In 2020, the new European Drinking Water Directive will be updated to include new drinking-water safety parameters. These will introduce reduced thresholds for the presence of heavy metals, ...pesticides and other contaminants in domestic drinking water. The aim of these reduced thresholds is to impose a higher level of consumer protection as well as provide guidance for effective monitoring, planning and water management. An example of a newly proposed threshold is the concentration of lead ions (Pb
2+
) within drinking water, which has been reduced from 10 to 5 parts per billion (ppb). The strict timeframe for water suppliers to meet the new thresholds has created an impetus to develop
in situ
detection techniques to quantify the levels of chemical contamination on-site in drinking water, allowing them to make prompt interventions. This review explores and discusses the current advances related to electrochemical methods, electrode materials and modifications that have the potential to be the foundations of a new generation of portable electrochemical sensors towards trace-level ion
in situ
heavy metal sensors.
This Review explores the parameters to be engineered to design
in situ
electrochemical sensor platforms capable of meeting new EU regulation.
Screen-printed electrochemical sensing platforms, due to their scales of economy and high reproducibility, can provide a useful approach to translate laboratory-based electrochemistry into the field. ...An important factor when utilising screen-printed electrodes (SPEs) is the determination of their real electrochemical surface area, which allows for the benchmarking of these SPEs and is an important parameter in quality control. In this paper, we consider the use of cyclic voltammetry and chronocoulometry to allow for the determination of the real electrochemical area of screen-printed electrochemical sensing platforms, highlighting to experimentalists the various parameters that need to be diligently considered and controlled in order to obtain useful measurements of the real electroactive area.
This short article overviews the use of screen-printed electrodes (SPEs) in the field of electroanalysis and compares their application against traditional laboratory based analytical techniques. ...Electroanalysis coupled with SPEs can offer low-cost, precise, sensitive, rapid, quantitative information and laboratory equivalent results. The combined use of SPEs and electroanalysis reduces the need of sample transportation and preparation to a centralised laboratory allowing experimentalists to perform the measurements where they are needed the most. We first introduce the basic concepts and principles of analytical techniques to the reader, with particular attention to electroanalysis, and then discuss the application of SPEs to common analytical targets such as food, environmental, forensics, cancer biomarkers and pathogenic monitoring and sensing.
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2D hexagonal boron nitride (2D-hBN) is a lesser utilised material than other 2D counterparts in electrochemistry due to initial reports of it being
non-conductive
. As we will demonstrate in this ...review, this common misconception is being challenged, and researchers are starting to utilise 2D-hBN in the field of electrochemistry, particularly as the basis of electroanalytical sensing platforms. In this critical review, we overview the use of 2D-hBN as an electroanalytical sensing platform summarising recent developments and trends and highlight future developments of this interesting, often overlooked, 2D material.
This paper reports the detection of the inflammatory and sepsis-related biomarker, interleukin-6 (IL-6), in human blood plasma using functionalized screen-printed electrodes (SPEs) in conjunction ...with a thermal detection methodology, termed heat-transfer method (HTM). SPEs are functionalized with antibodies specific for IL-6 through electrodeposition of a diazonium linking group and N′-ethylcarbodiimide hydrochloride (EDC) coupling, which was tracked through the use of cyclic voltammetry and Raman spectroscopy. The functionalized SPEs are mounted inside an additively manufactured flow cell and connected to the HTM device. We demonstrate the ability to detect IL-6 at clinically relevant concentrations in PBS buffer (pH = 7.4) with no significant interference from the similarly sized sepsis-related biomarker procalcitonin (PCT). The limit of detection (3σ) of the system is calculated to correspond to 3.4 ± 0.2 pg mL–1 with a working range spanning the physiologically relevant concentration levels in both healthy individuals and patients with sepsis, indicating the sensitivity of the sensor is suitable for the application. Further experiments helped provide a proof-of-application through the detection of IL-6 in blood plasma with no significant interference observed from PCT or the constituents of the medium. Due to the selectivity, sensitivity, straightforward operation, and low cost of production, this sensor platform has the potential for use as a traffic light sensor for the multidetection of inflammatory biomarkers for the diagnosis of sepsis and other conditions in which the rapid testing of blood biomarkers has vital clinical application.
We compute for the first time the τ data-driven Euclidean windows for the hadronic vacuum polarization contribution to the muon g−2. We show that τ-based results agree with the available lattice ...window evaluations and with the full result. On the intermediate window, where all lattice evaluations are rather precise and agree, τ-based results are compatible with them. This is particularly interesting, given that the disagreement of the e+e− data-driven result with the lattice values in this window is the main cause for their discrepancy, affecting the interpretation of the aμ measurement in terms of possible new physics.
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•Intelligent forecasting of black-frost of greenhouses by using ANN and FES models.•Ecological anti-disaster system frost irrigation in greenhouses through Fuzzy Associative Memory ...(FAM).•Use of internet of things (IoT) in greenhouses via learning of neuro-fuzzy systems.•Smart irrigation management and anti-disaster frost irrigation by ANOVA data validation.
This paper is aimed at continuation of frost intelligent control from the smart farming perspective that is proposed by Castañeda and Castaño (2017) through Internet of things (IoT) and a Weather Station with an Artificial Neural Network (ANN). Moreover, an intelligent anti-frost irrigation management system is presented. The climatological station and the ecological anti-disaster frost irrigation interact with the environmental system through a website, allowing the real time interconnection, acquisition and monitoring of information through mobile phone systems (GSM/GPRS) and internet (TCP/IP) services. The system is self-sustaining through the use of solar panels. The ANN could be used to optimally predict the inside temperature of greenhouses and a Fuzzy Expert System (FES) controls the activation of a water pump. The ANN input variables involve the relative humidity, temperature of outside air, solar radiation, wind speed and inside air relative humidity. The fuzzy control and ANN allows the prediction of the internal temperature of the greenhouse and the cropland temperature, which are used to activate the anti-frost water distribution system. The ANN models give a temperature prediction through the coefficient of determination of variance analysis (ANOVA) method. The R2 values for temperature in summer season were 90.23, and 91.30; and for the winter season were 94.28, and 95.22, respectively. The fuzzy associative memory (FAM) controls the activation of the anti-frost irrigation system with five outputs for controlling the climatological frost presence: No-frost (NF), Possible-frost (PF), Mild-frost (MF), Severe-frost (SF) and Hard-frost (HF).
Additively manufactured (AM) supercapacitor platforms are fabricated from bespoke filaments, which are comprised of electro‐conductive graphene (20 wt%) incorporated polylactic acid (80 wt%), via ...fused deposition modeling and denoted as G/AMEs. The G/AMEs are shown to be capable of acting as a template for the electrodeposition of metals/metal oxides, in particular MoO2 nanowires (MoO2‐G/AMEs), which are subsequently explored as a capacitor within 1 m H2SO4, 1‐butyl‐3‐methylimidazolium hexafluorophosphate, and 1‐butyl‐3‐methylimidazolium tetrafluoroborate. Optimization of the MoO2‐G/AMEs demonstrates capacitance up to 1212 F g–1 when used in a symmetric arrangement. The material science described herein represents a significant enhancement in unlocking AMs potential as a valid manufacturing route for device level capacitance architectures.
Additively manufactured supercapacitor platforms are fabricated from bespoke filaments, which are comprised of electro‐conductive graphene (20 wt%) incorporated polylactic acid (80 wt%), via fused deposition modeling. These platforms are shown to act as an electrodeposition template where MoO2 nanowires are fabricated and give rise to outstanding supercapacitance performance within ionic liquids.
We present the fabrication of platinum (Pt
0
) nanoparticle (
ca
. 3 nm average diameter) decorated vertically aligned graphene (VG) screen-printed electrodes (Pt/VG-SPE) and explore their ...physicochemical characteristics and electrocatalytic activity towards the hydrogen evolution reaction (HER) in acidic media (0.5 M H
2
SO
4
). The Pt/VG-SPEs exhibit remarkable HER activity with an overpotential (recorded at −10 mA cm
−2
) and Tafel value of 47 mV (
vs
. RHE) and 27 mV dec
−1
. These values demonstrate the Pt/VG-SPEs as significantly more electrocatalytic than a bare/unmodified VG-SPE (789 mV (
vs
. RHE) and 97 mV dec
−1
). The uniform coverage of Pt
0
nanoparticles (
ca
. 3 nm) upon the VG-SPE support results in a low loading of Pt
0
nanoparticles (
ca
. 4 μg cm
−2
), yet yields comparable HER activity to optimal Pt based catalysts reported in the literature, with the advantages of being comparatively cheap, highly reproducible and tailorable platforms for HER catalysis. In order to test any potential dissolution of Pt
0
from the Pt/VG-SPE surface, which is a key consideration for any HER catalyst, we additively manufactured (AM) a bespoke electrochemical flow cell that allowed for the electrolyte to be collected at regular intervals and analysed
via
inductively coupled plasma optical emission spectroscopy (ICP-OES). The AM electrochemical cell can be rapidly tailored to a plethora of geometries making it compatible with any size/shape of electrochemical platform. This work presents a novel and highly competitive HER platform and a novel AM technique for exploring the extent of Pt
0
nanoparticle dissolution upon the electrode surface, making it an essential study for those seeking to test the stability/catalyst discharge of their given electrochemical platforms.
Platinum nanoparticle vertically aligned graphene (VG) screen-printed electrodes (Pt/VG-SPE) are fabricated with their physicochemical characteristics and electrocatalytic activity explored towards the hydrogen evolution reaction.
•Development of ARX and ANN models to predict the internal temperature of greenhouses.•Temperature predictor using a MLP-ANN trained by Levenberg-Marquardt-BP algorithm.•Data validation by the ANOVA ...method and compared with the ARX model.•The frost predictor of MLP-ANN could be used for an intelligent control in greenhouses.
Thermal comfort in greenhouses is a key fact to enhance productivity, due to the excess demand of energy for heating, ventilation and agroclimatic conditioning. Frost, in particular, represents a serious technological challenge if the crop sustainability is to be ensured. A Multi-Layer Perceptron artificial neural network, trained by a Levenberg-Marquardt backpropagation algorithm was designed and implemented for the smart frost control in greenhouses in the central region of Mexico, with the outside air temperature, outside air relative humidity, wind speed, global solar radiation flux, and inside air relative humidity as the input variables. The results showed a 95% confidence temperature prediction, with a coefficient of determination of 0.9549 and 0.9590, for summer and winter, respectively.
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