@article{BaeckerKochEibenetal.2017, author = {B{\"a}cker, Matthias and Koch, Claudia and Eiben, Sabine and Geiger, Fania and Eber, Fabian and Gliemann, Hartmut and Poghossian, Arshak and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Tobacco mosaic virus as enzyme nanocarrier for electrochemical biosensors}, series = {Sensors and Actuators B: Chemical}, volume = {238}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2016.07.096}, pages = {716 -- 722}, year = {2017}, abstract = {The conjunction of (bio-)chemical recognition elements with nanoscale biological building blocks such as virus particles is considered as a very promising strategy for the creation of biohybrids opening novel opportunities for label-free biosensing. This work presents a new approach for the development of biosensors using tobacco mosaic virus (TMV) nanotubes or coat proteins (CPs) as enzyme nanocarriers. Sensor chips combining an array of Pt electrodes loaded with glucose oxidase (GOD)-modified TMV nanotubes or CP aggregates were used for amperometric detection of glucose as a model system for the first time. The presence of TMV nanotubes or CPs on the sensor surface allows binding of a high amount of precisely positioned enzymes without substantial loss of their activity, and may also ensure accessibility of their active centers for analyte molecules. Specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CPs was achieved via bioaffinity binding. These layouts were tested in parallel with glucose sensors with adsorptively immobilized [SA]-GOD, as well as [SA]-GOD crosslinked with glutardialdehyde, and came out to exhibit superior sensor performance. The achieved results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for future applications in biosensorics and biochips.}, language = {en} } @article{SchusserKrischerBaeckeretal.2015, author = {Schusser, Sebastian and Krischer, Maximillian and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Monitoring of the Enzymatically Catalyzed Degradation of Biodegradable Polymers by Means of Capacitive Field-Effect Sensors}, series = {Analytical Chemistry}, volume = {87}, journal = {Analytical Chemistry}, number = {13}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-6882}, doi = {10.1021/acs.analchem.5b00617}, pages = {6607 -- 6613}, year = {2015}, abstract = {Designing novel or optimizing existing biodegradable polymers for biomedical applications requires numerous tests on the effect of substances on the degradation process. In the present work, polymer-modified electrolyte-insulator-semiconductor (PMEIS) sensors have been applied for monitoring an enzymatically catalyzed degradation of polymers for the first time. The thin films of biodegradable polymer poly(d,l-lactic acid) and enzyme lipase were used as a model system. During degradation, the sensors were read-out by means of impedance spectroscopy. In order to interpret the data obtained from impedance measurements, an electrical equivalent circuit model was developed. In addition, morphological investigations of the polymer surface have been performed by means of in situ atomic force microscopy. The sensor signal change, which reflects the progress of degradation, indicates an accelerated degradation in the presence of the enzyme compared to hydrolysis in neutral pH buffer media. The degradation rate increases with increasing enzyme concentration. The obtained results demonstrate the potential of PMEIS sensors as a very promising tool for in situ and real-time monitoring of degradation of polymers.}, language = {en} } @article{SchusserKrischerMolinetal.2015, author = {Schusser, Sebastian and Krischer, M. and Molin, D. G. M. and Akker, N. M. S. van den and B{\"a}cker, Matthias and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Sensor System for in-situ and Real-time Monitoring of Polymer (bio) degradation}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.815}, pages = {948 -- 951}, year = {2015}, abstract = {A sensor system for investigating (bio)degradationprocesses of polymers is presented. The system utilizes semiconductor field-effect sensors and is capable of monitoring the degradation process in-situ and in real-time. The degradation of the polymer poly(d,l-lactic acid) is exemplarily monitored in solutions with different pH value, pH-buffer solution containing the model enzyme lipase from Rhizomucormiehei and cell-culture medium containing supernatants from stimulated and non-stimulated THP-1-derived macrophages mimicking activation of the immune system.}, language = {en} } @article{MolinnusBaeckerSiegertetal.2015, author = {Molinnus, Denise and B{\"a}cker, Matthias and Siegert, Petra and Willenberg, H. and Poghossian, Arshak and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Detection of Adrenaline Based on Substrate Recycling Amplification}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.708}, pages = {540 -- 543}, year = {2015}, abstract = {An amperometric enzyme biosensor has been applied for the detection of adrenaline. The adrenaline biosensor has been prepared by modification of an oxygen electrode with the enzyme laccase that operates at a broad pH range between pH 3.5 to pH 8. The enzyme molecules were immobilized via cross-linking with glutaraldehyde. The sensitivity of the developed adrenaline biosensor in different pH buffer solutions has been studied.}, language = {en} } @article{DelleHuckBaeckeretal.2015, author = {Delle, Lotta E. and Huck, Christina and B{\"a}cker, Matthias and M{\"u}ller, Frank and Grandthyll, Samuel and Jacobs, Karin and Lilischkis, Rainer and Vu, Xuan T. and Sch{\"o}ning, Michael Josef and Wagner, Patrick and Thoelen, Roland and Weil, Maryam and Ingebrandt, Sven}, title = {Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431863}, pages = {1327 -- 1334}, year = {2015}, language = {en} } @article{MolinnusBaeckerIkenetal.2015, author = {Molinnus, Denise and B{\"a}cker, Matthias and Iken, Heiko and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Concept for a biomolecular logic chip with an integrated sensor and actuator function}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431913}, pages = {1382 -- 1388}, year = {2015}, abstract = {A concept for a new generation of an integrated multi-functional biosensor/actuator system is developed, which is based on biomolecular logic principles. Such a system is expected to be able to detect multiple biochemical input signals simultaneously and in real-time and convert them into electrical output signals with logical operations such as OR, AND, etc. The system can be designed as a closed-loop drug release device triggered by an enzyme logic gate, while the release of the drug induced by the actuator at the required dosage and timing will be controlled by an additional drug sensor. Thus, the system could help to make an accurate and specific diagnosis. The presented concept is exemplarily demonstrated by using an enzyme logic gate based on a glucose/glucose oxidase system, a temperature-responsive hydrogel mimicking the actuator function and an insulin (drug) sensor. In this work, the results of functional testing of individual amperometric glucose and insulin sensors as well as an impedimetric sensor for the detection of the hydrogel swelling/shrinking are presented.}, language = {en} } @article{HuckPoghossianBaeckeretal.2015, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Reisert, Steffen and Kramer, Friederike and Begoyan, Vardges K. and Buniatyan, Vahe V. and Sch{\"o}ning, Michael Josef}, title = {Multi-parameter sensing using high-k oxide of barium strontium titanate}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431911}, pages = {1259}, year = {2015}, abstract = {High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors. In this work, a Si-based sensor chip containing Pt interdigitated electrodes covered with a thin BST layer (485 nm) has been developed for multi-parameter chemical sensing. The chip has been applied for the contactless measurement of the electrolyte conductivity, the detection of adsorbed charged macromolecules (positively charged polyelectrolytes of polyethylenimine) and the concentration of hydrogen peroxide (H2O2) vapor. The experimental results of functional testing of individual sensors are presented. The mechanism of the BST sensitivity to charged polyelectrolytes and H2O2 vapor has been proposed and discussed.}, language = {en} } @article{SchusserBaeckerKrischeretal.2014, author = {Schusser, Sebastian and B{\"a}cker, Matthias and Krischer, M. and Wenzel, L. and Leinhos, Marcel and Poghossian, Arshak and Biselli, Manfred and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.689}, pages = {1314 -- 1317}, year = {2014}, abstract = {A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers.}, language = {en} } @article{HuckPoghossianBaeckeretal.2014, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Reisert, Steffen and Schubert, J. and Zander, W. and Begoyan, V. K. and Buniatyan, V. V. and Sch{\"o}ning, Michael Josef}, title = {Chemical sensors based on a high-k perovskite oxide of barium strontium titanate}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.258}, pages = {28 -- 31}, year = {2014}, abstract = {High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors for liquids. In this work, BST films have been applied as a sensitive transducer material for a label-free detection of adsorbed charged macromolecules (positively charged polyelectrolytes) and concentration of hydrogen peroxide vapor as well as protection insulator layer for a contactless electrolyte-conductivity sensor. The experimental results of characterization of individual sensors are presented. Special emphasis is devoted towards the development of a capacitively-coupled contactless electrolyte-conductivity sensor.}, language = {en} } @article{PoghossianBaeckerMayeretal.2015, author = {Poghossian, Arshak and B{\"a}cker, Matthias and Mayer, Dirk and Sch{\"o}ning, Michael Josef}, title = {Gating capacitive field-effect sensors by the charge of nanoparticle/molecule hybrids}, series = {Nanoscale}, journal = {Nanoscale}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, issn = {2040-3372 (E-Journal); 2040-3364 (Print)}, doi = {10.1039/C4NR05987E}, pages = {1023 -- 1031}, year = {2015}, language = {en} } @article{SchusserPoghossianBaeckeretal.2015, author = {Schusser, Sebastian and Poghossian, Arshak and B{\"a}cker, Matthias and Krischer, M. and Leinhos, Marcel and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {An application of field-effect sensors for in-situ monitoring of degradation of biopolymers}, series = {Sensors and actuators B: Chemical}, volume = {207, Part B}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.10.058}, pages = {954 -- 959}, year = {2015}, abstract = {The characterization of the degradation kinetics of biodegradable polymers is mandatory with regard to their proper application. In the present work, polymer-modified electrolyte-insulator-semiconductor (PMEIS) field-effect sensors have been applied for in-situ monitoring of the pH-dependent degradation kinetics of the commercially available biopolymer poly(d,l-lactic acid) (PDLLA) in buffer solutions from pH 3 to pH 13. PDLLA films of 500 nm thickness were deposited on the surface of an Al-p-Si-SiO2-Ta2O5 structure from a polymer solution by means of spin-coating method. The PMEIS sensor is, in principle, capable to detect any changes in bulk, surface and interface properties of the polymer induced by degradation processes. A faster degradation has been observed for PDLLA films exposed to alkaline solutions (pH 9, pH 11 and pH 13).}, language = {en} } @article{WuBronderPoghossianetal.2014, author = {Wu, Chunsheng and Bronder, Thomas and Poghossian, Arshak and Werner, Frederik and B{\"a}cker, Matthias and Sch{\"o}ning, Michael Josef}, title = {Label-free electrical detection of DNA with a multi-spot LAPS: First step towards light-addressable DNA chips}, series = {Physica status solidi A : Applications and materials science}, volume = {211}, journal = {Physica status solidi A : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330442}, pages = {1423 -- 1428}, year = {2014}, abstract = {A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al-p-Si-SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent-voltage (I-V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I-V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.}, language = {en} } @article{BaeckerKramerHucketal.2014, author = {B{\"a}cker, Matthias and Kramer, F. and Huck, Christina and Poghossian, Arshak and Bratov, A. and Abramova, N. and Sch{\"o}ning, Michael Josef}, title = {Planar and 3D interdigitated electrodes for biosensing applications: The impact of a dielectric barrier on the sensor properties}, series = {Physica Status Solidi (A) - Applications and Materials Science}, volume = {211}, journal = {Physica Status Solidi (A) - Applications and Materials Science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330416}, pages = {1357 -- 1363}, year = {2014}, abstract = {Planar and three-dimensional (3D) interdigitated electrodes (IDE) with electrode digits separated by an insulating barrier of different heights were electrochemically characterized and compared in terms of their sensing properties. Due to the impact of the surface resistance, both types of IDE structures display a non-linear behavior in low-ionic strength solutions. The experimental data were fitted to an electrical equivalent circuit and interpreted taking into account the surface-charge-governed properties. The effect of a charged polyelectrolyte layer electrostatically assembled onto the sensor surface on the surface resistance in solutions with different KCl concentration is studied. In case of the same electrode footprint, 3D-IDEs show a larger cell constant and a higher sensitivity to molecular adsorption than that of planar IDEs. The obtained results demonstrate the potential of 3D-IDEs as a new transducer structure for a direct label-free sensing of charged molecules.}, language = {en} } @article{HuckPoghossianKerroumietal.2014, author = {Huck, Christina and Poghossian, Arshak and Kerroumi, Iman and Schusser, Sebastian and B{\"a}cker, Matthias and Zander, Willi and Schubert, J{\"u}rgen and Buniatyan, Vahe V. and Martirosyan, Norayr W. and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Multiparameter sensor chip with Barium Strontium Titanate as multipurpose material}, series = {Electroanalysis}, volume = {26}, journal = {Electroanalysis}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4109 (E-Journal); 1040-0397 (Print)}, doi = {10.1002/elan.201400076}, pages = {980 -- 987}, year = {2014}, abstract = {It is well known that biochemical and biotechnological processes are strongly dependent and affected by a variety of physico-chemical parameters such as pH value, temperature, pressure and electrolyte conductivity. Therefore, these quantities have to be monitored or controlled in order to guarantee a stable process operation, optimization and high yield. In this work, a sensor chip for the multiparameter detection of three physico-chemical parameters such as electrolyte conductivity, pH and temperature is realized using barium strontium titanate (BST) as multipurpose material. The chip integrates a capacitively coupled four-electrode electrolyte-conductivity sensor, a capacitive field-effect pH sensor and a thin-film Pt-temperature sensor. Due to the multifunctional properties of BST, it is utilized as final outermost coating layer of the processed sensor chip and serves as passivation and protection layer as well as pH-sensitive transducer material at the same time. The results of testing of the individual sensors of the developed multiparameter sensor chip are presented. In addition, a quasi-simultaneous multiparameter characterization of the sensor chip in buffer solutions with different pH value and electrolyte conductivity is performed. To study the sensor behavior and the suitability of BST as multifunctional material under harsh environmental conditions, the sensor chip was exemplarily tested in a biogas digestate.}, language = {en} } @article{HuckPoghossianBaeckeretal.2014, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Chaudhuri, S. and Zander, W. and Schubert, J. and Begoyan, V. K. and Buniatyan, V. V. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Capacitively coupled electrolyte-conductivity sensor based on high-k material of barium strontium titanate}, series = {Sensors and actuators. B: Chemical}, journal = {Sensors and actuators. B: Chemical}, number = {198}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.02.103}, pages = {102 -- 109}, year = {2014}, language = {en} } @article{LeinhosSchusserBaeckeretal.2014, author = {Leinhos, Marcel and Schusser, Sebastian and B{\"a}cker, Matthias and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Micromachined multi-parameter sensor chip for the control of polymer-degradation medium}, series = {Physica Status Solidi (A) : special issue on engineering and functional interfaces}, volume = {211}, journal = {Physica Status Solidi (A) : special issue on engineering and functional interfaces}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330364}, pages = {1346 -- 1351}, year = {2014}, abstract = {It is well known that the degradation environment can strongly influence the biodegradability and kinetics of biodegradation processes of polymers. Therefore, besides the monitoring of the degradation process, it is also necessary to control the medium in which the degradation takes place. In this work, a micromachined multi-parameter sensor chip for the control of the polymer-degradation medium has been developed. The chip combines a capacitive field-effect pH sensor, a four-electrode electrolyte-conductivity sensor and a thin-film Pt-temperature sensor. The results of characterization of individual sensors are presented. In addition, the multi-parameter sensor chip together with an impedimetric polymer-degradation sensor was simultaneously characterized in degradation solutions with different pH and electrolyte conductivity. The obtained results demonstrate the feasibility of the multi-parameter sensor chip for the control of the polymer-degradation medium.}, language = {en} } @article{SchusserMenzelBaeckeretal.2013, author = {Schusser, Sebastian and Menzel, S. and B{\"a}cker, Matthias and Leinhos, Marcel and Poghossian, Arshak and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Degradation of thin poly(lactic acid) films: characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements}, series = {Electrochimica Acta}, volume = {Vol. 113}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3859 (E-Journal); 0013-4686 (Print)}, pages = {779 -- 784}, year = {2013}, language = {en} } @article{BohrnMuchaWerneretal.2013, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and Trattner, Barbara and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and St{\"u}tz, Evamaria and Schmitt-Landsiedel, Doris and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment}, series = {Sensors and actuators. B: Chemical}, volume = {Vol. 182}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, pages = {58 -- 65}, year = {2013}, language = {en} } @article{SchusserLeinhosBaeckeretal.2013, author = {Schusser, Sebastian and Leinhos, Marcel and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200941}, pages = {905 -- 910}, year = {2013}, abstract = {Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution.}, language = {en} } @article{PoghossianWeilBaeckeretal.2012, author = {Poghossian, Arshak and Weil, M. H. and B{\"a}cker, Matthias and Mayer, D. and Sch{\"o}ning, Michael Josef}, title = {Field-effect Devices Functionalised with Gold-Nanoparticle/Macromolecule Hybrids: New Opportunities for a Label-Free Biosensing}, series = {Procedia Engineering}, journal = {Procedia Engineering}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2012.09.136}, pages = {273 -- 276}, year = {2012}, abstract = {Field-effect capacitive electrolyte-insulator-semiconductor (EIS) sensors functionalised with citrate-capped gold nanoparticles (AuNP) have been used for the electrostatic detection of macromolecules by their intrinsic molecular charge. The EIS sensor detects the charge changes in the AuNP/macromolecule hybrids induced by the adsorption or binding events. A feasibility of the proposed detection scheme has been exemplary demonstrated by realising EIS sensors for the detection of poly-D-lysine molecules.}, language = {en} }