scholarly journals Microfluidic Adsorption-Based Biosensors: Mathematical Models of Time Response and Noise, Considering Mass Transfer and Surface Heterogeneity

2021 ◽  
Author(s):  
Ivana Jokić
Keyword(s):  
Mass Transfer ◽  
Mathematical Models ◽  
Surface Heterogeneity ◽  
Time Response ◽  
Sensor Performance ◽  
Surface Areas ◽  
Microfluidic Chamber ◽  
Analyte Detection ◽  
Adsorption Desorption ◽  
Sensing Performance

Adsorption-based microfluidic sensors are promising tools for biosensing. Advanced mathematical models of time response and noise of such devices are needed in order to improve the interpretation of measurement results, and to achieve the optimal sensor performance. Here the mathematical models are presented that take into account the coupling of processes that generate the sensor signal: adsorption–desorption (AD) of the target analyte particles on the heterogeneous sensing surface, and mass transfer (MT) in a microfluidic chamber. The response kinetics and AD noise (which determines the ultimate sensing performance) of protein biosensors are analyzed, assuming practically relevant analyte concentrations, sensing surface areas and MT parameters. The condition is determined under which MT significantly influences the sensor characteristics relevant for reliable analyte detection and quantification. It is shown that the development of improved mathematical models of sensor temporal response and noise can be used as one of strategies for achieving better sensing performance.

scholarly journals Analysis of Stochastic Time Response of Microfluidic Biosensors in the Case of Competitive Adsorption of Two Analytes

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 991
Author(s):  
Ivana Jokić ◽  
Zoran Djurić ◽  
Katarina Radulović ◽  
Miloš Frantlović
Keyword(s):  
Mass Transfer ◽  
Competitive Adsorption ◽  
Sensor Response ◽  
Time Response ◽  
Response Model ◽  
Desorption Process ◽  
Complex Samples ◽  
Low Concentrations ◽  
Adsorption Desorption ◽  
Stochastic Time

A model of stochastic time response of adsorption-based microfluidic biosensors is presented, that considers the competitive adsorption-desorption process coupled with mass transfer of two analytes. By using the model we analyze the expected value of the adsorbed particles number of each analyte, which determine the sensor response kinetics. The comparison with the case when only one analyte exists is used for investigation of the influence of competitive adsorption on the sensor response. The response kinetics analyzed by using the stochastic model is compared with the kinetics predicted by the deterministic response model. The results are useful for optimization of micro/nanosensors intended for detection of substances in ultra-low concentrations in complex samples.

scholarly journals Stochastic Time Response and Ultimate Noise Performance of Adsorption-Based Microfluidic Biosensors

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 194
Author(s):  
Ivana Jokić ◽  
Zoran Djurić ◽  
Katarina Radulović ◽  
Miloš Frantlović ◽  
Gradimir V. Milovanović ◽  
...  
Keyword(s):  
Performance Metrics ◽  
False Negative ◽  
Measurement Data ◽  
Stochastic Approach ◽  
Sensor Response ◽  
Time Response ◽  
Response Analysis ◽  
Noise Performance ◽  
Analyte Detection ◽  
Adsorption Desorption

In order to improve the interpretation of measurement results and to achieve the optimal performance of microfluidic biosensors, advanced mathematical models of their time response and noise are needed. The random nature of adsorption–desorption and mass transfer (MT) processes that generate the sensor response makes the sensor output signal inherently stochastic and necessitates the use of a stochastic approach in sensor response analysis. We present a stochastic model of the sensor time response, which takes into account the coupling of adsorption–desorption and MT processes. It is used for the analysis of response kinetics and ultimate noise performance of protein biosensors. We show that slow MT not only decelerates the response kinetics, but also increases the noise and decreases the sensor’s maximal achievable signal-to-noise ratio, thus degrading the ultimate sensor performance, including the minimal detectable/quantifiable analyte concentration. The results illustrate the significance of the presented model for the correct interpretation of measurement data, for the estimation of sensors’ noise performance metrics important for reliable analyte detection/quantification, as well as for sensor optimization in terms of the lower detection/quantification limit. They are also incentives for the further investigation of the MT influence in nanoscale sensors, as a possible cause of false-negative results in analyte detection experiments.

Methodology of Research in Micropollutants – Heavy Metals

1982 ◽  
Vol 14 (12) ◽  
pp. 107-125 ◽  
Author(s):  
Roland Wollast
Keyword(s):  
Heavy Metals ◽  
Mathematical Models ◽  
Aqueous Phase ◽  
Suspended Matter ◽  
Solid Phase ◽  
Aquatic Organisms ◽  
Biological Processes ◽  
Particulate Phase ◽  
Sources Of Pollution ◽  
Adsorption Desorption

A comparison of the concentration of dissolved and of particulate heavy metals in the aquatic system indicates that these elements are strongly enriched in the suspended matter. The transfer between the aqueous phase and the solid phase may be due to dissolution-precipitation reactions, adsorption-desorption processes or biological processes. When these processes are identified, it is further possible to develop mathematical models which describe the behaviour of these elements. The enrichment of heavy metals in the particulate phase suspended or deposited and in aquatic organisms constitutes a powerful tool in order to evaluate sources of pollution.

Laboratory Experiments of Mass Transfer in the London Clay

1988 ◽  
Vol 127 ◽  
Author(s):  
P. J. Bourke ◽  
D. Gilling ◽  
N. L. Jefferies ◽  
D. A. Lever ◽  
T. R. Lineham
Keyword(s):  
Mass Transfer ◽  
Porous Media ◽  
Radioactive Waste ◽  
Mass Transport ◽  
Mathematical Models ◽  
Laboratory Experiments ◽  
Naturally Occurring ◽  
Diffusion And Convection ◽  
Waste Repository ◽  
London Clay

ABSTRACTAqueous phase mass transfer through the rocks surrounding a radioactive waste repository will take place by diffusion and convection. This paper presents a comprehensive set of measurements of the mass transfer characteristics for a single, naturally occurring, clay. These data have been compared with the results predicted by mathematical models of mass transport in porous media, in order to build confidence in these models.

scholarly journals Acetone Sensing and Catalytic Conversion by Pd-Loaded SnO2

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5921
Author(s):  
Pascal M. Gschwend ◽  
Florian M. Schenk ◽  
Alexander Gogos ◽  
Sotiris E. Pratsinis
Keyword(s):  
Gas Sensors ◽  
Tin Oxide ◽  
Operating Temperature ◽  
Packed Bed ◽  
Sensor Performance ◽  
Response Recovery ◽  
Recovery Times ◽  
Metal Additives ◽  
Metal Oxide Gas Sensors ◽  
Sensing Performance

Noble metal additives are widely used to improve the performance of metal oxide gas sensors, most prominently with palladium on tin oxide. Here, we photodeposit different quantities of Pd (0–3 mol%) onto nanostructured SnO2 and determine their effect on sensing acetone, a critical tracer of lipolysis by breath analysis. We focus on understanding the effect of operating temperature on acetone sensing performance (sensitivity and response/recovery times) and its relationship to catalytic oxidation of acetone through a packed bed of such Pd-loaded SnO2. The addition of Pd can either boost or deteriorate the sensing performance, depending on its loading and operating temperature. The sensor performance is optimal at Pd loadings of less than 0.2 mol% and operating temperatures of 200–262.5 °C, where acetone conversion is around 50%.

Math Modeling of Vacuum Conductive Timber Drying

2014 ◽  
Vol 1040 ◽  
pp. 478-483
Author(s):  
M. Goreshnev ◽  
E. Litvishko
Keyword(s):  
Mathematical Modeling ◽  
Mass Transfer ◽  
Mathematical Models ◽  
Heat And Mass Transfer ◽  
Block Diagram ◽  
Calculated Data ◽  
Math Modeling ◽  
Advantages And Disadvantages ◽  
Transfer Problems

The article is devoted to the mathematical modeling of vacuum conductive timber drying. Analysis of known mathematical models allowed revealing their advantages and disadvantages. The modeling block diagram based on the drying periods is proposed. Lykov’s equations have been selected to solve heat and mass transfer problems. The comparison of experimental and calculated data has been conducted.

Sign in / Sign up

Export Citation Format

Share Document