This paper describes the development of a monitoring system capable of detecting the concentration of magnesium ions(Mg^(2+)) released during the degradation of magnesium implants. The system consists of a microdialys...This paper describes the development of a monitoring system capable of detecting the concentration of magnesium ions(Mg^(2+)) released during the degradation of magnesium implants. The system consists of a microdialysis probe that samples fluid adjacent to the implant and a catalytic biosensor specific to Mg^(2+)ions. The biosensor was fabricated on a cotton fabric platform, in which a mixture of glycerol kinase and glycerol-3-phosphate oxidase enzymes was immobilized on the fabric device via a simple matrix entrapment technique of the cotton fibers. Pure magnesium was used as the implant material. Subsequently, the concentration of ions released from the degradation of the magnesium specimen in Ringer's solution was evaluated using cyclic voltammetry technique. The device demonstrated a pseudo-linear response from 0.005 to 0.1 mmol L^(-1) with a slope of 67.48 μA mmol^(-1) L. Detectable interfering species were lesser than 1%indicating a high selectivity of the fabric device. Furthermore,the device requires only 3 μL of fluid sample to complete the measurement compared to spectroscopic method(±50 μL),hence providing a higher temporal resolution and reduced sampling time. The system could potentially provide a real time assessment of the degradation behavior, a new studied aspect in biodegradable metals research.展开更多
This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication tec...This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.展开更多
基金supported by the Malaysian Ministry of Educationthe Natural Sciences and Engineering Research Council of Canada (NSERC)
文摘This paper describes the development of a monitoring system capable of detecting the concentration of magnesium ions(Mg^(2+)) released during the degradation of magnesium implants. The system consists of a microdialysis probe that samples fluid adjacent to the implant and a catalytic biosensor specific to Mg^(2+)ions. The biosensor was fabricated on a cotton fabric platform, in which a mixture of glycerol kinase and glycerol-3-phosphate oxidase enzymes was immobilized on the fabric device via a simple matrix entrapment technique of the cotton fibers. Pure magnesium was used as the implant material. Subsequently, the concentration of ions released from the degradation of the magnesium specimen in Ringer's solution was evaluated using cyclic voltammetry technique. The device demonstrated a pseudo-linear response from 0.005 to 0.1 mmol L^(-1) with a slope of 67.48 μA mmol^(-1) L. Detectable interfering species were lesser than 1%indicating a high selectivity of the fabric device. Furthermore,the device requires only 3 μL of fluid sample to complete the measurement compared to spectroscopic method(±50 μL),hence providing a higher temporal resolution and reduced sampling time. The system could potentially provide a real time assessment of the degradation behavior, a new studied aspect in biodegradable metals research.
基金This work was supported by the Czech Science Foundation(GAČR,No.22-14886S)the MCIN/AEI/10.13039/501100011033(No.PID2019-107697RBC42(ERDF A way of making Europe)).
文摘This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.
