Session: ABC: Bioanalytics I - Nanomaterials in BioAnalysis

Session Chair: Prof. Dr. Antje Bäumner
English

Engineered nanofiber hybrids as multifunctional 3D-interfaces for electrobioanalytical applications

Nongnoot Wongkaew, University of Regensburg
Engineering of sensing interfaces with (bio)functional nanomaterials have nowadays drawn intense attention in developing novel electrochemical biosensors and enhancing their analytical performance with respect to sensitivity, selectivity, stability and simplicity. Electroactive electrospun nanofibers feature high surface area, introducible (bio)functionalities, and high porosity of a built-in 3D network, making them an excellent candidate as electrochemical transducers in bioanalytical systems. [1] A diverse range of (bio)functionalities can be introduced into the nanofibers either via ex situ or in situ modifications. Investigations on the interconnected relationships between the fabrication process and the resulting electroanalytical performance are crucial in attaining desirable outcomes as will be shown here in two examples. We recently demonstrated the creation of electrospun polyaniline (PANI) nanofibers bearing inherent multi-functionalities for bioanalytical applications via post-doping strategy. [2] We show that a simple doping of electrospun non-conductive PANI nanofibers with acid solutions not only was able to tackle challenges associated with the electrospinnability of highly conductive solutions, but also offered novel (bio)functionalities towards highly selective dopamine detection and polydopamine formation for electrocatalytic hydrazine sensing. Of special interest is also the impact of the post-doping process on the electroanalytical performance. Carbon nanofibers (CNFs) carrying electronanocatalysts are currently developed for non-enzymatic electrochemical sensing. We have previously proposed a one-step laser carbonization of electrospun polyimide (PI) nanofibers containing iron to create laser-induced CNFs (LCNFs) electrodes. [3] The LCNF electrodes not only exhibited fast electron transfer kinetics but also possessed electrocatalytic property towards oxidation of hydrazine due to embedded iron nanocatalysts. This opens up a range of interesting possibilities for an in situ generation of LCNF electrode-doped electronanocatalysts. Ultimately, we are also working toward integrating these electroactive (bio)functional nanofibers into miniaturized analytical systems as they have a great potential to lead to high performing point-of-need devices applicable in diverse areas, including clinical diagnostics, food safety, environmental monitoring, and biodefense.
English

Engineered nanofiber hybrids as multifunctional 3D-interfaces for electrobioanalytical applications

Nongnoot Wongkaew, University of Regensburg
Engineering of sensing interfaces with (bio)functional nanomaterials have nowadays drawn intense attention in developing novel electrochemical biosensors and enhancing their analytical performance with respect to sensitivity, selectivity, stability and simplicity. Electroactive electrospun nanofibers feature high surface area, introducible (bio)functionalities, and high porosity of a built-in 3D network, making them an excellent candidate as electrochemical transducers in bioanalytical systems. [1] A diverse range of (bio)functionalities can be introduced into the nanofibers either via ex situ or in situ modifications. Investigations on the interconnected relationships between the fabrication process and the resulting electroanalytical performance are crucial in attaining desirable outcomes as will be shown here in two examples. We recently demonstrated the creation of electrospun polyaniline (PANI) nanofibers bearing inherent multi-functionalities for bioanalytical applications via post-doping strategy. [2] We show that a simple doping of electrospun non-conductive PANI nanofibers with acid solutions not only was able to tackle challenges associated with the electrospinnability of highly conductive solutions, but also offered novel (bio)functionalities towards highly selective dopamine detection and polydopamine formation for electrocatalytic hydrazine sensing. Of special interest is also the impact of the post-doping process on the electroanalytical performance. Carbon nanofibers (CNFs) carrying electronanocatalysts are currently developed for non-enzymatic electrochemical sensing. We have previously proposed a one-step laser carbonization of electrospun polyimide (PI) nanofibers containing iron to create laser-induced CNFs (LCNFs) electrodes. [3] The LCNF electrodes not only exhibited fast electron transfer kinetics but also possessed electrocatalytic property towards oxidation of hydrazine due to embedded iron nanocatalysts. This opens up a range of interesting possibilities for an in situ generation of LCNF electrode-doped electronanocatalysts. Ultimately, we are also working toward integrating these electroactive (bio)functional nanofibers into miniaturized analytical systems as they have a great potential to lead to high performing point-of-need devices applicable in diverse areas, including clinical diagnostics, food safety, environmental monitoring, and biodefense.
English

Engineered nanofiber hybrids as multifunctional 3D-interfaces for electrobioanalytical applications

Nongnoot Wongkaew, University of Regensburg
Engineering of sensing interfaces with (bio)functional nanomaterials have nowadays drawn intense attention in developing novel electrochemical biosensors and enhancing their analytical performance with respect to sensitivity, selectivity, stability and simplicity. Electroactive electrospun nanofibers feature high surface area, introducible (bio)functionalities, and high porosity of a built-in 3D network, making them an excellent candidate as electrochemical transducers in bioanalytical systems. [1] A diverse range of (bio)functionalities can be introduced into the nanofibers either via ex situ or in situ modifications. Investigations on the interconnected relationships between the fabrication process and the resulting electroanalytical performance are crucial in attaining desirable outcomes as will be shown here in two examples. We recently demonstrated the creation of electrospun polyaniline (PANI) nanofibers bearing inherent multi-functionalities for bioanalytical applications via post-doping strategy. [2] We show that a simple doping of electrospun non-conductive PANI nanofibers with acid solutions not only was able to tackle challenges associated with the electrospinnability of highly conductive solutions, but also offered novel (bio)functionalities towards highly selective dopamine detection and polydopamine formation for electrocatalytic hydrazine sensing. Of special interest is also the impact of the post-doping process on the electroanalytical performance. Carbon nanofibers (CNFs) carrying electronanocatalysts are currently developed for non-enzymatic electrochemical sensing. We have previously proposed a one-step laser carbonization of electrospun polyimide (PI) nanofibers containing iron to create laser-induced CNFs (LCNFs) electrodes. [3] The LCNF electrodes not only exhibited fast electron transfer kinetics but also possessed electrocatalytic property towards oxidation of hydrazine due to embedded iron nanocatalysts. This opens up a range of interesting possibilities for an in situ generation of LCNF electrode-doped electronanocatalysts. Ultimately, we are also working toward integrating these electroactive (bio)functional nanofibers into miniaturized analytical systems as they have a great potential to lead to high performing point-of-need devices applicable in diverse areas, including clinical diagnostics, food safety, environmental monitoring, and biodefense.
English

Janus emulsions as transducers in liquid biosensing platforms

Lukas Zeininger, MPI of Colloids & Interfaces
Dynamic multiphase complex emulsions formed from two or more immiscible solvents represent a unique platform for the generation of new triggerable materials. In designing our methods, we make use of solvent combinations that are immiscible at room temperature but exhibit a lower (LCST) or upper critical solution temperature (UCST). Emulsification of the mixture below LCST or above UCST enables a simple one-step fabrication of complex multicomponent emulsions as well as structured soft-matter particles with highly uniform morphology via temperature-induced phase separation. The morphology of these dynamic liquid colloids is exclusively controlled by a balance of interfacial tensions. As a result, the droplet geometries can be controllably altered after emulsification. Dynamic liquid colloids can selectively invert morphology in response to external stimuli including the presence of specific analytes, small pH changes, light or high energy irradiation, and the presence of an electric or magnetic field and thus provide a new active element for novel and existing emulsion technologies including chemotaxis, the fabrication of optical metamaterials, and chemical/biological sensing. Here, I will present our latest efforts in fabricating biocompatible aqueous-based responsive Janus and Cerberus emulsion droplets. These complex aqueous emulsion droplets represent a promising platform for the encapsulation of cells, pharmaceuticals, or nutrients, as well as for mimicking the compartmentalization of biomolecules found in living cells. Our approach that is based on a temperature-induced phase separation inside as-formed emulsion droplets comprising mixtures of two or more hydrophilic polymers, enables us to fine-tune and dynamically alter the droplet morphology as a function of the types and molecular weights of the polymers as well as the surfactant effectiveness. The associated ability to rationally design aqueous Janus emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new dynamic soft materials for a variety of applications beyond encapsulation, including to optically monitor variations of interfacial tensions, e.g. for the development of chemical and biological sensors. In this context, I will show how an associated understanding of the unique chemical-morphologicaloptical coupling inside chemically functionalized active Janus emulsions creates a solid foundation for the development of sensing paradigms targeting a series of biological analytes, including a rapid and sensitive method for the detection of common foodborne pathogens Escherichia Coli and Salmonella enterica bacteria.
English

Janus emulsions as transducers in liquid biosensing platforms

Lukas Zeininger, MPI of Colloids & Interfaces
Dynamic multiphase complex emulsions formed from two or more immiscible solvents represent a unique platform for the generation of new triggerable materials. In designing our methods, we make use of solvent combinations that are immiscible at room temperature but exhibit a lower (LCST) or upper critical solution temperature (UCST). Emulsification of the mixture below LCST or above UCST enables a simple one-step fabrication of complex multicomponent emulsions as well as structured soft-matter particles with highly uniform morphology via temperature-induced phase separation. The morphology of these dynamic liquid colloids is exclusively controlled by a balance of interfacial tensions. As a result, the droplet geometries can be controllably altered after emulsification. Dynamic liquid colloids can selectively invert morphology in response to external stimuli including the presence of specific analytes, small pH changes, light or high energy irradiation, and the presence of an electric or magnetic field and thus provide a new active element for novel and existing emulsion technologies including chemotaxis, the fabrication of optical metamaterials, and chemical/biological sensing. Here, I will present our latest efforts in fabricating biocompatible aqueous-based responsive Janus and Cerberus emulsion droplets. These complex aqueous emulsion droplets represent a promising platform for the encapsulation of cells, pharmaceuticals, or nutrients, as well as for mimicking the compartmentalization of biomolecules found in living cells. Our approach that is based on a temperature-induced phase separation inside as-formed emulsion droplets comprising mixtures of two or more hydrophilic polymers, enables us to fine-tune and dynamically alter the droplet morphology as a function of the types and molecular weights of the polymers as well as the surfactant effectiveness. The associated ability to rationally design aqueous Janus emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new dynamic soft materials for a variety of applications beyond encapsulation, including to optically monitor variations of interfacial tensions, e.g. for the development of chemical and biological sensors. In this context, I will show how an associated understanding of the unique chemical-morphologicaloptical coupling inside chemically functionalized active Janus emulsions creates a solid foundation for the development of sensing paradigms targeting a series of biological analytes, including a rapid and sensitive method for the detection of common foodborne pathogens Escherichia Coli and Salmonella enterica bacteria.
English

Janus emulsions as transducers in liquid biosensing platforms

Lukas Zeininger, MPI of Colloids & Interfaces
Dynamic multiphase complex emulsions formed from two or more immiscible solvents represent a unique platform for the generation of new triggerable materials. In designing our methods, we make use of solvent combinations that are immiscible at room temperature but exhibit a lower (LCST) or upper critical solution temperature (UCST). Emulsification of the mixture below LCST or above UCST enables a simple one-step fabrication of complex multicomponent emulsions as well as structured soft-matter particles with highly uniform morphology via temperature-induced phase separation. The morphology of these dynamic liquid colloids is exclusively controlled by a balance of interfacial tensions. As a result, the droplet geometries can be controllably altered after emulsification. Dynamic liquid colloids can selectively invert morphology in response to external stimuli including the presence of specific analytes, small pH changes, light or high energy irradiation, and the presence of an electric or magnetic field and thus provide a new active element for novel and existing emulsion technologies including chemotaxis, the fabrication of optical metamaterials, and chemical/biological sensing. Here, I will present our latest efforts in fabricating biocompatible aqueous-based responsive Janus and Cerberus emulsion droplets. These complex aqueous emulsion droplets represent a promising platform for the encapsulation of cells, pharmaceuticals, or nutrients, as well as for mimicking the compartmentalization of biomolecules found in living cells. Our approach that is based on a temperature-induced phase separation inside as-formed emulsion droplets comprising mixtures of two or more hydrophilic polymers, enables us to fine-tune and dynamically alter the droplet morphology as a function of the types and molecular weights of the polymers as well as the surfactant effectiveness. The associated ability to rationally design aqueous Janus emulsion droplets with previously unattainable dynamic control over their morphologies after emulsification entails the potential to design new dynamic soft materials for a variety of applications beyond encapsulation, including to optically monitor variations of interfacial tensions, e.g. for the development of chemical and biological sensors. In this context, I will show how an associated understanding of the unique chemical-morphologicaloptical coupling inside chemically functionalized active Janus emulsions creates a solid foundation for the development of sensing paradigms targeting a series of biological analytes, including a rapid and sensitive method for the detection of common foodborne pathogens Escherichia Coli and Salmonella enterica bacteria.
English

Innovative plasmonic nanostructures for vibrational biosensing

Dana Cialla-May, Leibniz Institute of Photonic Technology
To allow for a sensitive detection of target molecules and substances, the development and application of powerful plasmonic nanostructures is pursued. [1] Due to the interaction with light, strong electromagnetic fields are generated enhancing, for example, the Raman fingerprint spectrum of an analyte of interest in close vicinity by 6 to 8 orders of magnitude. [2] This technique, so-called surface enhanced Raman spectroscopy (SERS), is today an attractive tool in bioanalytics and biosensing. [3] As SERS-active sensor surfaces, mainly silver and gold nanostructures are employed fabricated by bottom-up and top-down strategies as well as self-assembled arrangement and template-assisted approaches. [1] As SERS-based detection schemes, three main approaches are available: i.e. label-free or direct SERS, SERS labels or tags as well as molecular sensors. Within this contribution we introduce application examples using SERS addressing the three main detection schemes: (i) In order to identify infections with Pseudomonas aeruginosa, the specific metabolite pyocyanin was successfully detected via label-free SERS within the medical relevant range. [4] The potential for real application scenarios was furthermore demonstrated by investigating the metabolite in the matrix of artificial sputum combined with a simplified sample preparation protocol. [5] (ii) SERS labels were modified with mannose to allow for a specific uptake by macrophages which are accumulated in atherosclerotic plaques. [6] Thus, an SERS-based in-vitro model for the detection of vulnerable atherosclerotic plaques was demonstrated. (iii) As SERS-based molecular sensors, plasmonic nanoparticles were modified with dipicolylamine-based ligand molecules being specific for the interaction with copper(II) ions. [7] The detection was demonstrated in white wine for concentrations lower than the maximum recommended concentration. Acknowledgement: We gratefully acknowledge the Federal Ministry of Education and Research, Germany (BMBF) for supporting the InfectoGnostics (13GW0096F) and EXASENS (13N13856) project grants as well as BMBF and German Aerospace Center (DLR) for supporting the Myco-NET2 (01DN15028) project grant.
English

Innovative plasmonic nanostructures for vibrational biosensing

Dana Cialla-May, Leibniz Institute of Photonic Technology
To allow for a sensitive detection of target molecules and substances, the development and application of powerful plasmonic nanostructures is pursued. [1] Due to the interaction with light, strong electromagnetic fields are generated enhancing, for example, the Raman fingerprint spectrum of an analyte of interest in close vicinity by 6 to 8 orders of magnitude. [2] This technique, so-called surface enhanced Raman spectroscopy (SERS), is today an attractive tool in bioanalytics and biosensing. [3] As SERS-active sensor surfaces, mainly silver and gold nanostructures are employed fabricated by bottom-up and top-down strategies as well as self-assembled arrangement and template-assisted approaches. [1] As SERS-based detection schemes, three main approaches are available: i.e. label-free or direct SERS, SERS labels or tags as well as molecular sensors. Within this contribution we introduce application examples using SERS addressing the three main detection schemes: (i) In order to identify infections with Pseudomonas aeruginosa, the specific metabolite pyocyanin was successfully detected via label-free SERS within the medical relevant range. [4] The potential for real application scenarios was furthermore demonstrated by investigating the metabolite in the matrix of artificial sputum combined with a simplified sample preparation protocol. [5] (ii) SERS labels were modified with mannose to allow for a specific uptake by macrophages which are accumulated in atherosclerotic plaques. [6] Thus, an SERS-based in-vitro model for the detection of vulnerable atherosclerotic plaques was demonstrated. (iii) As SERS-based molecular sensors, plasmonic nanoparticles were modified with dipicolylamine-based ligand molecules being specific for the interaction with copper(II) ions. [7] The detection was demonstrated in white wine for concentrations lower than the maximum recommended concentration. Acknowledgement: We gratefully acknowledge the Federal Ministry of Education and Research, Germany (BMBF) for supporting the InfectoGnostics (13GW0096F) and EXASENS (13N13856) project grants as well as BMBF and German Aerospace Center (DLR) for supporting the Myco-NET2 (01DN15028) project grant.
English

Innovative plasmonic nanostructures for vibrational biosensing

Dana Cialla-May, Leibniz Institute of Photonic Technology
To allow for a sensitive detection of target molecules and substances, the development and application of powerful plasmonic nanostructures is pursued. [1] Due to the interaction with light, strong electromagnetic fields are generated enhancing, for example, the Raman fingerprint spectrum of an analyte of interest in close vicinity by 6 to 8 orders of magnitude. [2] This technique, so-called surface enhanced Raman spectroscopy (SERS), is today an attractive tool in bioanalytics and biosensing. [3] As SERS-active sensor surfaces, mainly silver and gold nanostructures are employed fabricated by bottom-up and top-down strategies as well as self-assembled arrangement and template-assisted approaches. [1] As SERS-based detection schemes, three main approaches are available: i.e. label-free or direct SERS, SERS labels or tags as well as molecular sensors. Within this contribution we introduce application examples using SERS addressing the three main detection schemes: (i) In order to identify infections with Pseudomonas aeruginosa, the specific metabolite pyocyanin was successfully detected via label-free SERS within the medical relevant range. [4] The potential for real application scenarios was furthermore demonstrated by investigating the metabolite in the matrix of artificial sputum combined with a simplified sample preparation protocol. [5] (ii) SERS labels were modified with mannose to allow for a specific uptake by macrophages which are accumulated in atherosclerotic plaques. [6] Thus, an SERS-based in-vitro model for the detection of vulnerable atherosclerotic plaques was demonstrated. (iii) As SERS-based molecular sensors, plasmonic nanoparticles were modified with dipicolylamine-based ligand molecules being specific for the interaction with copper(II) ions. [7] The detection was demonstrated in white wine for concentrations lower than the maximum recommended concentration. Acknowledgement: We gratefully acknowledge the Federal Ministry of Education and Research, Germany (BMBF) for supporting the InfectoGnostics (13GW0096F) and EXASENS (13N13856) project grants as well as BMBF and German Aerospace Center (DLR) for supporting the Myco-NET2 (01DN15028) project grant.
English

Carbon based nanostructures: an electoanalytical and biomedical perspective

Sabine Szunerits, University of Lille
Clinical analysis benefits world-wide from a variety of diagnostic tests. These analytical tests should be fast and highly accurate to help in establishing a treatment protocol that is appropriate for the patient. The interest in the development of new clinical tests is not only driven by the demand to sense new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today, electrochemical and field-effect based biosensors are prominent players. For such advanced biosensors, the choice of the electrical transducer, the recognition element and the surface linking strategy, have to be considered simultaneously, making the construction of viable biosensing platforms of at great challenge. The attractive properties of carbon- based nanomaterials have paved the way for the fabrication of a wide range of electrical and electrochemical based biosensors with improved analytical performance. This talk will provide insights into the various benefits of carbon nanomaterials based bioelectrical and bioelectrochemical sensors. In parallel, some nanomedical aspects of carbon-based nanomaterials ultimately correlated with the development of biosensors will be discussed.
English

Carbon based nanostructures: an electoanalytical and biomedical perspective

Sabine Szunerits, University of Lille
Clinical analysis benefits world-wide from a variety of diagnostic tests. These analytical tests should be fast and highly accurate to help in establishing a treatment protocol that is appropriate for the patient. The interest in the development of new clinical tests is not only driven by the demand to sense new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today, electrochemical and field-effect based biosensors are prominent players. For such advanced biosensors, the choice of the electrical transducer, the recognition element and the surface linking strategy, have to be considered simultaneously, making the construction of viable biosensing platforms of at great challenge. The attractive properties of carbon- based nanomaterials have paved the way for the fabrication of a wide range of electrical and electrochemical based biosensors with improved analytical performance. This talk will provide insights into the various benefits of carbon nanomaterials based bioelectrical and bioelectrochemical sensors. In parallel, some nanomedical aspects of carbon-based nanomaterials ultimately correlated with the development of biosensors will be discussed.
English

Carbon based nanostructures: an electoanalytical and biomedical perspective

Sabine Szunerits, University of Lille
Clinical analysis benefits world-wide from a variety of diagnostic tests. These analytical tests should be fast and highly accurate to help in establishing a treatment protocol that is appropriate for the patient. The interest in the development of new clinical tests is not only driven by the demand to sense new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today, electrochemical and field-effect based biosensors are prominent players. For such advanced biosensors, the choice of the electrical transducer, the recognition element and the surface linking strategy, have to be considered simultaneously, making the construction of viable biosensing platforms of at great challenge. The attractive properties of carbon- based nanomaterials have paved the way for the fabrication of a wide range of electrical and electrochemical based biosensors with improved analytical performance. This talk will provide insights into the various benefits of carbon nanomaterials based bioelectrical and bioelectrochemical sensors. In parallel, some nanomedical aspects of carbon-based nanomaterials ultimately correlated with the development of biosensors will be discussed.