Conductive polymers have attracted wide attention since their discovery due to their unique prope... more Conductive polymers have attracted wide attention since their discovery due to their unique properties such as good electrical conductivity, thermal and chemical stability, and low cost. With different possibilities of preparation and deposition on surfaces, they present unique and tunable structures. Because of the ease of incorporating different elements to form composite materials, conductive polymers have been widely used in a plethora of applications. Their inherent mechanical tolerance limit makes them ideal for flexible devices, such as electrodes for batteries, artificial muscles, organic electronics, and sensors. As the demand for the next generation of (wearable) personal and flexible sensing devices is increasing, this review aims to discuss and summarize the recent manufacturing advances made on flexible electrochemical sensors
Miniaturized autonomous swimmers have become more and more important in many areas of research du... more Miniaturized autonomous swimmers have become more and more important in many areas of research due to various fields of use, ranging from biomedical to environmental tasks. Precise and predictable control of their trajectories is a key ingredient for increasing their application potential. This can be typically achieved by using external forces such as magnetic or electric fields. An interesting alternative is to use intrinsic features of the swimmers, which allow them to exhibit chemotaxis. Such a built‐in “intelligence” enables more complex trajectories, relying on mechanisms that can be considered very basic analogs of decision‐making processes. Herein, autonomous light‐emitting chemoelectronic swimmers are presented that are able to navigate along trajectories with increasing complexity. Their decision‐making capacities are characterized by recording the light emitted along their path by a fully integrated light‐emitting diode. Chemotaxis is found to be the main driving force be...
Numerous artificial micro- and nanomotors, as well as various swimmers have been inspired by livi... more Numerous artificial micro- and nanomotors, as well as various swimmers have been inspired by living organisms that are able to move in a coordinated manner. Their cooperation has also gained a lot of attention because the resulting clusters are able to adapt to changes in their environment and to perform complex tasks. However, mimicking such a collective behavior remains a challenge. In the present work, magnesium microparticles are used as chemotactic swimmers with pronounced collective features, allowing the gradual formation of macroscopic agglomerates. The formed clusters act like a single swimmer, able to follow pH gradients. This dynamic behavior can be used to spot in a straightforward way localized corrosion events. The autonomous docking of the swimmers to the corrosion site leads to the formation of a local protection layer, thus increasing corrosion resistance and triggering partial self-healing.
Neurotransmitters are biochemical molecules that transmit a signal from a neuron across the synap... more Neurotransmitters are biochemical molecules that transmit a signal from a neuron across the synapse to a target cell, thus being essential to the function of the central and peripheral nervous system. Dopamine is one of the most important catecholamine neurotransmitters since it is involved in many functions of the human central nervous system, including motor control, reward, or reinforcement. It is of utmost importance to quantify the amount of dopamine since abnormal levels can cause a variety of medical and behavioral problems. For instance, Parkinson’s disease is partially caused by the death of dopamine-secreting neurons. To date, various methods have been developed to measure dopamine levels, and electrochemical biosensing seems to be the most viable due to its robustness, selectivity, sensitivity, and the possibility to achieve real-time measurements. Even if the electrochemical detection is not facile due to the presence of electroactive interfering species with similar red...
Coating of mesoporous silica carriers with dioleoylphosphatidylcholine allowed triggering of the ... more Coating of mesoporous silica carriers with dioleoylphosphatidylcholine allowed triggering of the selective delivery of functional enzymes by lipolysis under simulated intestinal conditions.
According to the US Food and Drug Administration and the European Food Safety Authority, amorphou... more According to the US Food and Drug Administration and the European Food Safety Authority, amorphous forms of silica and silicates are generally recognized to be safe as oral delivery ingredients in amounts up to 1500mg per day. Silica is used in the formulation of solid dosage forms, e.g. tablets, as glidant or lubricant. The synthesis of silica-based materials depends on the payload nature, drug, macromolecule or cell, and on the target release (active or passive). In the literature, most of the examples deal with the encapsulation of drugs in mesoporous silica nanoparticles. Still to date limited reports concerning the delivery of encapsulated macromolecules and cells have been reported in the field of oral delivery, despite the multiple promising examples demonstrating the compatibility of the sol-gel route with biological entities, likewise the interest of silica as an oral carrier. Silica diatoms appear as an elegant, cost-effective and promising alternative to synthetic sol-gel-based materials. This review reports the latest advances silica-based systems and discusses the potential benefits and drawbacks of using silica for oral delivery of drugs, macromolecules or cells.
Langmuir : the ACS journal of surfaces and colloids, Apr 16, 2017
β-galactosidase (β-Gal) is one of the most important enzymes used in milk processing for improvin... more β-galactosidase (β-Gal) is one of the most important enzymes used in milk processing for improving their nutritional quality and digestibility. Herein, β-Gal has been entrapped into a meso-macroporous material (average pore size 9 and 200 nm, respectively) prepared by a sol-gel method from a silica precursor and a dispersion of solid lipid nanoparticles in a micelle phase. The physisorption of the enzyme depends on the concentration of the feed solution and on the pore size of the support. The enzyme is preferentially adsorbed either in mesopores or in macropores, depending on its initial concentration. Moreover, this selective adsorption, arising from the oligomeric complexation of the enzyme (monomer/dimer/tetramer), has an effect on the catalytic activity of the material. Indeed, the enzyme encapsulated in macropores is more active than the enzyme immobilized in mesopores. Designed materials containing β-Gal are of particular interest for food applications and potentially extende...
ABSTRACT Nanorods with motion enhanced through biocatalytically induced self-electrophoresis are ... more ABSTRACT Nanorods with motion enhanced through biocatalytically induced self-electrophoresis are described. To obtain such nanorods, the polymer half of polypyrrole–gold (PPy-Au) nanorods is decorated with horseradish peroxidase (HRP) and their metal half with cytochrome c (Cyt c). If such nanorods are suspended in enzymatically generated mixtures of O2⋅− and H2O2, the immobilized Cyt c is reduced by O2⋅−, and the immobilized HRP is oxidized by H2O2. As both hemeproteins are capable of direct electron transfer to/from solid substrates, the oxidized HRP is subsequently reduced with electrons received, through the nanorod, from the reduced Cyt c. The combined processes cause species from the electrical double layer of the nanorods to move from one end of the nanorod to the other, which powers the motion of the nanorods in the opposite direction. The diffusive motion of the hemeprotein-modified nanorods is characterized by a diffusion coefficient 30 % larger in the presence of O2⋅− and H2O2 than in their absence. Unmodified nanorods do not show such behavior.
Conductive polymers have attracted wide attention since their discovery due to their unique prope... more Conductive polymers have attracted wide attention since their discovery due to their unique properties such as good electrical conductivity, thermal and chemical stability, and low cost. With different possibilities of preparation and deposition on surfaces, they present unique and tunable structures. Because of the ease of incorporating different elements to form composite materials, conductive polymers have been widely used in a plethora of applications. Their inherent mechanical tolerance limit makes them ideal for flexible devices, such as electrodes for batteries, artificial muscles, organic electronics, and sensors. As the demand for the next generation of (wearable) personal and flexible sensing devices is increasing, this review aims to discuss and summarize the recent manufacturing advances made on flexible electrochemical sensors
Miniaturized autonomous swimmers have become more and more important in many areas of research du... more Miniaturized autonomous swimmers have become more and more important in many areas of research due to various fields of use, ranging from biomedical to environmental tasks. Precise and predictable control of their trajectories is a key ingredient for increasing their application potential. This can be typically achieved by using external forces such as magnetic or electric fields. An interesting alternative is to use intrinsic features of the swimmers, which allow them to exhibit chemotaxis. Such a built‐in “intelligence” enables more complex trajectories, relying on mechanisms that can be considered very basic analogs of decision‐making processes. Herein, autonomous light‐emitting chemoelectronic swimmers are presented that are able to navigate along trajectories with increasing complexity. Their decision‐making capacities are characterized by recording the light emitted along their path by a fully integrated light‐emitting diode. Chemotaxis is found to be the main driving force be...
Numerous artificial micro- and nanomotors, as well as various swimmers have been inspired by livi... more Numerous artificial micro- and nanomotors, as well as various swimmers have been inspired by living organisms that are able to move in a coordinated manner. Their cooperation has also gained a lot of attention because the resulting clusters are able to adapt to changes in their environment and to perform complex tasks. However, mimicking such a collective behavior remains a challenge. In the present work, magnesium microparticles are used as chemotactic swimmers with pronounced collective features, allowing the gradual formation of macroscopic agglomerates. The formed clusters act like a single swimmer, able to follow pH gradients. This dynamic behavior can be used to spot in a straightforward way localized corrosion events. The autonomous docking of the swimmers to the corrosion site leads to the formation of a local protection layer, thus increasing corrosion resistance and triggering partial self-healing.
Neurotransmitters are biochemical molecules that transmit a signal from a neuron across the synap... more Neurotransmitters are biochemical molecules that transmit a signal from a neuron across the synapse to a target cell, thus being essential to the function of the central and peripheral nervous system. Dopamine is one of the most important catecholamine neurotransmitters since it is involved in many functions of the human central nervous system, including motor control, reward, or reinforcement. It is of utmost importance to quantify the amount of dopamine since abnormal levels can cause a variety of medical and behavioral problems. For instance, Parkinson’s disease is partially caused by the death of dopamine-secreting neurons. To date, various methods have been developed to measure dopamine levels, and electrochemical biosensing seems to be the most viable due to its robustness, selectivity, sensitivity, and the possibility to achieve real-time measurements. Even if the electrochemical detection is not facile due to the presence of electroactive interfering species with similar red...
Coating of mesoporous silica carriers with dioleoylphosphatidylcholine allowed triggering of the ... more Coating of mesoporous silica carriers with dioleoylphosphatidylcholine allowed triggering of the selective delivery of functional enzymes by lipolysis under simulated intestinal conditions.
According to the US Food and Drug Administration and the European Food Safety Authority, amorphou... more According to the US Food and Drug Administration and the European Food Safety Authority, amorphous forms of silica and silicates are generally recognized to be safe as oral delivery ingredients in amounts up to 1500mg per day. Silica is used in the formulation of solid dosage forms, e.g. tablets, as glidant or lubricant. The synthesis of silica-based materials depends on the payload nature, drug, macromolecule or cell, and on the target release (active or passive). In the literature, most of the examples deal with the encapsulation of drugs in mesoporous silica nanoparticles. Still to date limited reports concerning the delivery of encapsulated macromolecules and cells have been reported in the field of oral delivery, despite the multiple promising examples demonstrating the compatibility of the sol-gel route with biological entities, likewise the interest of silica as an oral carrier. Silica diatoms appear as an elegant, cost-effective and promising alternative to synthetic sol-gel-based materials. This review reports the latest advances silica-based systems and discusses the potential benefits and drawbacks of using silica for oral delivery of drugs, macromolecules or cells.
Langmuir : the ACS journal of surfaces and colloids, Apr 16, 2017
β-galactosidase (β-Gal) is one of the most important enzymes used in milk processing for improvin... more β-galactosidase (β-Gal) is one of the most important enzymes used in milk processing for improving their nutritional quality and digestibility. Herein, β-Gal has been entrapped into a meso-macroporous material (average pore size 9 and 200 nm, respectively) prepared by a sol-gel method from a silica precursor and a dispersion of solid lipid nanoparticles in a micelle phase. The physisorption of the enzyme depends on the concentration of the feed solution and on the pore size of the support. The enzyme is preferentially adsorbed either in mesopores or in macropores, depending on its initial concentration. Moreover, this selective adsorption, arising from the oligomeric complexation of the enzyme (monomer/dimer/tetramer), has an effect on the catalytic activity of the material. Indeed, the enzyme encapsulated in macropores is more active than the enzyme immobilized in mesopores. Designed materials containing β-Gal are of particular interest for food applications and potentially extende...
ABSTRACT Nanorods with motion enhanced through biocatalytically induced self-electrophoresis are ... more ABSTRACT Nanorods with motion enhanced through biocatalytically induced self-electrophoresis are described. To obtain such nanorods, the polymer half of polypyrrole–gold (PPy-Au) nanorods is decorated with horseradish peroxidase (HRP) and their metal half with cytochrome c (Cyt c). If such nanorods are suspended in enzymatically generated mixtures of O2⋅− and H2O2, the immobilized Cyt c is reduced by O2⋅−, and the immobilized HRP is oxidized by H2O2. As both hemeproteins are capable of direct electron transfer to/from solid substrates, the oxidized HRP is subsequently reduced with electrons received, through the nanorod, from the reduced Cyt c. The combined processes cause species from the electrical double layer of the nanorods to move from one end of the nanorod to the other, which powers the motion of the nanorods in the opposite direction. The diffusive motion of the hemeprotein-modified nanorods is characterized by a diffusion coefficient 30 % larger in the presence of O2⋅− and H2O2 than in their absence. Unmodified nanorods do not show such behavior.
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