... Sergio E. Hernández, Vicente D. Rodríguez, Justo Pérez, Felipe A. Martín, Miguel A. Castellan... more ... Sergio E. Hernández, Vicente D. Rodríguez, Justo Pérez, Felipe A. Martín, Miguel A. Castellano, Jose Luis Gonzalez-Mora. ... SAPrahl, M.Keijzer, SLJacques, and AJWelch, A Monte Carlo model of light propagation in tissue, in Dosimetry of Laser Radiation in Medicine and ...
The successful application of biosensors for in-vivo monitoring of complex media, such as biologi... more The successful application of biosensors for in-vivo monitoring of complex media, such as biological tissues and fluids, demands that strict criteria be addressed in the device design phase. In the context of monitoring brain neurotransmitters in vivo, factors that impact on implantable amperometric biosensor performance include biocompatibility, minimization of tissue disruption, target analyte sensitivity, tolerance to fluctuations in oxygen levels, selectivity against common endogenous reducing agents, and long-term functional stability. This article reviews, with sample citations, the main issues involved in the design and application of amperometric biosensors for in-vivo monitoring of key neurochemical molecules, including dopamine, glutamate, acetylcholine, serine, and hydrogen peroxide.
Biosensors are analytical devices that utilize biological interactions to detect and quantify cli... more Biosensors are analytical devices that utilize biological interactions to detect and quantify clinical biomarkers, contaminants, allergens, and microorganisms. They combine different disciplines including analytical chemistry, molecular biology, and electrical engineering. Biosensors operate by coupling a bioreceptor, such as nucleic acid or proteins, with a transducer that converts the biological interaction into an electrical signal. Electrochemical and optical transduction are commonly used approaches due to their high detection capability and compatibility with miniaturization. Biosensors provide both high specificity and sensitivity and can be integrated into low-cost microfluidic platforms for rapid and point-of-care applications. These attributes make these devices valuable tools in analytical chemistry, particularly for early diagnostic applications. However, conventional biosensors face challenges related to the immobilization of biorecognition elements on the transducer su...
As brain functional resonance magnetic studies show an aberrant trajectory of neurodevelopment, i... more As brain functional resonance magnetic studies show an aberrant trajectory of neurodevelopment, it is reasonable to predict that the degree of neurochemical abnormalities indexed by magnetic resonance spectroscopy (1H-MRS) might also change according to the developmental stages and brain regions in autism spectrum disorders (ASDs). Since specific N-Acetyl-aspartate (NAA) changes in children’s metabolism have been found in the anterior cingulate cortex (ACC) but not in the posterior cingulate cortex (PCC), we analyzed whether the metabolites of ASD youths change between the cingulate cortices using 1H-MRS. l-glutamate (Glu) and l-Acetyl-aspartate (NAA) are products from the N-Acetyl-aspartyl-glutamate (NAAG) metabolism in a reaction that requires the participation of neurons, oligodendrocytes, and astrocytes. This altered tri-cellular metabolism has been described in several neurological diseases, but not in ASD. Compared to the typical development (TD) group, the ASD group had an ab...
The present work describes the use of noninvasive diffuse optical tomography (DOT) technology to ... more The present work describes the use of noninvasive diffuse optical tomography (DOT) technology to measure hemodynamic changes, providing relevant information which helps to understand the basis of neurophysiology in the human brain. Advantages such as portability, direct measurements of hemoglobin state, temporal resolution, non‐restricted movements as occurs in magnetic resonance imaging (MRI) devices mean that DOT technology can be used in research and clinical fields. In this review we covered the neurophysiology, physical principles underlying optical imaging during tissue‐light interactions, and technology commonly used during the construction of a DOT device including the source‐detector requirements to improve the image quality. DOT provides 3D cerebral activation images due to complex mathematical models which describe the light propagation inside the tissue head. Moreover, we describe briefly the use of Bayesian methods for raw DOT data filtering as an alternative to linear ...
The present work describes noninvasive diffuse optical tomography (DOT), a technology for measuri... more The present work describes noninvasive diffuse optical tomography (DOT), a technology for measuring hemodynamic changes in the brain. These changes provide relevant information that helps us to understand the basis of neurophysiology in the human brain. Advantages, such as portability, direct measurements of hemoglobin state, temporal resolution, and the lack of need to restrict movements, as is necessary in magnetic resonance imaging (MRI) devices, means that DOT technology can be used both in research and clinically. Here, we describe the use of Bayesian methods to filter raw DOT data as an alternative to the linear filters widely used in signal processing. Common problems, such as filter selection or a false interpretation of the results, which is sometimes caused by the interference of background physiological noise with neural activity, can be avoided with this new method.
ABSTRACT First-generation amperometric glucose biosensors are the most commonly used method for g... more ABSTRACT First-generation amperometric glucose biosensors are the most commonly used method for glucose monitoring in neuroscience. Nevertheless, biosensors of this genre suffer from the so-called “oxygen deficit”. This problem is particularly acute when the oxygen concentration is low, as is the case in brain extracellular fluid. In the present work we use different fluorocarbons, such as Nafion and H700, to mitigate the oxygen deficit. These fluorocarbon-derived materials display a remarkable solubility for oxygen, and are able to act as oxygen reservoirs supporting the enzymatic reaction. Different biosensor configurations are presented, evaluating their sensitivity, linear range and oxygen dependence. Optimized Nafion- and H700-modified biosensors displayed a remarkable oxygen tolerance, with KM(O2) values as low as 11 and 4 μ mol L−1, respectively, and an appropriate sensitivity for in-vivo applications. Finally, in-vivo data are reported in order to illustrate the application of such devices in neuroscience applications.
The synthesis of poly(dopamine)-modified magnetic nanoparticles and their biosensing application ... more The synthesis of poly(dopamine)-modified magnetic nanoparticles and their biosensing application to detect phenolic compounds is reported in this work.
... Sergio E. Hernández, Vicente D. Rodríguez, Justo Pérez, Felipe A. Martín, Miguel A. Castellan... more ... Sergio E. Hernández, Vicente D. Rodríguez, Justo Pérez, Felipe A. Martín, Miguel A. Castellano, Jose Luis Gonzalez-Mora. ... SAPrahl, M.Keijzer, SLJacques, and AJWelch, A Monte Carlo model of light propagation in tissue, in Dosimetry of Laser Radiation in Medicine and ...
The successful application of biosensors for in-vivo monitoring of complex media, such as biologi... more The successful application of biosensors for in-vivo monitoring of complex media, such as biological tissues and fluids, demands that strict criteria be addressed in the device design phase. In the context of monitoring brain neurotransmitters in vivo, factors that impact on implantable amperometric biosensor performance include biocompatibility, minimization of tissue disruption, target analyte sensitivity, tolerance to fluctuations in oxygen levels, selectivity against common endogenous reducing agents, and long-term functional stability. This article reviews, with sample citations, the main issues involved in the design and application of amperometric biosensors for in-vivo monitoring of key neurochemical molecules, including dopamine, glutamate, acetylcholine, serine, and hydrogen peroxide.
Biosensors are analytical devices that utilize biological interactions to detect and quantify cli... more Biosensors are analytical devices that utilize biological interactions to detect and quantify clinical biomarkers, contaminants, allergens, and microorganisms. They combine different disciplines including analytical chemistry, molecular biology, and electrical engineering. Biosensors operate by coupling a bioreceptor, such as nucleic acid or proteins, with a transducer that converts the biological interaction into an electrical signal. Electrochemical and optical transduction are commonly used approaches due to their high detection capability and compatibility with miniaturization. Biosensors provide both high specificity and sensitivity and can be integrated into low-cost microfluidic platforms for rapid and point-of-care applications. These attributes make these devices valuable tools in analytical chemistry, particularly for early diagnostic applications. However, conventional biosensors face challenges related to the immobilization of biorecognition elements on the transducer su...
As brain functional resonance magnetic studies show an aberrant trajectory of neurodevelopment, i... more As brain functional resonance magnetic studies show an aberrant trajectory of neurodevelopment, it is reasonable to predict that the degree of neurochemical abnormalities indexed by magnetic resonance spectroscopy (1H-MRS) might also change according to the developmental stages and brain regions in autism spectrum disorders (ASDs). Since specific N-Acetyl-aspartate (NAA) changes in children’s metabolism have been found in the anterior cingulate cortex (ACC) but not in the posterior cingulate cortex (PCC), we analyzed whether the metabolites of ASD youths change between the cingulate cortices using 1H-MRS. l-glutamate (Glu) and l-Acetyl-aspartate (NAA) are products from the N-Acetyl-aspartyl-glutamate (NAAG) metabolism in a reaction that requires the participation of neurons, oligodendrocytes, and astrocytes. This altered tri-cellular metabolism has been described in several neurological diseases, but not in ASD. Compared to the typical development (TD) group, the ASD group had an ab...
The present work describes the use of noninvasive diffuse optical tomography (DOT) technology to ... more The present work describes the use of noninvasive diffuse optical tomography (DOT) technology to measure hemodynamic changes, providing relevant information which helps to understand the basis of neurophysiology in the human brain. Advantages such as portability, direct measurements of hemoglobin state, temporal resolution, non‐restricted movements as occurs in magnetic resonance imaging (MRI) devices mean that DOT technology can be used in research and clinical fields. In this review we covered the neurophysiology, physical principles underlying optical imaging during tissue‐light interactions, and technology commonly used during the construction of a DOT device including the source‐detector requirements to improve the image quality. DOT provides 3D cerebral activation images due to complex mathematical models which describe the light propagation inside the tissue head. Moreover, we describe briefly the use of Bayesian methods for raw DOT data filtering as an alternative to linear ...
The present work describes noninvasive diffuse optical tomography (DOT), a technology for measuri... more The present work describes noninvasive diffuse optical tomography (DOT), a technology for measuring hemodynamic changes in the brain. These changes provide relevant information that helps us to understand the basis of neurophysiology in the human brain. Advantages, such as portability, direct measurements of hemoglobin state, temporal resolution, and the lack of need to restrict movements, as is necessary in magnetic resonance imaging (MRI) devices, means that DOT technology can be used both in research and clinically. Here, we describe the use of Bayesian methods to filter raw DOT data as an alternative to the linear filters widely used in signal processing. Common problems, such as filter selection or a false interpretation of the results, which is sometimes caused by the interference of background physiological noise with neural activity, can be avoided with this new method.
ABSTRACT First-generation amperometric glucose biosensors are the most commonly used method for g... more ABSTRACT First-generation amperometric glucose biosensors are the most commonly used method for glucose monitoring in neuroscience. Nevertheless, biosensors of this genre suffer from the so-called “oxygen deficit”. This problem is particularly acute when the oxygen concentration is low, as is the case in brain extracellular fluid. In the present work we use different fluorocarbons, such as Nafion and H700, to mitigate the oxygen deficit. These fluorocarbon-derived materials display a remarkable solubility for oxygen, and are able to act as oxygen reservoirs supporting the enzymatic reaction. Different biosensor configurations are presented, evaluating their sensitivity, linear range and oxygen dependence. Optimized Nafion- and H700-modified biosensors displayed a remarkable oxygen tolerance, with KM(O2) values as low as 11 and 4 μ mol L−1, respectively, and an appropriate sensitivity for in-vivo applications. Finally, in-vivo data are reported in order to illustrate the application of such devices in neuroscience applications.
The synthesis of poly(dopamine)-modified magnetic nanoparticles and their biosensing application ... more The synthesis of poly(dopamine)-modified magnetic nanoparticles and their biosensing application to detect phenolic compounds is reported in this work.
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