Commercial Probe Research Articles

Inline Determination of the Gel Elastic Modulus During Milk Coagulation Using a Multifiber Optical Probe

AbstractFrom a state-of-the-art point of view, it is currently possible to optically monitor the enzymatic coagulation of milk for real time estimation of the elastic modulus to cut the gel at optimum gel firmness. However, European cheese industry produces a wide variety of cheeses, many of them artisanal, and has a very fragmented productive structure with many small-, medium-sized companies. Therefore, if the technology is to be successfully uptake, it must be not only accurate but very low-cost. The objective of this work was to evaluate a low-cost commercial multifiber probe, for inline optical determination of curd firmness during cheese making. Preliminary tests were carried out to select the most appropriate fiber core size and wavelength and after that coagulation trials were performed following a fully randomized factorial design with two factors, i.e., concentration of protein (3.2, 3.6 and 4.0%) and added calcium (150, 200 and 250 mg L−1), with three replicates. The observed linear increase of the least square means of the initial voltage with the protein content (V0 = 0.15[P, %] + 0.88; R2 = 0.999), will be likely synergistic with the elastic modulus prediction if the model needs to be corrected for protein. Finally, the multifiber probe allowed predicting curd firmness using the proposed model with SEP values < 7 Pa. The present work has proven that a low-cost multifiber probe is suitable for accurate, real-time prediction of curd firmness during cheese manufacture.

Ready for new waves: optimizing SARS-CoV-2 variants monitoring in pooled samples with droplet digital PCR.

The declaration of the end of the Public Health Emergency for COVID-19 on May 11th, 2023, has shifted the global focus led by WHO and CDC towards monitoring the evolution of SARS-CoV-2. Augmenting these international endeavors with local initiatives becomes crucial to not only track the emergence of new variants but also to understand their spread. We present a cost-effective digital PCR-based pooled sample testing methodology tailored for early variant surveillance. Using 1200 retrospective SARS-CoV-2 positive samples, either negative or positive for Delta or Omicron, we assessed the sensitivity and specificity of our detection strategy employing commercial TaqMan variant probes in a 1:9 ratio of variant-positive to variant-negative samples. The study achieved 100% sensitivity and 99% specificity in 10-sample pools, with an Area Under the Curve (AUC) exceeding 0.998 in ROC curves, using distinct commercial TaqMan variant probes. The employment of two separate TaqMan probes for both Delta and Omicron establishes dual validation routes, emphasizing the method's robustness. Although we used known samples to model realistic emergence scenarios of the Delta and Omicron variants, our main objective is to demonstrate the versatility of this strategy to identify future variant appearances. The utilization of two divergent variants and distinct probes for each confirms the method's independence from specific variants and probes. This flexibility ensures it can be tailored to recognize any subsequent variant emergence, given the availability of its sequence and a specific probe. Consequently, our approach stands as a robust tool for tracking and managing any new variant outbreak, reinforcing our global readiness against possible future SARS-CoV-2 waves.

Non-Contact Current Measurement for Three-Phase Rectangular Busbars Using TMR Sensors.

This paper proposes a non-contact current measurement method for three-phase rectangular busbars based on TMR (tunneling magneto-resistance) sensors, due to their advantages of large dynamic range, wide bandwidth, light weight, and easy installation. A non-contact current sensor composed of only three TMR sensors is developed and the TMR sensors are respectively placed at a location with a certain distance from the surface of each rectangular busbar to measure the magnetic fields generated by the busbar currents. To calibrate the developed current sensor, i.e., to establish the relationship between the magnetic fields measured by the TMR sensors and the currents flowing in the three-phase rectangular busbars, we designed a thyristor-controlled resistive load as a calibrator, which is connected to a downstream branch of the distribution cabinet. By switching the resistive load, a calibration current, which can be identified from the background current, is generated in one rectangular busbar and its value is measured at the location of the calibrator, and transmitted wirelessly to the location of the TMR sensors. A new and robust method is proposed to extract the voltage components, corresponding to the calibration current, from the voltage waveforms of the TMR sensors. By calculating the proportional coefficients between the calibration currents and the extracted voltage components, online calibration of the current sensor is achieved. We designed and implemented a current measurement system consisting of a current sensor using TMR sensors, a thyristor-controlled resistive load for current sensor calibration, and a data acquisition circuit based on a multi-channel analog-to-digital converter (ADC). Current measurement experiments were performed in a practical distribution cabinet installed in our laboratory. Compared to the measurement results using a commercial current probe with an accuracy of 1%, the relative error of the measured currents in RMS is less than 2.5% and the phase error is less than 1°, while the nonlinearity error of the current sensor is better than 0.8%.

A de novo zwitterionic strategy of ultra-stable chemiluminescent probes: highly selective sensing of singlet oxygen in FDA-approved phototherapy.

Singlet oxygen (1O2), as a fundamental hallmark in photodynamic therapy (PDT), enables ground-breaking clinical treatment in ablating tumors and killing germs. However, accurate in vivo monitoring of 1O2 remains a significant challenge in probe design, with primary difficulties arising from inherent photo-induced side reactions with poor selectivity. Herein, we report a generalizable zwitterionic strategy for ultra-stable near-infrared (NIR) chemiluminescent probes that ensure a highly specific [2 + 2] cycloaddition between fragile electron-rich enolether units and 1O2 in both cellular and dynamic in vivo domains. Innovatively, zwitterionic chemiluminescence (CL) probes undergo a conversion into an inert ketone excited state with an extremely short lifetime through conical intersection (CI), thereby affording sufficient photostability and suppressing undesired photoreactions. Remarkably, compared with the well-known commercial 1O2 probe SOSG, the zwitterionic probe QMI exhibited an ultra-high signal-to-noise ratio (SNR, over 40-fold). Of particular significance is that the zwitterionic CL probes demonstrate excellent selectivity, high sensitivity, and outstanding photostability, thereby making a breakthrough in real-time tracking of the FDA-approved 5-ALA-mediated in vivo PDT process in living mice. This innovative zwitterionic strategy paves a new pathway for high-performance NIR chemiluminescent probes and high-fidelity feedback on 1O2 for future biological and medical applications.

High-Frequency Linear Array (20 MHz) Based on Lead-Free BCTZ Crystal.

Centimeter-sized BaTiO3-based crystals grown by top-seeded solution growth from the BaTiO3-CaTiO3-BaZrO3 system were used to process a high-frequency (HF) lead-free linear array. Piezoelectric plates with (110)pc cut within 1° accuracy were used to manufacture two 1-3 piezo-composites with thicknesses of 270 and [Formula: see text] for resonant frequencies in air of 10 and 30 MHz, respectively. The electromechanical characterization of the BCTZ crystal plates and the 10-MHz piezocomposite yielded the thickness coupling factors of 40% and 50%, respectively. We quantified the electromechanical performance of the second piezocomposite (30 MHz) according to the reduction in the pillar sizes during the fabrication process. The dimensions of the piezocomposite at 30 MHz were sufficient for a 128-element array with a 70- [Formula: see text] element pitch and a 1.5-mm elevation aperture. The transducer stack (backing, matching layers, lens, and electrical components) was tuned with the characteristics of the lead-free materials to deliver optimal bandwidth and sensitivity. The probe was connected to a real-time HF 128-channel echographic system for acoustic characterization (electroacoustic response and radiation pattern) and to acquire high-resolution in vivo images of human skin. The center frequency of the experimental probe was 20 MHz, and the fractional bandwidth at -6 dB was 41%. Skin images were compared against those obtained with a lead-based 20-MHz commercial imaging probe. Despite significant differences in sensitivity between elements, in vivo images obtained with a BCTZ-based probe convincingly demonstrated the potential of integrating this piezoelectric material in an imaging probe.

Молекулярно-цитогенетическая характеристика малых сверхчисленных маркерных хромосом 15 и 22 у асимптоматических носителей

Small supernumerary marker chromosomes (sSMC) are structurally abnormal chromosomes that cannot be identified unambiguously by standard cytogenetic methods. A comprehensive approach involving the use of molecular cytogenetic methods is required for the more thorough morphological assessment of such chromosomes, as well as for the development of strategy for genetic counseling of the patients being the sSMC carriers. It is widely accepted that the development of abnormal phenotype by the patients having sSMC in their karyotype is associated with the presence of euchromatic region material in the marker chromosome. Therefore, it results from the presence of relatively large DNA copy number variations (CNVs) in the form of duplication, triplication, and more increased copy numbers; which are localized in the pericentromeric region of the appropriate chromosome. Pericentromeric CNVs can be involved in the chromosome imbalance in asymptomatic carriers of sSMC as well, however, the boundaries of such imbalance have not been clearly identified. The study was aimed to acquire additional information about the genomic topology of the DNA regions insensitive to the genes copy number increase. FISH analysis with commercial and homemade DNA probes was performed in 18 carriers of sSMC 15 and 22 having no clinically significant phenotypic abnormalities. The molecular cytogenetic testing showed that pericentromeric euchromatic regions sized 1.2 Mb and 714 kb, respectively, were found in 33% of cases (6 out of 18). We assume that these regions comprise no potentially dosage-sensitive genes.

Plasmonic Nanocone Scanning Antenna: Fabrication and Optical Properties

Optical antennas are nanostructures that introduce unprecedented possibilities for light–matter interaction at the nanoscale. An appropriately tailored plasmonic antenna can enhance the total radiative decay rate and modify the angular radiation pattern of a single‐quantum emitter through controlled near‐field coupling. Despite their ability to surpass the fundamental diffraction limit and confine the electromagnetic field to a tiny mode volume, fabricating 3D sharp scanning nanoscale plasmonic structures with desired aspect ratio is yet an ambitious goal. The fabrication of nanocones by gold evaporation on commercial atomic force microscopy probes followed by a focused ion beam milling technique is presented. The method is versatile and allows the fabrication of nanocones with desired dimensions around 100 nm along with an aspect ratio of ≈1. Their optical properties are studied and it is shown how the variation in the refractive index of the dielectric substrate affects the localized surface plasmon resonance of the nanocones, the decay rate enhancement, and the quantum yield of an emitter relevant for fluorescence/Raman scanning experiments. Theoretical studies using finite‐difference time‐domain calculations have guided the fabrication process and are consistent with experimental results.

Simple and cost-effective pH and T sensors from top to bottom: New chemical probes based on sonogel-carbon transducers for plasma analyses

The present work introduces two novel approaches to fabricate simple and cost-effective pH and temperature probes. Sinusoidal voltage methodologies were employed to electrodeposit polyaniline (PANI) at different growth times (10–20 min) on the surface of an affordable Sonogel-Carbon electrode to conform a robust pH sensor. The presence of PANI and its phases were corroborated by electrochemical means. The sensibility, reversibility and selectivity of the produced sensor were very adequate to apply it in physiological samples. In this regard, the proposed sensor was evaluated in artificial blood serum as well as untreated plasma samples obtaining outstanding results in comparison with a gold reference technique (error <2 %). In addition, a new composite sonogel material, intrinsically modified with multiwalled carbon nanotubes, was attached on top of an electrode couple to one-step fabricate a new temperature probe, relating resistance of the probe with the surroundings temperature. In this case, an optical microscopy characterization was performed to study the sturdiness of the layer. Remarkably, suitable results in terms of sensitivity and selectivity were obtained. The probes were assessed in artificial and untreated plasma samples as well, with the corresponding validation step (error <1 %) by using a commercial temperature probe.

Visualizing pH and Mass Transport at Hydrogen Evolving Electrodes with Fluorescence Lifetime Microscopy

The chemical industry needs electrochemical solutions to avoid large CO₂ emissions. However, many of these electrochemical processes suffer from poor mass transport around the catalyst. To optimize these technologies, we need to gain a better understanding of the local processes at the electrode. This could give us ideas of new catalyst and reactor designs to enhance mass transport.The pH is a parameter that helps us to understand these processes. This is because the catalyst stability and selectivity of many reactions is strongly dependent on the local pH. You need a non-invasive technique to measure in operando spatial maps of pH. Optical techniques are a logical route for this.Fluorescence Lifetime Imaging Microscopy (FLIM) is a technique that measures the fluorescence lifetime of a probe molecule. It is friendly to use, as it is self-referencing (i.e. you do not need to calibrate your system for every new measurement). Many electrochemical applications, like seawater electrolysis, CO2 reduction and alkaline water electrolysis, tend to work in alkaline conditions (pH >8). Unfortunately commercial FLIM probes are only available in neutral and mildly acidic pH (4 to 8), owing to their use in biological systems.We have developed new fluorescence lifetime probes based on the 1-methyl-7-amino-quinolinium fluorophore molecules, that allow pH measurements in the range of pH 5.5-13. We have used the probes to visualise the local pH around a hydrogen evolving electrode and can show the boundary layer that forms close to the electrode and investigate how it is disturbed by gas bubbles at a rate of 3 fps and resolution of 4 μm. Figure 1

DNA‐Barcoded Plasmonic Nanostructures for Activity‐Based Protease Sensing

AbstractWe report the development of a new class of protease activity sensors called DNA‐barcoded plasmonic nanostructures. These probes are comprised of gold nanoparticles functionalized with peptide‐DNA conjugates (GPDs), where the peptide is a substrate of the protease of interest. The DNA acts as a barcode identifying the peptide and facilitates signal amplification. Protease‐mediated peptide cleavage frees the DNA from the nanoparticle surface, which is subsequently measured via a CRISPR/Cas12a‐based assay as a proxy for protease activity. As proof‐of‐concept, we show activity‐based, multiplexed detection of the SARS‐CoV‐2‐associated protease, 3CL, and the apoptosis marker, caspase 3, with high sensitivity and selectivity. GPDs yield &gt;25‐fold turn‐on signals, 100‐fold improved response compared to commercial probes, and detection limits as low as 58 pM at room temperature. Moreover, nanomolar concentrations of proteases can be detected visually by leveraging the aggregation‐dependent color change of the gold nanoparticles. We showcase the clinical potential of GPDs by detecting a colorectal cancer‐associated protease, cathepsin B, in three different patient‐derived cell lines. Taken together, GPDs detect physiologically relevant concentrations of active proteases in challenging biological samples, require minimal sample processing, and offer unmatched multiplexing capabilities (mediated by DNA), making them powerful chemical tools for biosensing and disease diagnostics.

DNA-Barcoded Plasmonic Nanostructures for Activity-Based Protease Sensing.

We report the development of a new class of protease activity sensors called DNA-barcoded plasmonic nanostructures. These probes are comprised of gold nanoparticles functionalized with peptide-DNA conjugates (GPDs), where the peptide is a substrate of the protease of interest. The DNA acts as a barcode identifying the peptide and facilitates signal amplification. Protease-mediated peptide cleavage frees the DNA from the nanoparticle surface, which is subsequently measured via a CRISPR/Cas12a-based assay as a proxy for protease activity. As proof-of-concept, we show activity-based, multiplexed detection of the SARS-CoV-2-associated protease, 3CL, and the apoptosis marker, caspase 3, with high sensitivity and selectivity. GPDs yield >25-fold turn-on signals, 100-fold improved response compared to commercial probes, and detection limits as low as 58 pM at room temperature. Moreover, nanomolar concentrations of proteases can be detected visually by leveraging the aggregation-dependent color change of the gold nanoparticles. We showcase the clinical potential of GPDs by detecting a colorectal cancer-associated protease, cathepsin B, in three different patient-derived cell lines. Taken together, GPDs detect physiologically relevant concentrations of active proteases in challenging biological samples, require minimal sample processing, and offer unmatched multiplexing capabilities (mediated by DNA), making them powerful chemical tools for biosensing and disease diagnostics.

Rational design of a two-photon probe with solvatochromic emission and AIE-activity for lipid droplet specific imaging

Abnormal changes in numbers, sizes and polarities of lipid droplet (LD) are thought to be closely associated with varieties diseases such as fatty liver, diabetes, atherosclerosis and even cancer. However, there still exists some shortcomings of the current commercial LD probes, such as aggregation-caused quenching (ACQ) effect, small Stokes shifts, excitation wavelength restricted to visible light region, and lacking of two-photon excitation fluorescence, which restrict the diagnosis of LD related diseases. Herein, a two-photon aggregation-induced emission (AIE) bioprobe, namely TP-LDP, was rationally designed by constructing of the donor-acceptor-donor (D-A-D) structure for specific imaging of LD. TP-LDP exhibited AIE-activities, solvatochromic emissions (λemmax: 451–652 nm), extra-large Stokes shifts (11550 cm−1) as well as two-photon absorption ability (156 GM). More importantly, cellular experiments demonstrated that TP-LDP possessed excellent photostability, nice two-photon excited fluorescence imaging ability as well as precise LD-targeting, and successfully detected abnormal LD proliferations in living cells. These features enable TP-LDP to effectively compensate for the shortcomings of commercial LD dyes and have the potential to become a powerful tool for detecting LD related diseases.

Engineering of a NIR fluorescent probe for high-fidelity tracking of lipid droplets in living cells and nonalcoholic fatty liver tissues

LDs (Lipid droplets) are key organelles for lipid metabolism and storage, which are closely related to ferroptosis and fatty liver. Due to its small size and highly dynamic nature, developing high-fidelity fluorescent probes for imaging of LDs is crucial for observing the dynamic physiological processes of LDs and investigating LDs-associated diseases. Herein, we synthesized three dicyanoisophorone-based fluorescent probes (DCIMe, DCIJ, and DCIQ) with different electron-donating groups and studied their imaging performance for LDs. The results show that DCIQ is highly polarity sensitive and can perform high-fidelity imaging for LDs, with significantly better performance than DCIMe, DCIJ, and commercial LD probe BODIPY 493/503. Based on this, DCIQ was successfully applied to real-time observe the interplays between LDs and other organelles (mitochondria, lysosomes, and endoplasmic reticulum), and to image the dynamics of LDs with fast scanning mode (0.44 s/frame) and the generation of oleic acid-induced LDs with high-fidelity. Finally, DCIQ was used to study the changes of LDs in the ferroptosis process and nonalcoholic fatty liver disease tissues. Overall, this study provided a powerful tool for high-fidelity imaging of LDs in cells and tissues.

A Reconfigurable Tri-Mode Frequency-Locked Loop Readout Circuit for Biosensor Interfaces.

In this article, a frequency-locked loop (FLL) based multimodal readout integrated circuit (IC) for interfacing with off-chip temperature, electrochemical, and pH sensors is presented. By reconfiguring its switched-capacitor feedback network, the readout circuit is able to measure resistance, current, and voltage without additional active analog front-end circuits. A prototype IC was fabricated in a 0.18 μm CMOS process. Measured results show that when measuring resistance, the input-referred resistance resolution is 10.5 Ω for 100 Hz integration bandwidth. Using an off-chip thermistor, the readout circuit covers a temperature range of 0-75 °C and achieves an equivalent temperature resolution of 16.4 mKrms. In current mode, the readout circuit has an input range of 0.5μA and an input-referred current noise as low as 40.6 pArms for 100 Hz bandwidth. Interfacing with an on-chip potentiostat, glucose chronoamperometry is demonstrated. In voltage mode, a minimum input-referred voltage noise of 31.7 μVrms is achieved, and the IC can measure a pH range from 1.6 to 12 using a commercial pH probe. At a 1.2 V supply, power consumption of the readout circuit is below 10 μW for all three measurement modes. Additionally, the prototype IC includes an integrated wireless transmitter that implements on-off keying modulation, and a wireless multimodal sensing system utilizing the FLL-based readout circuit is demonstrated.

LoCoLotive: In silico mining for low-copy nuclear loci based on target capture probe sets and arbitrary reference genomes.

Universal target enrichment probe kits are used to circumvent the individual identification of loci suitable for phylogenetic studies in a given taxon. Under certain circumstances, however, target capture can be inefficient and costly, and lower numbers of marker loci may be sufficient. We therefore propose a computational pipeline that enables the easy identification of a subset of promising candidate loci for a taxon of interest. Target sequences used for probe design are filtered based on an assembled reference genome, resulting in presumably intron-containing single-copy loci as present in the reference taxon. The applicability of the proposed approach is demonstrated based on two probe kits (universal and family-specific) in combination with several publicly available reference genomes. Guided by commercial probe kits, LoCoLotive enables fast and cost-efficient marker mining. Its accuracy mainly depends on the quality of the reference genome and its relatedness to the taxa under study.

Memo1 reduces copper-mediated reactive oxygen species in breast cancer cells

The mediator of ERBB2-driven cell motility protein 1, Memo1, plays important roles in cancer signaling pathways. We recently reported Memo1 to coordinate reduced copper ions and protect them from reactive oxygen species (ROS) generation in vitro. We here assess if this Memo1 activity is at play in breast cancer cells. Copper additions to MDA-MB-231 cells promoted cell death, and this toxicity was exaggerated when Memo1 expression was reduced by silencing RNA. Using three different commercial ROS probes, we revealed that copper additions increased intracellular ROS levels, and these were further elevated when Memo1 expression was silenced. We propose that, in addition to other functions, Memo1 protects cancer cells from unwanted copper-mediated redox reactions. This may be a required safety mechanism in cancer cells as they have a high demand for copper.

Effect of Embedded Depth of Copper-Nickel-Plated Sensor Probes on Compressive Strength Development of Mortar

Embedded sensors are widely employed for the structural health monitoring of structures constructed with concrete or mortar. Despite embedded sensors being actively used, there has been no study on whether or not the sensor probe placement within structures made of concrete or mortar influences their structural stability. The strength of small structures in particular could be affected by sensor probes embedded within them. To address the lack of research in this area, this study analyzed the effect of embedding positions of sensor probes on the compressive strength development of mortar. After the production of mortar specimens with the depth of the embedded sensor being controlled by the developed mold, compressive strength tests were conducted, and then test results were verified through finite element analysis. For testing, copper–nickel-plated sensor probes were embedded within the mortar because these sensor probes are popular commercial probes. The test results show that the compressive strength was 7.1 MPa when the sensor probe was embedded at a depth of 5 mm. In contrast, the compressive strength was 28.2 MPa at a depth of 30 mm. Since the compressive strength without the embedded sensor probe was 29.8 MPa, considering the results of this study, it is highly recommended that copper–nickel-plated sensor probes be embedded at least 30 mm from the surface of mortar structures.

Arduinos in the wild: A novel, low‐cost sensor network for high‐resolution microclimate monitoring in remote ecosystems

The importance of microclimate conditions is becoming increasingly recognised in ecological research, especially as they can differ widely from macro‐ and mesoclimate. Effective measurement of microclimate variability in heterogeneous field conditions requires measurements from a large number of sensors, ideally sampling across both small and large scales, which necessitates the development of cost‐effective sensor networks. Here, we develop an environmental microcontroller (EMU) sensor network for measuring soil moisture and temperature with high spatiotemporal coverage. The system can easily be implemented in larger or smaller setups, though our study consisted of 40 plots distributed across 4 sites in northern Lapland. Using 40 EMUs, each equipped with 10 soil temperature and 10 soil moisture sensors, we collected roughly 3.5 million unique soil temperature and moisture records over the course of about 2 months. We then compared these measurements to those from commercial temperature sensors (iButtons) and TDR soil moisture probes. We show that our sensor network is able to successfully characterise microclimate variation at the site, plot and within‐plot scales with high accuracy and good reliability. Moreover, even including development costs, the total price per EMU unit was less than €100, yielding a much cheaper and higher resolution system than is currently available from commercial producers. For both temperature and soil moisture, we found a strong relationship between the sensor network measurement and those obtained from commercial systems. Roughly 10% of the overall spatial variation in temperature and moisture occurred within plots—that is. over the scale of 25–50 cm. Our results show that accurate measurements of microclimate soil temperature and soil moisture can be obtained using low‐cost sensor networks. We also show that microclimate variability at small scales can make up a considerable fraction of total environmental variability. To this end, we discuss some of the difficulties encountered during the development process and suggest possible improvements for further studies. While the sensor network described here can be applied without any modifications for quantifying topsoil conditions, we note that with minor changes to our code and hardware, the system can be customised for other kinds of measurements.

Topographic Drivers of Soil Moisture Across a Large Sensor Network in the Southern Appalachian Mountains (USA)

AbstractUnderstanding the distribution of soil moisture is notoriously difficult in topographically complex regions that are subject to both large‐scale climate gradients and fine‐scale effects of terrain, vegetation, and soil structure. Remote sensing approaches capture large‐scale moisture patterns but are limited in spatial and temporal resolution, while commercial field sensors remain too expensive to deploy intensively over large spatial extents. Here, we demonstrate the use of low‐cost (&lt;20 USD) custom sensors to create a large monitoring network of surficial (0–15 cm depth) volumetric soil moisture content (VMC) across Great Smoky Mountains National Park (GSMNP) (NC, TN, USA). In laboratory tests, temperature‐calibrated VMC values approached the accuracy of commercial probes. We deployed over 80 sensors across multiple watersheds, topographic positions, and a 1,800‐m elevation gradient, and created hierarchical models to understand associations of VMC with spatial (30‐m resolution) and temporal (daily) variables related to water supply and demand. Elevation had the strongest association with VMC, with a fivefold increase across the gradient reflecting 1.5‐fold changes in both (increased) precipitation and (decreased) evapotranspiration; slope angle was a strong mediating factor. Common proxies for moisture including topographic convergence index were not associated with VMC, likely due to limited contributions of surface drainage to local water balance. Our model predicted daily VMC of a set of validation sensors with a root mean square error of 4.8%, which may be improved by site‐specific field calibration. Our study indicates that spatially extensive, field‐based soil moisture networks are practical, accurate, and an important component of regional environmental monitoring.

A novel mathematical template for developing fDOM probe fluorescence signal correction models for freshwaters

The reliable application of field deployable fluorescent dissolved organic matter (fDOM) probes is hindered by several influencing factors which need to be compensated. This manuscript describes the corrections of temperature, pH, turbidity and inner filter effect on fluorescence signal of a commercial fDOM probe (fDOMs). For this, Australian waters with wide ranging qualities were selected, e.g. dissolved organic carbon (DOC) ranging from ∼1 to ∼30 mg/L, specific UV absorbance at 254 nm from ∼1 to ∼6 L/m/mg and turbidity from ∼1 to ∼ 350 FNU. Laboratory-based model calibration experiments (MCEs) were performed. A model template was developed and used for the development of the correction models. For each factor, data generated through MCEs were used to determine model coefficient (α) values by fitting the generated model to the experimental data. Four discrete factor models were generated by determination of a factor-specific α value. The α values derived for each water of the MCEs subset were consistent for each factor model. This indicated generic nature of the four α values across wide-ranging water qualities. High correlation between fDOMs and DOC were achieved after applying the four-factor compensation models to new data (r, 0.96, p < 0.05). Also, average biases (and %) between DOC predicted through fDOMs and actual DOC were decreased by applying the four-factor compensation model (from 3.54 (60.9%) to 1.28 (16.7%) mg/L DOC). These correction models were incorporated into a Microsoft EXCEL-based software termed EXOf-Correct for ready-to-use applications.