bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Keynote) Blood, Sweat and Tears... – Sensing of Human Performance Biomarkers in Bodily Fluids Using Point-of-Use Devices
Authors: Steckl Andrew 
Published: July 2021

Hormones produced by glands in the endocrine system and neurotransmitters produced by the nervous system control many bodily functions. The concentrations of these molecules in the body are an indication of its state, hence the use of the term biomarker. Excess concentrations of biomarkers, such as cortisol, serotonin, epinephrine, dopamine, are released by the body in response to a variety of conditions - emotional state (euphoria, stress), disease, etc. The development of simple, low-cost modalities for point-of-use (PoU) measurements of biomarkers levels in various bodily fluids (blood, urine, sweat, saliva) as opposed to conventional hospital or lab settings is receiving increasing attention. The presentation starts with a review of the basic properties of primary stress-related biomarkers: origin in the body (i.e. if they are produced as hormones, neurotransmitters or both), chemical composition, molecular weight (small/medium size molecules and polymers, ranging from ~100Da to ~100kDa), hydro- or lipo-philic nature. Next, a review of the published literature is presented regarding the concentration of these biomarkers found in several bodily fluids that can serve as the medium for determination of the condition of the subject: blood, urine, saliva, sweat and, to a lesser degree, interstitial tissue fluid. The concentration of various biomarkers in most fluids covers a range of 5-6 orders of magnitude, from 100s of ng/mL (~1µM) down to a few pg/mL (sub 1pM). Mechanisms and materials for point-of-use biomarker sensors are summarized and key properties are reviewed. Illustrative examples from the literature are discussed for several sensor device categories, including lateral flow (immuno)assay devices and microfluidic devices. Selected methods for detecting these biomarkers are reviewed, including antibody- and aptamer-based colorimetric assays, electrochemical and optical detection. Finally, the presentation outlines key challenges of the field and provides a look ahead to future prospects.
A. J. Steckl and P. Ray, “A Review of Stress Biomarkers Concentrations in Bodily Fluids and Their Point-of-Use Detection”, ACS Sensors, 3 (10), 2025-2044, Sept 2018 (10.1021/acssensors.8b00726)
V. Venkatraman and A. J. Steckl, “Quantitative Detection in Lateral Flow Immunoassay Using Integrated Organic Optoelectronics”, IEEE Sensors, 17 (24), 8343, Dec 2017 (10.1109/JSEN.2017.2764178 ).
P. Ray and A. J. Steckl, “Label-Free Optical Detection of Multiple Stress Biomarkers in Sweat, Plasma, Urine and Saliva”, ACS Sensors
4, 2019. (10.1021/acssensors.9b00301)
S. Dalirirad and A. J. Steckl, “Aptamer-Based Lateral Flow Assay for Point of Care Cortisol Detection in Sweat”, Sensors & Actuators
283, 79-86, Jan 2019 (https://doi.org/10.1016/j.snb.2018.11.161).

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In Brain and in Vein Detection of Antibiotics Using Electrochemical-DNA Biosensors
Authors: Dauphin Ducharme Philippe 
Published: July 2021

Current approaches towards drug dosing rely on venous draws measurements performed on test patients which are laboratory-analyzed and returned the following days. This practice forces physicians to administer potentially toxic or ineffective concentrations of drugs to patients since dosages are determined based on weight and age of this test group even though pharmacokinetics may differ in each individuals. Having a technology that would in contrast allow, direct, continuous, real-time monitoring of drugs in the living body would revolutionize healthcare and allow personalized drug dosage and adjustment while enabling the development of artificial organs responsible of adjusting these levels.
Motivated by this goal, we have developed a class of electrochemical aptamer-based (E-AB) sensors[1]. These sensors are comprised of a redox-reporter-modified DNA “probe” that is attached by one terminus to a self-assembled monolayer deposited on an interrogating electrode. The binding of an analyte to this probe alters the kinetics with which electrons exchange to/from the redox reporter via binding-induced conformational changes producing an easily measured change in current when the sensor is interrogated using square-wave voltammetry (see Figure) [2]. E-AB sensors are capable of detecting with high specificity their molecular targets in flowing whole blood and directly in the living body. I will present during this presentation some of these sensors deployed in the vein [3] and in the brain of sedated rats to monitor the pharmacokinetics of the antibiotic, vancomycin. The ability of acquiring high frequency measurements of drug plasma levels using these biosensors has also allowed us to develop a technology that improves our ability to deliver them [3]. Due to their small size, these sensors can also be deployed directly in the brain of freely moving animals to monitor molecules with unmatched temporal resolution [4]. All these advancement in developing E-AB sensors are aimed towards developing new analytical tools for personalized medicine while improving our understanding of drug metabolism.
[1]: Dauphin Ducharme, P. and Plaxco, K. W. Anal. Chem. 2016, 88, 11654–11662.
[2]: Li, H., Dauphin Ducharme, P., Ortega, G., Plaxco, K. W. J Am. Chem. Soc. 2017, 139, 11207-11213.
[3]: Dauphin-Ducharme, P., Yang, K., Arroyo-Currás, N., Ploense, K., Zhang, Y., Gerson, J., Kurnik, M., Kippin, T. E., Stojanovic, M., Plaxco, K. W. ACS Sensors 2019, 4, 2832-2837.
[4]: Ploense, K., Dauphin-Ducharme, P., Arroyo-Currás, N., Williams, S.; Schwarz, N., Kippin, T. E., Plaxco, K. W. 2020 Under review.

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(Invited) Exploring in the Near Infrared: Multifunctional Nanoplatforms for Biomedical Applications
Authors: Ma Dongling 
Published: July 2021

Near-infrared (NIR) absorbing and emitting nanomaterials attract significant attention in bioimaging, which shows great potential for disease detection due to its high sensitivity at the subcellular level and low cost of related imaging facilities. However, currently available optical probes are mainly based on visible-emitting materials. The tissue-induced optical extinction and autofluorescence in the visible range result in limited penetration depth and ambiguous photoluminescence signal, which restricts their in vivo use. To address this issue, photoluminescent probes, with both absorption and emission wavelengths operating in the biological windows in the NIR range, in which tissues are optically transparent, are highly desired. Their integration with superparamagnetic nanomaterials to make a multifunctional platform further opens a wide range of promising applications, including bimodal imaging (photoluminescence and magnetic resonance imaging), synergistic hyperthermia (magnetothermal and photothermal), magnetic confinement of trace amounts of biospecies for ultra high-sensitivity biodetection, etc. In this talk, I will present our most recent work on the synthesis of NIR-emitting water soluble, stable core/shell/shell quantum dots (QDs) and multifunctional (NIR photoluminescent and superparamagnetic) nanoparticles and their use in biomedicine. For instance, in one case, multifunctional particles contain single superparamagnetic nanoparticles as cores and NIR-luminescent nanomaterials as shells. In another case, the multifunctional nanoplatform is compose of multiple superparamagnetic nanoparticles and NIR quantum dots in single particles. These different types of multifunctional particles are designed for different biomedical applications.
References: [1] ACS Nano 2019, 13, 408-420; [2] Adv. Funct. Mater. 2018, 1706235 (Inside Back Cover); [3] Chem. Mater. 2019, 31, 3201-3210.
Capacitive Electrochemical Sensor with Molecularly Imprinted Polymer for Determination of Heterocyclic Aromatic Amines
Authors: Ayerdurai Viknasvarri , Garcia-Cruz Alvaro , Cieplak Maciej , Sharma Piyush Sindhu , D'Souza Francis , Kutner Wlodzimierz 
Published: July 2021

Quinoxaline heterocyclic aromatic amines (HAAs), are formed during meat and fish cooking, frying, or grilling at high temperatures. HAAs are classified as potent hazardous carcinogens, even though the HAAs are usually generated at very low concentrations (~ng per g of a food sample). This is because the HAA food contaminants effectively damage DNA by intercalation or strand break. Hence, chronic exposure to HAAs, even in low doses, can cause cancers of the lung, stomach, breast, etc. Currently, HPLC is used for the determination of these toxins in food matrices. However, this technique is expensive, tedious, and time-consuming. Therefore, fast, simple, inexpensive, and reliable HAAs determination procedures, without the need for separation of these toxins, in the protein food matrices are in demand. Molecularly imprinted polymers (MIPs) are excellent examples of bio-mimicking recognition materials. Therefore, they have found numerous applications in selective chemosensing. Within the present project, we synthesized a nucleobase-functionalized molecularly imprinted polymer (MIP) as the recognition unit of an electrochemical sensor for selective DPV and capacitive detection and determination of 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (7,8-DiMeIQx) HAA. MIP-(7,8-DiMeIQx) film-coated electrodes were sensitive and selective to 7,8-DiMeIQx. The linear dynamic concentration range of the devised chemosensor extended from 12 µM to 0.4 mM 7,8-DiMeIQx and the imprinting factor was high, IF = 13.
The present work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 711859. Scientific work was funded from the financial resources for science in the years 2017-2021 awarded by the Polish Ministry of Science and Higher Education for the implementation of an international co-financed project and National Science Centre Poland (grant No. NCN 2014/15/B/NZ7/01011 to W.K.)
Fabrication of Electrochemical Biosensor for Detection of Full-Length Tau Protein through Biotin-Streptavidin on Gold Surface
Authors: Wallace William , Martic Sanela 
Published: July 2021

Tau is a neuronal protein responsible for microtubule formation [1]. It is also the pathological protein active in the Alzheimer’s Disease (AD) pathway. When Tau begins to aggregate as a result of misfolding, the neuronal cells die due to the lack of microtubule formation and can take on prion-like properties [2]. Therefore, detection of aggregated Tau can serve as a powerful tool in the early diagnosis of AD and dementia related diseases. As has been previously demonstrated, Tau 441 can be detected with an electrochemical immunoassay based on the electrochemical impedance spectroscopy (EIS) by using gold electrode [3]. The EIS was also used to monitor interactions between Tau protein and Heparin [4]. Herein, we describe use of EIS to monitor and detect Tau and its aggregates by using gold electrode modified to include a biotinylated aptamer to tau and streptavidin-Au sensor through a series of surface modifications. Surface modifications were characterized using EIS and CV. After modifying the surface of the electrode, the detection of Tau was achieved using EIS. Aggregation of tau was also monitored as a function of Tau or Heparin concentrations, and incubation time and temperature. The control experiments included, Tau-free surface, Heparin-free solution, buffer solution in order to minimize aggregation. The charge transfer resistance, Rct, was determined by fitting the experimental data to the equivalent circuit. The Rct values for Tau-films on gold surface were compared prior and post aggregation. The Rct values were highly dependent on the experimental conditions. Data indicate that this electrochemical sensor holds great promise for detection of neurodegenerative biomarkers which undergo aggregation.

References

[1] M.D. Weingarten, A.H. Lockwood, S. Hwo, M.W. Kirschner, A Protein Factor Essential for Microtubule Assembly, Natl. Acad Sci. 72 (1975) 1858–1862.
[2] F. Clavaguera, J. Hench, M. Goedert, M. Tolnay, Invited review: Prion-like transmission and spreading of tau pathology, Neuropathol. Appl. Neurobiol. 41 (2015) 47–58.
[3] N. Carlin, S. Martic-Milne, Anti-tau antibodies based electrochemical sensor for detection of tau protein biomarkers, J. Electrochem. Soc. 165 (2018) G3018–G3025.
[4] H. Trzeciakiewicz, J. Esteves-Villanueva, R. Soudy, K. Kaur, S. Martic-Milne, Electrochemical characterization of protein adsorption onto YNGRT-Au and VLGXE-Au surfaces, Sensors (Switzerland). 15 (2015) 19429–19442.
Quantification of Protease Activity Using a Multiplex Microelectrode Array Sensor
Authors: Anderson Morgan J , Song Yang , Fan Huafang , Wright Jestin Gage , Ren Zhaoyang , Hua Duy H , Koehne Jessica E. , Meyyappan Meyya , Li Jun 
Published: July 2021

Proteases are a class of enzymes responsible for selectively breaking down proteins and thus they are involved in many biological processes ranging from apoptosis to hormone regulation. Overexpression of proteases is often indicative of several health conditions, such as muscle atrophy, bone loss and cancer progression. Consequently, the measurement of protease activity can serve as a biomarker for diagnosis as well as the efficacy of treatment regimens. Developing rapid low-cost techniques that can quantitatively detect multiple proteases is essential for these applications.
Here we show the electrochemical characterization of a microfabricated sensor consisting of nine individually addressable microelectrodes. Subsequently, we demonstrate the application of this microelectrode array for the simultaneous, multiplex detection and quantification of protease activity. To accomplish this, each electrode is functionalized with a specific ferrocene labelled hexapeptide substrate and the electrochemical signal is monitored by AC voltammetry. In the presence of the target protease, the AC voltammetry signal decays as the target protease cleaves the peptide substrate, causing the ferrocene tags to leave the electrode surface. The proteolytic activity is determined by fitting the decay in signal to an exponential curve in accordance with the Michaelis-Menten model of heterogeneous kinetics. Our results show that each electrode of the MEA can be selectively modified with little or no contamination from adjacent electrodes. Additionally, we demonstrate that three different peptide substrates can be simultaneously used to quantify the protease activity of a sample. This microelectrode array sensor will be used to develop a portable instrument to track muscular atrophy progression during long duration space habitation in microgravity and to evaluate potential physiological and pharmaceutical countermeasures.
Development of a Selective Mixed-Potential Ammonia Sensor for Automotive Exhausts
Authors: Nematbakhsh Abkenar Gita , Viricelle Jean-Paul , Rieu Mathilde , Breuil Philippe 
Published: July 2021

One of the most effective technologies in decreasing large-scale NOx emission produced by diesel engine vehicles is Urea-SCR (selective catalytic reduction) system. In order to prevent inducing excessive ammonia to the environment, an NH3 sensor is required at the exit of this system [1, 2]. In this study, highly selective ammonia sensors were developed to detect ammonia emissions from automotive exhaust.
The sensors were fabricated with 8-YSZ electrolyte, a platinum reference electrode and a working electrode of Au-V2O5 (mass ratio 85/15), screen-printed on an alumina substrate. A platinum resistor was printed at the backside of the support to control the sensor temperature. The measured sensor’ response (ΔV) is the potential difference between reference and working electrodes. Figure 1 shows the responses of two identical sensors to 100 ppm CO, NO2, NO and 20 ppm of NH3 at four different temperatures. It can be seen that the sensors respond to all gases at lower temperatures while by increasing temperature to 600°C, the selectivity to NH3 is greatly improved. The selectivity of sensors was also confirmed by testing other possible interfering gases: no responses were observed for 20ppm of hydrogen and 100ppm of a hydrocarbon mixture.
The stability of such sensors was studied at 550°C and 600°C. Since the sensors show no long-term stability at 600°C (electrode degradation), but remain stable at 550 °C, investigations were made to decrease the working temperature while maintaining selectivity. After testing different mass percentages of V2O5 in working electrode, we observed that by increasing this value to 50%, the working temperature of selective ammonia sensors could be decreased to 550°C with stable responses.
Further investigations will be performed in order to gain deeper insight in sensing mechanism of V2O5 based working electrodes, which governs the sensor’s performance.

References
[1] K. Shimizu, I. Chinzei, et al. "Doped-vanadium oxides as sensing materials for high temperature operative selective ammonia gas sensors," Sensors and Actuators B, 141, 2009, pp. 410-416.
[2] M. Van Nieuwstadt, I. Dpadhyay, et al. "Control of Urea SCR Systems for US Diesel Applications" in IFP Energies Nouvelles International Conference, Dearborn, USA, 2011, pp. 655-665.

Figure 1
Nanomaterial-Based Electrochemical Sensors for Environmental and Biomedical Applications
Authors: Qian Lanting , Prins Scott , Chen Aicheng 
Published: July 2021

The rapid growth of pharmaceutical industries has led to new biomedical and environmental concerns. There is an urgent need for sensitive, portable and cost-effective sensors for the detection of pharmaceuticals to either track patient overdosing or to monitor the pollutants in the environment. Nanomaterial-based electrochemical sensing technologies can readily tackle the aforementioned problems, which spurred significant research interests recently [1-3]. In this presentation, the synthesis of nanoporous gold and graphene oxide-based nanomaterials for the electrochemical sensing of acetaminophen, naproxen and isoniazid is discussed. The design rationale and the performance of the proposed electrochemical sensors are highlighted. Specifically, the hierarchical nanoporous gold exhibited high sensitivity of 58.16 µAµM−1cm−2 and a low detection limit of 1.01 nM. In addition, it was found that the oxygen content of the graphene-based nanomaterials played a critical role in both sensing of naproxen and isoniazid. The proposed electrochemical sensors were further tested using real samples, which showed their promising applicability in biomedical and environmental applications.
[1] J. van der Zalm, S. Chen, W. Huang, and A, Chen, J.
Electrochem. Soc.,
167
,037532 (2020).
[2] L. Qian, S. Durairaj, S. Prins, and A. Chen, Biosens. Bioelectron., 112836 (2020).
[3] L. Qian, A.R. Thiruppathi, R. Elmahdy, J. van der Zalm, and A. Chen, Sensors.,
20,1252 (2020).
Chemosensor Based on Molecularly Imprinted Nanoparticles for Selective Determination of Glyphosate
Authors: Lach Patrycja , Cieplak Maciej , Garcia Cruz Alvaro Garcia , Canfarotta Francesco , Sharma Piyush Sindhu , Piletsky Sergey A. , Kutner Wlodzimierz 
Published: July 2021

Glyphosate is a commonly used herbicide that can kill some weeds and grasses. Unfortunately, exposure to glyphosate is considered potentially harmful to humans. It may cause liver and kidney damage as well as can affect the endocrine system.1 Furthermore, the International Agency for Research on Cancer considers glyphosate as a probable carcinogen.2 Glyphosate determination often requires additional steps allowing quantification by commonly employed chromatographic techniques. Therefore, low-cost, rapid, and reliable ways to determine this pesticide are essential.
We devised and fabricated an electrochemical chemosensor for the selective determination of the target toxin, glyphosate. As a recognition unit in this sensor, electroactive molecularly imprinted nanoparticles (nanoMIPs) with an internal redox probe were used.3 The MIP nanoparticles were synthesized using a solid-phase synthesis protocol.4 The nanoMIPs were characterized by several methods, including dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The obtained nanoparticles were covalently immobilized on screen-printed platinum electrodes and successfully used for electrochemical determination of glyphosate in the absence of any external redox probe. Chemosensor fabricated that way demonstrated high sensitivity and selectivity with respect to structural analogs of glyphosate and other phosphate-containing analytes. The practical application of this self-reporting MIP-based chemosensor for detecting pesticide was further verified in river water samples with satisfying results. These results prove that our sensor's detectability is sufficient for the on-site detection of glyphosate pesticide.
References:
1 Myers, J. P., Antoniou, M. N., Blumberg, B. et al. Concerns over use of glyphosate-based herbicides and risks associated with exposures: a consensus statement. Environ Health. 15, 19 (2016)
2 Guyton, K. Z., Loomis, D., Grosse, Y. et al. International Agency for Research on Cancer Monograph Working Group ILF. Carcinogenicity oftetrachlorvinphos, parathion, malathion, diazinon, and glyphosate. Lancet Oncol. 16, 490-491 (2015)
3 Cruz, A. G., Haq, I., Cowen, T. et al. Design and fabrication of a smart sensor using in silico epitope mapping and electro-responsive imprinted polymer nanoparticles for determination of insulin levels in human plasma. Biosens. Bioelectron.
169, 112536 (2020)
4 Canfarotta, F., Poma, A., Guerreiro, A. et al. Solid-phase synthesis of molecularly imprinted nanoparticles. Nat Protoc
11, 443–455 (2016)
Leveraging Preconcentration and Partial Separations with Silicon Nanowire Arrays to Improve the Detection of Low Volatility Trace Explosive Vapors
Authors: Giordano Braden , Mullen Matthew , Johnson Kevin , Ratchford Daniel , Giles Spencer , Ryan Justin 
Published: July 2021

Trace detection of explosive vapors in real world environments is hindered by strict sensitivity and selectivity requirements that need to be met in order for these techniques to be effective. The physical properties of most explosive molecules limit environmentally relevant vapor concentrations to the part per billion (ppbv) – part per trillion (pptv) range due to their saturated vapor pressures under real world conditions. Additionally, trace explosive vapor detectors must be able to discriminate against a number of potential chemical and biological interferents present in complex real world environments. In this work, we present silicon nanowire arrays (SiNW) as a novel tunable material aimed at providing trace explosive vapor detectors with the sensitivity and selectivity necessary for operational use.
Dense, highly ordered silicon nanowires are fabricated through a nanosphere lithography process and topped with a porous gold electrode resulting in a high surface area adsorptive substrate intrinsically capable of rapid, precise temperature control via Joule heating. Explosive vapors are selectively preconcentrated onto the SiNW array by exploiting their affinities for the surface (SiO2 or otherwise functionalized) of the nanowires. Chromatographic like partial separations of preconcentrated material on the array can be achieved through careful selection of desorption parameters. Using a multichannel detector, such as an IMS or MS, we demonstrate the preconcentration of a number of explosive vapors including 2,6-DNT, TNT, and RDX, while simultaneously exploring the effects of desorption flow rates and temperatures on the partial separation of 2,6-DNT, 2,4-DNT, TNT, and RDX vapors. In addition, we provide a strategy for chemometric deconvolution of array-based partial separations based upon evolving factor analysis and multivariate curve resolution by alternating least squares. This approach enabled qualitative and quantitative analysis of individual components without target analyte libraries or complete chromatographic separation.