AIT/CEST Workshop

“Bioelectrochemistry and more… ”

June 25/26, 2015 CEST Competence Center for Electrochemical Surface

Technology Viktor Kaplan Str. 2

Wiener Neustadt Austria

Speakers, Lecture Titles and Abstracts

Carbon Nanotube Chemiresistors: Inexpensive, Low Power, Sensitive Chemical Sensors

Timothy M. Swager

Massachusetts Institute of Technology Department of Chemistry

77, Massachusetts Avenue Cambridge, MA 02139

E-mail: tswager@mit.ed Carbon nanotube networks represent a powerful platform for the generation of chemiresistive sensors. Through the selective chemical functionalization with selector molecules and/or receptors, the conductance can be made selective to the presence of analytes ranging from large biological macromolecules to small gaseous molecules. This lecture will detail the fabrication of robust sensors using new functionalization chemistry to impart selectivity to the carbon nanotubes and methods to minimize drift. Sensor arrays with low levels of cross-reactivity between sensor elements will be discussed for the robust classification of chemicals. The use of carbon nanotube-based gas sensors for the detection of ethylene and other gases relevant to the monitoring fruit and produce ripeness will be presented. Gas sensors for agricultural and food production/storage/transportation are being specifically targeted and can be used to create systems that increase production, manage inventories, and minimize losses.

Stimuli Responsive Thin Films

A. Toby A. Jenkins Department of Chemistry

University of Bath Claverton Down Bath BA2 7AY

United Kingdom E-mail: a.t.a.jenkins@bath.ac.uk

The rationale of our work is to construct responsive film systems which can sense bacterial virulence factors giving a clear fluorescence / colour change and (sometimes simultaneously) release compounds which kill pathogenic bacteria. They key point here is that the systems are triggered by molecules released by the bacteria themselves: secreted virulence factors including enzymes such as hyaluronidase, peptides such as �-toxin and glycolipids. In this talk I will briefly describe the important virulence factors secreted by Staphylococcus aureus and Pseudomonas aeruginosa: specifically the Phenol Soluble Modulin (PSM) class of peptides, rhamnolipids and hyaluronidase. Three responsive film systems will be briefly summarized: 1. a dispersion of lipid vesicles within a hydrogel matrix; 2. a multi-layer polymeric film utilizing cross-linked hyaluronic acid; and 3. finally a thermally triggered PNIPAM nano-gel. System 1 detects and signals the presence of membrane lytic virulence factors via a colour change or an electrochemical response, systems 2 and 3 are designed to deliver antimicrobial therapeutics into wounds.

System 1: Phospholipid vesicles

dispersed in an agarose matrix release

self-quenched fluorescein following

membrane lysis by bacterial toxins

System 2: Two component hydrogel

system with bacteriophage release

following breakdown of hyaluronic

acid top layer by action of secreted

hyaluronidase

System 3: PNIPAM nano-gels release

bacteriophage at temperature above

the LCST

Selected references: 1. M. Laabei, W.D. Jamieson, R.C. Massey, A.T.A. Jenkins, Staphylococcus aureus

Interaction with Phospholipid Vesicles – A New Method to Accurately Determine Accessory Gene Regulator (agr) Activity, PloS One, 2014, 9, e87270.

2. M. Laabei, A.E.R. Young, A.T.A. Jenkins, In-vitro studies of Toxic Shock Toxin-1 secreting Staphylococcus aureus and implications for burn care in children, Pediatric Infectious Disease Journal. 2012, 31, e73-e77.

3. N.T. Thet, S.H. Hong, S. Marshall, M. Laabei, A. Toby, A Jenkins, Visible, colorimetric discrimination between pathogenic strains of Staphylococcus aureus and Pseudomonas aeruginosa using fluorescent dye containing lipid vesicles, Biosensors and Bioelectronics, 2013, 41, 538 -543.

4. J. Zhou, A. L. Loftus, G. Mulley, A. T. A. Jenkins, A Thin Film Detection / Response System for Pathogenic Bacteria, J. Amer. Chem. Soc. 2010, 132,, 6566–6570.

5. C. James, A.L. Johnson & A.T.A. Jenkins, Antimicrobial surface grafted thermally responsive PNIPAM-co-AA nano gels, Chem. Comm. 2011, 47, 12777-12779.

Skin Inspired Electronics Based on Organic Material s

Zhenan Bao

Department of Chemical Engineering Stanford University

381, North South Mall Stanford, CA 94305

E-mail: zbao@stanford.edu Organic and carbon nano materials are attractive for low cost electronic units for electronic skin as well as medicinal, food storage, and environmental monitoring applications. The ability to couple the sensory electrical output with on-chip signal processing can overcome the need for bulky, expensive equipment typically required for most optical detection methods. In this talk, I will present recent progress in applications of these materials and devices for skin-inspired sensors and electronics.

Electrochemical Delivery Platform of Insulin on Dem and

Sabine Szunerits Institut de Recherche Interdisciplinaire IRI, USR-3078, Parc de la Haute Borne

50 avenue de Halley, BP 70478 59658 Villeneuve d’Ascq

France Email : Sabine.Szunerits@iri.univ-lille1.fr

Diabetes is characterized by insufficient insulin plasma level to meet the organism demand. In type 1 diabetes, absolute deficiency of insulin production results from massive auto-immune destruction of pancreatic beta cells. For this reason, the main therapy consists in delivering exogenous insulin. The treatment methods require numerous daily injections of insulin administered by subcutaneous needle injection, insulin pen and catheters connected to insulin pumps. These methods are however both painful and inconvenient. There is thus an increasing demand for the design of new insulin administration systems and this has led to the investigations of oral, nasal, buccal, pulmonary, rectal, ocular and transdermal routes. Transdermal delivery of insulin has been recently proposed as a viable alternative allowing the controlled release of insulin over time together with high patience compliance.1 While transdermal delivery is limited by the low permeability of the stratum corneum, the skin’s outermost layer, skin permeation can be enhanced through electrical activation. In this presentation, the advantage of flexible electrodes modified with reduced graphene (rGO) and loaded with insulin,2-3 to electrically trigger insulin release over time will be presented. A special focus will be on the development of insulin-impregnated conductive matrixes and the influence of potential and current on the biological activity of released insulin. References : S. I. Hadebe, P. S. Nhubane, M. R. Serumula, C. T. Musabayane, PLOS one, 2014, 9, e1014461. I. Kaminska, M. R. Das, Y. Coffinier; J. Niedziółka-Jönsson, P. Woisel, M. Opallo, S. Szunerits, R Boukherroub, Chem. Commun. 2012, 48, 1221-1223 (cover page) K. Turcheniuk, M. Khanal, A. Montorina, P. Subramanian, A. Barras, V. Zaitsev, V. Kuncer, A. Leca, A. Martoriati, K. Cailliau, J.-F. Bodart, R. Boukherroub, S. Szunerits RSC Adv. 2014, 4 (2) 865-875.

Dielectric and Semiconductor Surface Interfacial In teractions for Chemical and Biochemical Sensing Using Organic Elec tronics

Howard Katz, Kalpana Besar, Deepa Madan, Jennifer Dailey, Weiguo Huang,

and Karim Abdou Diallo Department of Materials Science and Engineering

Johns Hopkins University Whiting School of Engineering

Maryland Hall 206 3400, North Charles Street Baltimore, MD 21218-2608

E-mail: hekatz@jhu.edu

Surface dipole and charge density modulations resulting from chemical binding to electronic material interfaces lead to electronic responses in field effect and chemoresistive devices. This talk will discuss two different pathways toward maximum chemical sensitivity for small molecule (vapor) sensing and for biomacromolecule (protein) sensing. The first pathway is to increase the semiconductor surface accessibility, its analyte binding capability, and the match in charge carrier energy level with vapor analyte molecular orbitals to increase the transduction of molecular adsorption to a conductivity change. We use such strategies to achieve ten-ppb detection of ammonia for the purpose of correlating its environmental concentration with adverse health effects. The second pathway is to modify the compositions of top dielectric capacitive coupling layers, comprising hydrocarbon and fluorinated polymers and attachment groups, so that the change in ion distribution resulting from the presence of bound proteins exerts the maximum field effect on an organic semiconductor lying under the coupling layer. We detect ng/mL levels of the brain injury biomarker GFAP with this strategy, the highest protein sensitivity reported for an organic transistor, as well as opposite polarity responses in the two legs of a complementary (n and p semiconductor) inverter circuit. Use of printable materials in these technologies will be emphasized.

Analysis of Macromolecules at Electrolyte/Solid Int erfaces

Adrian Keller, Guido Grundmeier Technische und Makromolekulare Chemie

Universität Paderborn Warburger Str. 100 D-33098 Paderborn

Germany Email: g.grundmeier@tc.uni-paderborn.de

The interaction of biological systems with artificial and natural materials plays an important role in many disciplines, ranging from medical implants to biomolecular nanotechnology. Understanding and ultimately controlling the processes and reactions at these biointerfaces requires a complementary interface science approach that takes into account the complexity of the interfaces resulting from the adsorption of organic molecules and macromolecules. Atomic Force Microscopy and optical spectroscopy allow for an in-situ analytical analysis of structures and processes at electrolyte/solid interfaces and of the molecular organization of biological nanomaterials. Moreover, such techniques can be combined with electrochemical analysis or performed under electrochemical control. The presentation provides an overview on how structures, forces and processes can be analyzed by means of combined microscopic, spectroscopic and electrochemical methods. Biomaterials interfaces and DNA-based nanostructures are selected for the illustration of the analytical approach.

Protein Electrochemical Oxidation

Ana Maria Oliveira-Brett Department of Chemistry, Faculty of Sciences and Technology,

University of Coimbra 3004-535 Coimbra

Portugal E-mail: brett@ci.uc.pt

Proteins are essential components of organisms and are involved in a wide range of biological functions. However, electrochemical studies in qualitative and quantitative analysis in proteomics of individual protein domains and mutants of proteins, not containing a centre with fast-reversible redox reactions, are still very few. The adsorption of native proteins without prosthetic groups on a solid electrode surface is weaker due to the rigidity of the 3D-structure, which makes electron transfer between the electroactive amino acids in the interior of the proteins and the electrode surface more difficult. Only tyrosine, tryptophan, histidine, cysteine and methionine residues are oxidized on carbon electrodes in aqueous solution and all present a pH-dependent electron transfer mechanism. Protein direct electron transfer reactions at carbon electrodes, glassy carbon and boron doped diamond electrode surfaces, of the enzyme peptide methionine sulfoxide reductase A (MsrA), and monoclonal antibody rituximab (RTX), were investigated. MsrA is a ubiquitous protein, highly conserved, one of the major targets of reactive oxygen species, an antioxidant repair enzyme which reduces oxidized methionine to methionine, preventing irreversible protein damage and, as a consequence, extending the organism's life span. RTX is a human/murine chimeric monoclonal antibody that specifically targets the transmembrane protein CD20 of B cells, already approved for the treatment of low-grade non-Hodgkin's B cell lymphomas, and the RTX-DNA interaction was also investigated using a dsDNA-electrochemical biosensor. The interaction of proteins with solid electrode surfaces is not only a fundamental phenomenon but also a key to several important and novel applications in biosensors, biotechnology, medical devices and drug-delivery schemes.

Multimodal Sensing by Organic Field Effect Devices: Chemical,

Physical, Biosensing with the Same Sensing Platform

Stefano Lai1, Andrea Spanu1,Piero Cosseddu3, Mariateresa Tedesco2, Sergio Martinoia2, Annalisa Bonfiglio 1,3

1Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, 09123 Cagliari, Italy,

2Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genova, Via Opera Pia, 13 - 16145 Genova, Italy,

3CNR – Institute of Nanoscience, S3 Centre, Via Campi 213A, 41125, Modena Italy

E-mail: annalisa@diee.unica.it Organic, charge-modulated Field Effect Transistors (OCMFETs) have been proposed since some time and have shown so far very interesting results in a variety of sensing tasks, both for chemical and physical variables, as well as, more recently, for the detection of the electrical activity of cells. The core of the device is a floating gate organic transistor, capable to be operated at low voltages thanks to an ultra-thin, hybrid dielectric which can be fabricated over large areas at high yields. The sensitivity of the device is obtained by anchoring in a part of the floating gate a sensing layer (that, according to the application, may be, for instance, a probe molecular layer or an element dedicated to the transduction of a physical signal into an electrical charge as a piezoelectric layer) directly exposed to the measurement environment. In addition to the possibility of applying this measurement principle to a variety of applicative fields, by simply changing the kind of sensing layer immobilized on the floating gate, an important achieved result is the possibility to have precise design rules for adapting the concept to the specifications imposed by the application, thus enabling the design of a dedicated device architecture with predictable performances. Several examples of this approach will be given, including also multi-modal sensing, i.e. the ability to sense several different parameters with an array of similar devices.

Responsive Polymer Architectures - From Hydrogels t o Sensors

Ulrich Jonas Macromolecular Chemistry

University of Siegen Adolf-Reichwein-Strasse 2, D-57076 Siegen

Germany E-Mail: jonas@chemie.uni-siegen.de

The term "reconfigurable" or "programmable" soft matter represents an emerging concept in science and technology, where the chemical, physical and functional properties of materials can be switched between well-defined states by external stimulation, for example by temperature changes or by irradiation with light. Manifold examples are found in the animate nature, such as phototaxis of plants (like the head of the sunflower following the sun), and at present the challenge in research aims at harnessing such powerful behavior in artificial matter by merging the specific responsive functionality of molecules with a complex structural hierarchy. Towards this aim we have synthesized a range of thermoresponsive, watersoluble polymers with either a lower critical- (LCST) or an upper critical solution temperature (UCST) by controlled radical polymerization methods. By means of the controlled polymerization method (RAFT and ATRP) specific end group functionalizations can be achieved. Upon variation of the temperature these polymers show a characteristic transition of their solubility and consequently of the coil dimensions in the aqueous phase, becoming soluble above their UCST, or insoluble above the LCST due to polymer coil collapse. Concomitantly, the aggregation state and superstructure formation (micellar and vesicular aggregates) depends on the external stimulus. The different polymers were also endowed with photoreactive groups that allow crosslinking upon irradiation with light. This photocrosslinking strategy enables immobilization of the transient state when changing external conditions. Furthermore, azobenzene-containing polymers as photoresponsive systems where synthesized with the photocrosslinker units to test the possibility of simultaneous photoswitching and photocrosslinking in dependence of the irradiation wavelength. With the thermoresponsive system we synthesized block copolymer architectures in order to merge the LCST- and UCST behavior in one single molecule while allowing crosslink upon irradiation in their specific thermal switching states. From these polymers various hydrogel layer architectures could be realized that find application as responsive sensor matrix with high binding capacity in optical sensor platforms based on surface plasmon resonance or Bloch surface waves. During our studies we found by dynamic light scattering that already the simple PNIPAAm polymer showed a complex aggregation behavior, which specifically depended on the end group functionalization. Details of the various synthesis strategies and characterization results will be presented, and a hypothetical model of the structure-behavior relationship will be discussed based on the hydrophilic-hydrophobic balance of the end groups with the polymer chain.

Biosensors and biofuel cells based of redox hydroge ls

Wolfgang Schuhmann Analytical Chemistry - Center for Electrochemical Sciences (CES)

Ruhr-Universität Bochum, Universitätstr. 150 D-44780 Bochum

Germany E-mail: wolfgang.schuhmann@rub.de

Redox polymers are frequently used for wiring biological recognition elements such as e.g. enzymes with electrode surfaces. Evidently, for the design of biosensors, biofuel cells or biobatteries the adaptation of the redox potential of the polymer bound redox species to the formal potential of the prosthetic group in the active site of the enzyme is of high importance. Moreover, the polymer backbone structure has to be modified to allow for high mobility of the polymer-bound redox relays, swelling of the hydrogel etc. The following aspects will be discussed: 1. Os-complex and phenothiazine-modified redox polymers for wiring of cellobiose dehydrogenase, glucose oxidase and PQQ-dependent glucose dehydrogenase 2. Design and optimization of photobioelectrochemical devices based on photosystem 1 and photosystem 2 3. Viologen-based redox polymers for wiring of Ni-Fe-hydrogenase 4. Bioelectrocatalytic amplification in amperometric biosensors 5. Self-powered bioelectrocatalytic devices

Highly Sensitive Electrochemical and Electrochemilu minescent Detection of Celiac Disease Biomarkers at Gold Nano electrode

Ensembles

Henok B. Habtamua,b, Milica Senticb,c, Luigina De Leod, Tarcisio Notd, Neso Sojicb, Paolo Ugo a,*

a Department of Molecular Sciences and Nanosystems, University Ca’Foscari of Venice, S. Marta 2137, 30123 Venice, Italy

b Institut des Sciences Moléculaires, University of Bordeaux, ENSCBP. 33607 Pessac, France

c University of Belgrade, Faculty of Chemistry, 11000 Belgrade, Serbia d Institute of Child Health IRCCS “Burlo Garofolo”, 34100, Trieste, Italy

*E-mail: ugo@unive.it Celiac disease (CD) is a gluten-dependent autoimmune disorder occurring in individuals carrying the human leucocyte antigen (HLA) DQ2-DQ8 molecules, with a prevalence of 1% in the general population. The clinical condition of CD vary from mild to severe, and some patients with celiac disease can be asymptomatic for years. The later the diagnosis of CD, the more likelihood of serious illness and excess mortality. Early diagnosis and treatment with gluten-free diet (GFD), reduces mortality and the prevalence of CD-associated disorders. Although definitive diagnosis of CD is still based on histological changes in small intestinal mucosa, serological test for CD screening based on detection of anti-transglutaminase type-2 antibodies (anti-TG) are less invasive, with excellent sensitivity (98%) and specificity (95%). Rapid tests might greatly help the physician to make a preliminary diagnosis of CD in poor countries where diarrheal disease and malnutrition are common. In this contest, making diagnosis of CD easier thanks to the use of suitable biosensors would make a significant contribution to reduce morbidity and mortality, particularly when the CD-diagnosis is not yet considered. With this goal, in this communication we present the development of a sensitive and specific immunosensor based on functionalized ensembles of nanoelectrodes (NEEs) prepared by electroless deposition of Au in pores of track-etched polycarbonate (PC) filter membrane. The sensor employs tTG as biorecognition layer which is immobilized on the PC of the NEEs by exploiting the high affinity of PC for proteins. The captured analyte, namely, anti-TG, is then reacted with a secondary antibody labeled alternatively with a redox enzyme or with Ru(bpy)32+; we used the former label for electrochemical (voltammetric) detection and the latter for electrochemically induced luminescent detection. Comparison between the two detection schemes is discussed also on the basis of the results achieved by analyzing human serum samples.

Smart, redox responsive organometallic polymer plat forms in sensing and release and as metal nanoparticle found ry

G. Julius Vancso

University of Twente MESA+ Research Institute for Nanotechnology

7500 AE Enschede The Netherlands

E-mail: g.j.vancso@utwente.nl Redox responsive natural macromolecules, including enzymes and proteins, play a pivotal role in life. Biomedical and other applications of artificial, redox responsive polymeric systems have been limited due to limited access to such synthetic molecules. Emerging poly(ferrocenylsilanes) (PFS), featuring ferrocene units connected by functionalized silane groups in the main chain, constitute a versatile class of smart organometallic polymers with many useful applications ranging from biosensing, smart membranes, adhesion and friction control, programmed molecular release and as “in-situ” redox reactors for controlled production of metal nanoparticles. In this lecture first a brief overview of PFS synthesis, and structure-property relations will be provided. Special attention will be paid to hydrogels, and hydrogel shaping by microfluidic devices, layer-by-layer assemblies, and thin film processing. Applications of PFS for electrode decoration in sensing, including electro-grafting, will be elucidated. Covalent layer-by-layer assembly yielding PFS multilayers and the use of such layers in glucose sensing will be discussed. Given that PFS has an oxidation potential of around + 0.4 V, it can reduce metal ions to metal nanoparticles when the PFS chains act as a reducing agent. We shall introduce a new metal nanoparticle foundry based on PFS hydrogels, which yield metal nanoparticles with sizes ranging from a few nm to tens of nm-s, without the necessity of using external reducing agents. We demonstrate the universality of the reduction capability of such hydrogels. Potential applications will be sketched, ranging from metal nanoparticle supported catalysis by utilizing fluidic microreactors, to sensing and optoelectronics.

For a review see: X.F. Sui, X.L. Feng, M.A. Hempenius, G.J. Vancso, Redox active gels: Synthesis, structures and applications. J. Mater. Chem. B, 1(12):1658-1672, 2013.