bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Mechanism Insight for Enhanced Electrochemiluminescence Signal
Authors: Valenti Giovanni , Zanut Alessandra , Fiorani Andrea , Marcaccio Massimo , Rapino Stefania , Paolucci Francesco 
Published: July 2021

Electrochemiluminescence (ECL) is a leading technique in bioanalysis.[1] Since the excited species are produced with an electrochemical stimulus rather than with a light excitation source, ECL displays improved signal-to-noise ratio compared to photoluminescence, with minimized effects due to light scattering and luminescence background. The most challenging breakthrough in the development of analytical electrochemiluminescence (ECL) applications was reported from Bard and co workers that presented for the first time the generation of ECL with a coreactant.[1] This finding opened the application of ECL to large literature and transformed ECL from an academic curiosity to a real application and industrial success. In this context, the only real used materials for the ECL analytical and commercial application are tripropylamine (TPrA) as sacrificial ”oxidative-reductant” coreactant and Ruthenium(II)-tris(2,2’-bipyridine) ([Ru(bpy)3]2+) as emitting species. In this case the mechanism for the ECL generation was proposed by Bard and still nowadays the only one accepted.[2],[3]
Here we show an additional, and very efficient, mechanism pathway for the generation of ECL by using TPrA as coreactant. Thanks to the combination between ECL and microscopy we experimentally prove the alternative mechanism with the standard [Ru(bpy)3]2+/TPrA system.[3],[4] These mechanistic findings allow us to propose alternative amines as coreactant enhancing the ECL signal of more than one order of magnitude.
The reported results, besides contributing to a better understanding of the mechanisms operating in the chemiluminescence generation, also pave the way for the development of very highly efficient ECL coreactants for ultrasensitive bioanalysis.[5]
[1] Miao W.; Choi J. P.; Bard A. J., J. Am. Chem. Soc.
2002, 124, 14478-14485
[2] Sentic M.; Milutinovic M.; Kanoufi F.; Manojlovic D.; Arbault S.; Sojic N., Chem. Sci.
2014, 5, 2568-2572
[3] Valenti G.; Scarabino S.; Goudeau B.; Lesch A.; Jović M.; Villani E.; Sentic M.; Rapino S.; Arbault S.; Paolucci F.; Sojic N., J. Am. Chem. Soc.
2017, 139, 16830-16837.
[4] a) Valenti G.; Zangheri M.; Sansaloni S. E.; Mirasoli M.; Penicaud A.; Roda A.; Paolucci F., Chem. Eur. J., 2015, 21, 12640–12645; b) Zanut A.; Fiorani A.; Rebeccani S.; Kesarkar S.; Valenti G., Anal. Bioanal. Chem., 2019, 411(19), 4375-4382.
[5] Zanut A. at al Nature Commun. 2020, 11, 2668

Figure 1
Amplification-Free Electrochemiluminescence Molecular Beacon-Based microRNA Sensing Using a Mobile Phone for Detection
Authors: Kerr Emily , Henderson Luke , Hayne David J , Farr Ryan , Dearnley Megan , Doeven Egan H , Alexander Richard , Guijt Rosanne M , Nai Yi Heng , Prieto-Simon Beatriz , Francis Paul S , Voelcker Nicolas 
Published: July 2021

The burgeoning field of miRNA detection using electrochemiluminescence (ECL) has garnered a great deal of attention in recent times.1 ECL presents many advantages over alternative detection strategies as ECL analyses generally exhibit low-background signals, high sensitivity, are reproducible and scale-able.2 When combined with magnetic-beads for the immobilisation of biological recognition elements, ECL biosensors offer exceptional sensitivity owing to the ability to disperse the beads in large sample volumes to capture the biological target of interest via mixing then concentrate prior to analysis via magnetic extraction.3, 4

Herein, we present a novel biosensor for the sensitive detection of miRNA-21 comprising a molecular beacon ECL probe immobilised on magnetic beads. We obtained a limit of detection of 500 attomoles for miRNA-21 without enzymatic amplification or the addition of detection probes or intercalating labels, negating the need for lengthy and stringent washing procedures to reduce the background signal. Furthermore, we demonstrate the immense potential for point-of-care applications by developing a fully integrated miRNA detection platform. The platform comprises a portable potentiostat for ECL generation, mobile phone for ECL detection and a custom 3D-printed cell holder to readily interface a disposable screen-printed electrode with the potentiostat and mobile phone.
We applied our magnetic miRNA extraction technology to the detection of miRNA-21, a promising biomarker for the early diagnosis of chronic kidney disease, in human urine RNA extracts.5 Urine is an ideal sample matrix as it is non-invasive to obtain in large volumes, does not require a phlebotomist to acquire and miRNAs in urine are stable in exosomes. When combined with point-of-care miRNA extraction methods, the molecular beacon based ECL system we have developed presents a promising tool for point-of-care diagnosis and management of numerous diseases.
References

P. K. Kalambate, N. S. Gadhari, X. Li, Z. Rao, S. T. Navale, Y. Shen, V. R. Patil and Y. Huang, TrAC, Trends Anal. Chem., 2019, 115643.

Y. Cheng, L. Dong, J. Zhang, Y. Zhao and Z. Li, Analyst, 2018, 143, 1758-1774.

M. H. Shamsi, K. Choi, A. H. Ng, M. D. Chamberlain and A. R. Wheeler, Biosens. Bioelectron., 2016, 77, 845-852.

W. Liu, X. Zhou and D. Xing, Biosens. Bioelectron., 2014, 58, 388-394.

M. L. Alvarez, M. Khosroheidari, R. Kanchi Ravi and J. K. DiStefano, Kidney Int., 2012, 82, 1024-1032.
Light-Addressable Potentiometric Aptasensor for Label-Free Detection of Marine Toxin
Authors: Tian Yu-lan , Zhu Ping , Chen Ya-ting , Du Li-ping , Chen Wei , Wu Chunsheng , Wang Ping 
Published: July 2021

Okadaic acid (OA) is one of the most common marine toxins, which can cause human poisoning or even death. It is desirable and essential to develop novel approaches for OA detection in a convenient, practical and low-cost manner. In this study, a novel light-addressable potentiometric aptasensor was designed for label-free detection of OA. The aptamers specifically binding with OA were used as the sensing elements, light-addressable potentiometric sensor (LAPS) chip was used as the transducer, LAPS detection and imaging system was constructed for signal detection. The results showed that this biosensor had high sensitivity and specificity for the detection of OA. The research on this biosensor provides a novel approach for inexpensive, rapid, ultrasensitive, highly specific and label-free detection of OA as well as other marine biological toxins.
keywords: Biosensor; LAPS; Aptamer; OA
Low-Frequency and High-Frequency Modulation of the Local Field Potential Spectrum of Genetically Engineered Rats Induced By Odor Stimuli
Authors: Zhu Ping , Tian Yu-lan , Liu Shu-ge , Chen Ya-ting , Chen Wei , Du Li-ping , Wu Chunsheng 
Published: July 2021

The local field potential (LFP) oscillations of the olfactory bulb are regulated by odor stimulation, and the mechanism of this regulation supports the causal relationship between LFP oscillations and odor recognition. We tested the neuronal activity and LFP oscillation of the mitral/tufted cells in olfactory bulb of rats overexpressing the olfactory receptor OR3 under the stimulation of ligand odor. We found that compared with non-ligand odor, OR3 ligand odor stimulus changed the oscillating power of beta band and gamma band in a part of M/T cells, and affected the phase synchronization of spikes activity and LFP of M/T cells. These results indicate that the genetically engineered rats are more sensitive to odors, and the synchronization of spike activity and LFP oscillations may affect neural coding.
Key words: olfactory system; odor detection; genetic engineering; local field potential; neural oscillation
Electrochemical Competitive Magneto-Immunoassay for Determination of Neurotoxin Domoic Acid
Authors: Weber Michael , Fanjul Pablo , Izquierdo-Bote Daniel , González-García María Begoña , Hernández-Santos David 
Published: July 2021

Domoic acid is heterocyclic amino acid neurotoxin and the principal toxin associated with amnesic shellfish poisoning (ASP) produced by certain species of marine diatom. It can bio accumulated at high concentrations in the shellfish tissues when the toxic phytoplankton is high in concentration in the surrounding waters. Ingestion of domoic acid contaminated shellfish leads to ASP, which is characterized by both gastrointestinal and neurological symptoms, including severe headache, seizures, tremors, and either temporary or permanent memory loss.
Herein, the detection of domoic acid is carried out through an enzymatic immunoassay that uses magnetic beads as support of the immunoreaction and screen-printed electrodes as suitable detector of the enzymatic product. Thereby, the immunological reaction is performed in solution, where the domoic acid, antigen, domoic acid labeled with horseradish peroxidase are incubated with the rabbit IgG antibody against domoic acid. Subsequently, the antibody-antigen complex is captured by the anti-rabbit IgG modified magnetic beads. Then, the magnetic beads are deposited onto the electrode surface with the help of the magnet placed under the screen printed electrode. Finally, the analytical signal is obtained by amperometric detection of the product enzymatically generated from the mixture of H2O2and 3,3,5,5-tetramethylbenzidine (TMB).
The use of magnetic beads provides the capability to preconcentrate the sample and avoid the poisoning of the electrode surface through non specific absorptions.
The experimental conditions of the magneto-immunological assay has been optimized and a calibration curve has been obtained between 0-2 ng/mL domoic acid, being able to detect down to 100 pg/mL domoic acid.

Acknowledgements

This work has been carried out in the framework of FLAshMoB project. This project is funded by the MarTERA partners; Italian Ministry of Education, Universities and Research (MIUR), French National Research Agency (ANR) and Spanish Centre for the Development of Industrial Technology (CDTI) and co-funded by the European Union.
Glucose Detection Using Molecularly Imprinted Mesoporous Organosilica
Authors: Jimenez-Monroy Kathia , Caldara Manlio , Eersels Kasper , Diliën Hanne , van Grinsven Bart , Cleij Thomas J. 
Published: July 2021

Since the first developments in Molecular Imprints, the general approach is to crosslink a polymeric network around a target molecule, which serves as a template. After removing the target imprint, the remaining polymer keeps the shape and functional groups for rebinding with the target molecule. Therefore, Molecularly Imprinted Polymers (MIPs) are also known as artificial antibodies.
In the context of sensing applications, the advantages of using MIPs over natural antibodies range from higher stability at different measuring conditions (eg. solvents, pH, etc.) to longer shelf-life. However, the hydrophobic nature of polymers might play a role in the sensitivity of measurements performed in aqueous solvents, for example to detect contaminants in food samples.
To tackle this problem, we use hydrophilic mesoporous organosilica polymers to detect glucose in real time. Sensitivity and selectivity tests were performed using the developed organosilica MIP and the corresponding Non-Imprinted Polymer (NIP). Rebinding isotherms were calculated using uv-vis spectroscopy, Impedance and Heat-transfer method (HTM).
Multiplexed Bioanalysis Based on Light-Sensitive Electrodes
Authors: Zhao Shuang , Riedel Marc , Yue Zhao , Parak Wolfgang , Lisdat Fred 
Published: July 2021

Introduction
Quantum dots (QDs) have become attractive tools in bioanalysis because of their advantageous optical and electrochemical properties. This relates to applications exploiting fluorescence, electrochemiluminescence or photocurrent generation [1]. For the latter case QDs are immobilized on conductive electrodes. By light excitation charge carriers are formed inside the nanoparticles which can be used for photocurrent generation. Signal chains can be constructed when appropriate donor or acceptor components are present in solution. The special feature of such electrodes is that the response is triggered by illumination of the sensing electrode [1]. In this study, a light-addressable photoelectrochemical sensor was built by coupling QDs with oxidases to detect different enzyme substrates.
Results and Conclusions
First CdSe/ZnS QDs have been immobilised via a dithiol compound on gold electrodes. Two different enzymes, glucose oxidase (GOD) and sarcosine oxidase (SOD) have been deposited on this QDs-electrode at spatially well resolved places. Here small spots have been achieved by a dropping method. A laser beam is moved over the spots to detect photocurrents. Since oxygen can act as electron acceptor at the illuminated QDs the photocurrent is correlated to the oxygen concentration in solution. By action of the enzymes in the presence of the corresponding substrate a competitive situation for oxygen is created in front of the QD layer and thus, the photocurrent decreases [2, 3]. Since this happens in a concentration dependent way, analysis of the enzyme substrate is feasible.
Furthermore, due to the spatially separated immobilisation of the two enzymes, an independent read-out of the two enzyme reactions is possible. The results indicate good lateral resolution and selectivity of the multi-detection system without any crosstalk between the two sensing regions and also without any response at regions, which have not been modified with an enzyme [4].
After that, the possibility of an imaging of the enzyme spot by photocurrent measurement has been studied. When the laser is moved over the spot of GOD with a constant speed, the size of the spot can be determined from the photocurrent - time curve (with a defined moving speed). The photocurrent correlates to different local enzyme activities. Consequently, an imaging of the enzyme activity distribution on the surface has also been achieved by this method.
References
[1] F. Lisdat, D. Schäfer, A. Kapp, Analytical and Bioanalytical Chemistry 405 (2013) 3739-3752
[2] M. Riedel, et al., Chem. Phys. Chem. 2013, 14, 2338-2342.
[3] J. Tanne et al., Anal. Chem. 2011, 83, 7778-7785.
[4] S. Zhao et al., ACS Applied Materials & Interfaces, 2019, Vol. 11 (24), p. 21830-21839
Soft Electrochemical/Electronic Devices and Their Applications in Point-of-Care Testing
Authors: Li Fei 
Published: July 2021

Using soft materials (e.g., paper, hydrogel) to replace the traditional hard materials (e.g., glass, silicon) as substrates have become a recent trend in developing point-of-care testing (POCT) platforms. And through integration of the soft materials with electrochemical or electric devices can further extend the applications of POCT. In our recent work, we used four kinds of soft materials, including paper, PDMS, hydrogel and liquid marble, as the new soft substrates of POCT platforms and realized their new applications in POCT. For example, by integration of the electrodes and hydrophobic channels on paper through simply writing method using home-made pens, the fabricated paper-based electrochemical devices have been successfully applied to detect glucose in artificial urine and melamine in sample solutions. By fabrication of MWNTs/PDMS fibers as multifunctional sensors and integration them on a glove, the measurement of gesture recognition and temperature have been realized by the “smart” glove. Through injection of liquid metal into the 3D helical structure of hydrogel and combination the hydrogel with electronic sensing device, the temperature, UV sensing and EMG signal detections have been performed by the wearable, multifunctional hydrogel device. By using liquid marble as a separator and small device for isoelectric focusing, the POCT separation and analysis of proteins have been realized. The proposed new soft platforms show wide application potential in POCT.

References

[1] J. C. Niu, H. X. Shi, H. G. Wei, B. Gao, J. Li, F. Xu, X. G. Li, F. Li, Liquid Plasticine Integrated with Isoelectric Focusing for Miniaturized Protein Analysis, Analytical Chemistry. 2020, 92, 9048
[2] H. Liu, M. X. Li, S. B. Liu, P. P. Jia, X. J. Guo, S. S. Feng, T. J. Lu, H. Y. Yang, F. Li, F. Xu, Spatially Modulated Stiffness on Hydrogel for Soft and Stretchable Integrated Electronics, Material Horizons. 2020, 7, 203
[3] Z. D. Li, H. Liu, X. C. He, F. Xu, F. Li, Pen-on-Paper Strategies for Point-of-Care Testing of Human Health, Trac-Trends Anal. Chem. 2018, 108, 50.
Nanostructured Molecular Imprinted Polymers for Chemosensing of Hormone Proteins
Authors: Kalecki Jakub , Cieplak Maciej , Dąbrowski Marcin , Lisowski Wojciech , Kuhn Alexander , D'Souza Francis , Sharma Piyush Sindhu 
Published: July 2021

Immunoassays and high-performance liquid chromatography combined with mass spectrometry are common methods to selectively determine protein biomarkers in biological samples. The excellent accuracy of these determinations is at the expense of a high cost, including the cost of specific antibodies supply or instrumentation and experienced operation. Several biosensors were devised and fabricated for fast and selective quantification of the protein biomarkers. The most interesting protein biomarkers belong to the glycoprotein family. Unfortunately, it seems challenging to generate antibodies for this family because of low immunogenicity. Thus, an alternative research field is developing which claims to synthesize more stable artificial antibody-like receptors for the replacement of natural antibodies.
Here, a semi-covalent procedure is proposed to elaborate surface imprinted polymers for selective recognition of gonadotropin hormones.1,2 Briefly, this strategy consists of a combination of three methods, namely, (i) lithography, (ii) surface imprinting, and (iii) semi-covalent imprinting. Hard template silica beads were used as a mold to prepare a highly organized opal structure. On top of this, template proteins were immobilized. Later, the protein was derivatized with functional monomers. These functionalized template molecules were electrochemically cross-linked with an excess of cross-linking monomer. Removal of the silica mold creates a nanostructure containing molecular cavities on the surface. Such nanostructures are advantageous for non-restrictive diffusion of bulky proteins toward the respective molecular cavities.
We confirmed regular and hexagonal packing of silica beads, resulting in inverse opal surface imprinted molecular films, by Scanning Electron Microscope (SEM). The recognition of proteins by the nanostructured molecular imprinted polymer films was transduced with the help of capacitive impedimetry. The suitability of the synthetic receptor was further confirmed by measuring proteins in real blood serum samples.
References
[1] J. Kalecki, M. Cieplak, M. Dąbrowski, W. Lisowski, A. Kuhn, P. S. Sharma, ACS Sens.
2020, 5, 1, 118.
[2] M. Dabrowski, A. Zimińska, A., J. Kalecki, M. Cieplak, W. Lisowski, W. R. Maksym, S. Shao, F. D'Souza, A. Kuhn, P. S. Sharma, ACS Appl. Mater. Interfaces. 2019, 11, 9265.

Acknowledgements

The present research was financially supported by the Polish National Science Centre (Grant No. NCN 2017/25/B/ST4/01696 to P.S.S.).

Figure 1
Surface-Modified Mxene Nanosheets to Enable Complete Utilization and Immobilization of Polysulfides in Lithium-Sulfur Batteries
Authors: Pai Rahul , Natu Varun , Sokol Maxim , Carey Michael , Barsoum Michel W. , Kalra Vibha 
Published: July 2021

Lithium-Sulfur batteries are of great interest owing to sulfur's high theoretical capacity, low-cost and environmental benignity. However, the practicality of these batteries has been impeded due to the infamous “polysulfide-shuttle” effect. Although several research articles in the past decade have focused to mitigate this effect, capacity fade and low coulombic efficiency still prevail. 2D MXenes are early transition metal carbides known for their high metallic conductivity with tunable surface functionalities. MXenes with formula Mn+1XnTx are usually derived from the parental MAX phases by selectively etching the A layer (where M represents a transition metal, A represents the group 13 or 14 elements in the periodic table and X represents carbon or nitrogen, Tx stands for the surface terminations). Thus, the obtained MXenes possess a unique layered structure. After etching, the surface of MXenes is terminated with various functional groups such as hydroxyl (-OH), oxygen (-O), chlorine (-Cl), and fluorine (-F).
Rich surface polar sites in Ti3C2Tx enhance electrochemical performance via suppression of polysulfide shuttle. However, past synthesis procedures result in the development of hydrophilic MXene nanosheets unable to be coupled with hydrophobic sulfur. Herein, we propose a new design based on the functionalization of MXene nanosheets with an organic molecule for the effective deposition of sulfur nanoparticles on the surface. This strategy enables the dispersion of MXene sheets in sulfur dissolved solvents enabling the conformal deposition of sulfur on MXene sheets with negligible water in the composite. The metallic sheet-like conductivity (~103 S.cm-1) also aids in faster reaction kinetics during the conversion of polysulfides to Li2S, mitigating the shuttle effect. Consequently, the developed composite enables the efficient utilization of active surface sites to bind polysulfides and alleviate the shuttle effect. This novel cathode delivers a high initial reversible capacity of 1220 mAh·g-1 at 0.1 C and at 0.5C, these cathodes stabilize at 880mAh·g-1 after the first 5 cycles, 85% of which is retained post 500 cycles. Additionally, we developed cathodes with high sulfur loading of ~10.7 mg·cm-2 that delivers a stable areal capacity of ~7 mAh·cm-2 for 150 cycles. Moreover, these cathodes in a pouch cell configuration retained ~770 mAh·g-1 after ~200 cycles at 0.2C (85.5% retention). Ex-situ studies elucidated the nature of the LiPs–MXene interaction and the effect of surface functionalization towards improved performance

+RP and VN have equal contribution