depleted growth medium, elevated temperature, and the presence of toxic compounds. In addition, it is possible to determine the kinetics of the growth process and quantify yeast replication which was demonstrated by measuring a mutant temperature sensitive strain. This is the first time HTM has been used for the real-time determination of factors that impact microbial growth. Thermal sensing is low-cost, offers straightforward analysis and measurements can be performed on-site. Due to the versatility of this method, this platform can be extended to monitor other microorganisms and in particular to study the response of bacteria to selected antibiotics

Evaluatie van de nota Duurzame gewasbescherming

Dankzij wetgeving voor gewasbescherming is de waterkwaliteit vooruit gegaan, al zijn de beleidsdoelen voor de ecologische kwaliteit van het oppervlaktewater en voor de drinkwaterwinning niet bereikt. Ook bevat het oppervlaktewater op de helft van de meetlocaties nog te veel gewasbeschermingsmiddel. Wel zijn de beleidsdoelen voor voedselveiligheid en economie gehaald. De meeste zorg zit bij arbeidsveiligheid, vooral in de tuinbouw

Label-Free Detection of Escherichia coli Based on Thermal Transport through Surface Imprinted Polymers

This work focuses on the development of a label-free biomimetic sensor for the specific and selective detection of bacteria. The platform relies on the rebinding of bacteria to synthetic cell receptors, made by surface imprinting of polyurethane-coated aluminum chips. The heat-transfer resistance (Rth) of these so-called surface imprinted polymers (SIPs) was analyzed in time using the heat-transfer method (HTM). Rebinding of target bacteria to the synthetic receptor led to a measurable increase in thermal resistance at the solid–liquid interface. Escherichia coli and Staphylococcus aureus were used as model organisms for several proof-of-principle experiments, demonstrating the potential of the proposed platform for point-of-care bacterial testing. The results of these experiments indicate that the sensor is able to selectively detect bacterial rebinding to the SIP surface, distinguishing between dead and living E. coli cells on one hand and between Gram-positive and Gram-negative bacteria on the other hand (E. coli and S. aureus). In addition, the sensor was capable of quantifying the number of bacteria in a given sample, enabling detection at relatively low concentrations (104 CFU mL–1 range). As a first proof-of-application, the sensor was exposed to a mixed bacterial solution containing only a small amount (1%) of the target bacteria. The sample was able to detect this trace amount by using a simple gradual enrichment strategy