Electrochemical Impedance Spectroscopy Based Biosensors: Mechanistic Principles, Analytical Examples and Challenges towards Commercialization for Assays of Protein Cancer Biomarkers

Impedimetric affinity biosensors are, without any doubt, among the most sensitive analytical devices available, offering low limits of detection and wide linear response ranges. There are, however, only a few papers detailing the application of impedimetric biosensors for the analysis of clinically relevant samples with due clinical performance. The fact that these devices have not found their way to any commercial or clinical use to date might be surprising, since an electrochemical assay platform based on portable potentiostats is a success story for monitoring a range of clinical parameters such as ions, haematological indicators and glucose. This review discusses the reasons behind this discrepancy and addresses the barriers to be overcome in order to achieve the point-of-care diagnostics using such devices for detection of protein oncomarkers approved by FDA. The final part of the review covers the most recent progress in the area.The financial support received from the Slovak Scientific Grant Agency VEGA 2/0137/18 and 2/0090/16 and the Slovak Research and Development Agency APVV 17-0300 and APW-15-0227 is acknowledged. The research received funding from the European Research Council (no. 311532). This publication is the result of the project implementation: Centre for materials, layers and systems for applications and chemical processes under extreme conditions - Stage I, ITMS No.: 26240120007, supported by the ERDF

Mitigation pathways of air pollution from residential emissions in the Beijing-Tianjin-Hebei region in China

Air pollution is one of the most harmful consequences of China's rapid economic development and urbanization. Particularly in the Beijing-Tianjin-Hebei (BTH) regions, particulate matter concentrations have consistently exceeded the national air quality standards. Over the last years, China implemented ambitious measures to reduce emissions from the power, industry and transportation sectors, with notable success during the 11th and 12th Five Year Plan (FYP) periods. However, such strategies appear to be insufficient to reduce the ambient PM2.5 concentration below the National Air Quality Standard of 35 μg m−3 across the BTH region within the next 15 years. We find that a comprehensive mitigation strategy for the residential sector in the BTH region would deliver substantial air quality benefits. Beyond the already planned expansion of district heating and natural gas distribution in urban centers and the foreseen curtailment of coal use for households, such a strategy would redirect some natural gas from power generation units towards the residential sector. Rural households would replace biomass for cooking by liquid petroleum gas (LPG) and electricity, and substitute coal for heating by briquettes. Jointly, these measures could reduce the primary PM2.5 and SO2 emissions by 28% and 11%, respectively, and the population-weighted PM2.5 concentrations by 13%, i.e., from 68 μg m−3 to 59 μg m−3. We estimate that such a strategy would reduce premature deaths attributable to ambient and indoor air pollution by almost one third

Optimizing web services performance by using similarity-based multicast protocol

Web services have emerged as a key technology that enables interoperability between distributed applications. It is desirable that SOAP, being the Web service transport protocol for interconnecting applications across organizations, performs efficiently in environments where there are a large number of transactions. This paper presents a novel approach to address this issue and hence improve Web services performance. We propose a similarity-based SOAP multicast protocol (SMP) that reduces the network load by optimizing the generated traffic size. In particular, SMP reuses the common template among the SOAP messages and only sends one copy of the common part to multiple clients. The results obtained from our experiments indicate that SMP achieved a 75 percent reduction in network traffic compared to traditional SOAP unicas

eSMP: A multicast protocol to minimize SOAP network traffic in low bandwidth environments

Web services, which are built on SOAP as the transport protocol, have emerged in recent years as a promising technology to enable interoperability between distributed applications. As such, SOAP may be used to handle a large number of transactions; and consequently it is desirable to have SOAP perform efficiently in high traffic environments. This paper presents eSMP, an extension of our previous work on a similarity-based SOAP multicast protocol (SMP). eSMP offers improvements over SMP in terms of traffic size by using its own routing protocol instead of the conventional shortest path algorithm to route messages to paths that will minimize the number of bytes transmitted in the network. From extensive experiments, it is shown that eSMP achieves a minimum of 25 percent reduction in total network traffic than SMP with a tradeoff of 10 percent increase in average response time. Compared to unicast, bandwidth consumptions can by reduced by up to 80 percent when using eSMP and 70 percent when using SMP. Therefore, eSMP is suitable for applications where bandwidth requirement is critical but not time

Nanoscale-controlled architecture for the development of ultrasensitive lectin biosensors applicable in glycomics

In this mini-review the most advanced patterning protocols and transducing schemes for the development of ultrasensitive label-free and label-based lectin biosensors for the glycoprofiling of disease markers and some cancerous cells are described. The performance of such lectin biosensors with interfacial properties tuned to the nanoscale are critically compared to the most sensitive immunoassay format of analysis, and challenges for the future are discussed. In addition the key elements for further development of these devices are considered, with a view to improvement of their robustness and practical applicability.APVV 0282-11 and VEGA 2/0162/14 provided by the Slovak grant agencies. European Research Council (ERC Grant Agreement No. 311532) and from the European Union Seventh Framework Program (FP/2007�2013 with Grant Agreement No. 317420). NPRP grant 6-381-1-078 from the Qatar National Research Fund (a member of the Qatar Foundation).Scopu

Sensitive detection and glycoprofiling of a prostate specific antigen using impedimetric assays

This study presents a proof-of-concept for the development of an impedimetric biosensor for ultra-sensitive glycoprofiling of prostate specific antigen (PSA). The biosensor exhibits three unique characteristics: (1) analysis of PSA with limit of detection (LOD) down to 4 aM; (2) analysis of the glycan part of PSA with LOD down to 4 aM level and; (3) both assays (i.e., PSA quantification and PSA glycoprofiling) can be performed on the same interface due to label-free analysis.The financial support received from the Slovak Scientific Grant Agency VEGA 2/0162/14 and 1/0229/12; and from the Slovak Research and Development Agency APVV 0282-11 is acknowledged. This report was made possible by a NPRP award [NPRP grant no. 6-381-1-078] from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors. The research leading to these results received funding from the European Research Council under the European Union?s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 311532 and this work has received funding from the European Union?s Seventh Framework Program for research, technological development and demonstration under grant agreement no. 317420. This publication is the result of the project implementation: Centre for materials, layers and systems for applications and chemical processes under extreme conditions ? Stage I, ITMS No.: 26240120007 supported by the Research & Development Operational Programme funded by the ERDF.Scopu

On the equivalence of direct mechanisms and structurally minimal pathways

A reaction‐pathway identification procedure has two distinct phases. The first phase enumerates exhaustively the feasible candidate pathways, and the second phase identifies the ultimate feasible pathway or pathways among them. Probably the most efficient way to execute the first phase is to algorithmically generate the networks of feasible candidate pathways from a predefined set of plausible elementary reactions. The available algorithmic methods for this purpose can be roughly grouped into two major classes, one based on graph theory and the other on linear algebra. Both classes of methods consider any chemical reaction system as a network of elementary reactions, thereby implying that the two classes are interrelated. This paper studies the linear algebraic concept termed direct mechanism introduced in the mid‐eighties and the graph‐theoretical concept termed structurally minimal pathway introduced two decades later. Herein, it has been formally proven that the two concepts are equivalent