- Email: [email protected]
Sensing shows the way forward – from principles to applications
Meeting reports
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
Meeting reports Sensing shows the way forward – from principles to applications Report on the Seventh European Conference on Optical Chemical Sensors and Biosensors: Europt(r)ode VII, held in Madrid, Spain, 4–7April 2004
€nter Gauglitz Gu
1. Introduction Europt(r)ode VII was organised by Guillermo Orellana and Marıa C. Moreno-Bondi at the Universidad Complutense de Madrid. Since the first Europt(r)ode in Graz, this conference has been held in different European countries every two years, and has turned out to be the most interesting optical sensor conference in Europe; it is therefore attended by many visitors from many different countries, especially with US American colleagues joining their European colleagues each time. At this conference, the latest results in the fields of new materials and principles for optical chemical sensing and biosensing, novel optoelectronics instruments and components for sensor development, integrated optical systems, micro, nano and multiplex sensors, optosensing arrays for genomics and proteomics, and applications in many fields were presented. Optical applications for chemical monitoring now range from environmental quality assurance, process control, food analysis, medical diagnostics, biosphere investigations to extra-terrestrial research. All these different optical principles and the various applications were presented in six plenary lectures, 11 invited lectures, and 38 selected additional oral presentations. In addition, 132 posters were accepted to give up-to-date results in optical, chemical and biosensing research. More than
Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 8, D-72076 Tuebingen, Germany. Tel.: +49-7071-29-76927; Fax: +49-7071-295490; E-mail: [email protected]
xii
250 participants enjoyed the perfect organisation, the wonderful lecture halls, the optimal conditions for presenting posters and opportunities to visit industrial presentations. One of the main events of this meeting was the presentation of the Roche award to E. Bakker from Auburn University for his many years of work on ionophorebased optodes, miniaturisation and parallelisation, combining development in optical transduction techniques and improvement of sensitive layers.
2. Plenary lectures Plenary lectures covered recent areas of research and highlights in the present development of sensors, and demonstrated the profound interest in applications. The first was given by K. Cammann (University of Munster, Germany), demonstrating a novel view of 40 years of biosensor research and presenting the application of an optical DNA array chip based on evanescent field excitation. It included fluorescence monitored by CCD camera, improvement in feasibility and validation in the area of real food reference samples, and simple, rapid detection of micro-organisms, It was a good introduction to the huge impact of optical sensing on research and applications [1]. U.J. Krull (University of Toronto, Canada) addressed the problem of DNA biosensors and biochips, exploring the use of a matrix isolation method, producing the desired environment for the probe molecules. This gradient-resolved information platform (GRIP) is based on a surface coated with a continuous gradient of density, sequence, orientation, or structure of DNA strands [2]. 0165-9936/$ - see front matter doi:10.1016/S0165-9936(04)00738-1
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
Luminescence in general, and especially photoluminescence-based optical sensors, have enjoyed a high growth rate in the last few years because of high sensitivity and high selectivity. Therefore, A. Sanz-Medel (University of Oviedo, Spain) could demonstrate improvement in optosensing of PAHs using room temperature phosphorescence [3]. Genetic engineering in biosensing using micro or nanoanalytical methods was demonstrated in an impressive lecture by S. Daunert (University of Texas, USA). In a mixture of present and anticipated results, the potential of future biosensors became obvious [4]. The ideas presented fitted quite well into the forthcoming European programme of biosensing in health and environment. K. Suzuki (University of Keio, Japan) gave a survey of the past, present and future of ionophore-based optosensing. The objective is to obtain smart chemical-sensor systems by combining hardware and software in research with instrument-development and data-mining approaches [5]. In a more application-oriented lecture, U.E. SpichigerKeller (Institute of Technology, Zurich, Switzerland) demonstrated the secret of low detection limits using optodes. She mentioned attractive features of optical sensing using different transduction elements for various applications, depending on the quality of engineering chemistry and tailoring receptor molecules [6].
3. Invited lectures Each of the sessions was opened by an invited lecture introducing the field to be covered in oral presentations. Parallel sessions were scheduled, but it was possible to attend all of the oral presentations. Only of few of these can be mentioned below. For further details please see the book of abstracts [7]. The session on biochips was opened with a lecture by F. Bier (Fraunhofer Institute, Germany) on optical detection of DNA-modifying enzymes on immobilised substrates, stating the state of the art in parallel detection using fluorophore-labelled and non-labelled systems [8]. Other oral presentations described the revolutionising of the biochip technology by signal enhancement of protein chips (U. Sauer, ARC Seibersdorf Res. GmbH, Austria). There are different approaches to immobilised sensitive layers (S. Jiang, University of Washington, USA), and, in many cases, surface plasmon resonance is used as a specific tool (B.A. Russell, University of East Anglia, UK). Recent developments in transducers based on planar integrated optical waveguides were outlined in the second session by S.S. Saavedra (University of Arizona, USA), using his waveguides for internal total reflection
Meeting reports
or giving a new concept by developing a broadband technology for creating a single-mode electrochemically active planar waveguide platform, combining optical and electrochemical sensing [9]. In this session, further approaches using different waveguide types (material, refractive index) and read-out techniques were discussed. Another session was dedicated to optical detection in microfluidic systems. Microfluidic structures were fabricated in polymer technology using polydimethyl siloxane (PDMS) as A. Dybko (Warsaw, Poland) [10] discussed with respect to coupling efficiency for absorbance and fluorescence samples in various experiments. In parallel, integrated optical sensors were presented. Integrated waveguide absorbance optodes and integrated waveguide fluorescent optodes can be used as a basic transducer for a variety of compounds. In the invited lectures, new classes of visible and near-infrared chromoionophores were presented, allowing a wide range of applications (J. Alonso, Universidad Aut onoma de Barcelona, Spain) [11]. Integrated waveguides can be considered as a basis for direct optical detection techniques using label-free approaches – as demonstrated with examples for proteins (C. Hoffmann, Fraunhofer Institute, Freiburg, Germany) – or micro refractometry, another approach in comparison with surface plasmon resonance (R.E. Kunz, CSEM, Neuch^atel, Switzerland) [12]. Techniques for measuring the composition of the intra-cellular environment are important for an understanding of the mechanisms of cell function and cell behaviour. The development of nanosensors selective to glucose, oxygen, zinc, and calcium allows strategies for measuring analytes in the intra-cellular environment (J.W. Aylott, University of Hull, UK) [13]. Another lecture in this session by T. Vo-Dinh (Oak Ridge National Laboratory, USA) [14] demonstrated recent results of nanosensors for monitoring molecular signalling pathways in a single living cell. For this purpose, surface-enhanced Raman scattering and nanosensors for in vivo analysis of single cells have been developed. The first results for such an approach were presented. Dynamic fluorescence measurements were used to determine the concentration of living immobilised cells (O. Podrazky, Academy of Sciences of the Czech Republic) [15]. Further improvement in array biosensors for food safety could be demonstrated by F.S. Ligler (Washington, DC, USA) [16]. This multi-analyte approach was discussed by a group in Dublin; O. McGaughey used waveguides and stamp printing or pin printing and simple light emitting diode (LED) as an excitation source. This means major requirements for the fields such as food and environmental quality controls as well as biomedical diagnostics could be met [17]. Confocal total http://www.elsevier.com/locate/trac
xiii
Meeting reports
internal reflection fluorescence (TIRF) microscopy was used to detect single-molecule hybridisation at surfaces (T. Ruckstuhl, University of Zurich, Switzerland) [18]. Another invited lecture was dedicated to chemosensing and started with a lecture by G.J. Mohr (University of Jena, Germany) [19], in which he discussed chromoand fluoro-reactands as indicator dyes that allow the optical detection of electrically neutral analytes and quality with respect to response times, and operational and shelf life. A typical application of chemical interaction processes was presented by S. Busche (University of Tuebingen, Germany), who demonstrated enantiomeric separation by polymeric chirasil-calix layers with optical sensing devices [20]. The technical session was introduced by a survey of the commercial status of planar waveguide technologies with DNA and protein microarrays coming from Zeptosens in Switzerland [21]. In this session, companies taking part in the industrial exhibition presented results from this field of application, namely Osmetech, Ocean Optics, Interlab, and Biacore. Fluorescent nanocrystals as ultra-bright time resolved sensors were presented by a group from Grenoble, France (R.B. Pansu) [22], spin-coating a mixture of fluorescent dye with a silane precursor over microscope cover slips. Time-resolved laser-induced fluorescence measurements can provide high spatial and temporal resolution for the determination of contaminants (e.g., in coastal sea water) (R.F. Chen, Boston, USA) [23]. In situ fluorescence sensors have been developed by the environmental coastal and ocean sciences at the University of Massachusetts, using a fibre optic fluorescence sensor system. For some years, molecular imprinting has been considered as a new approach for optical sensing, combining high stability with a certain degree of selectivity, attempting to substitute biomolecular layers. Recent developments were presented by S. Piletsky (Cranfield University, UK) [24]. Incorporating reactive dyes into molecularly imprinted polymers will result in highly sensitive optochemical sensors, as demonstrated by K. Haupt (Compiegne University of Technology, France) [25]. Oxygen is seen as an essential molecule in many applications in life sciences by technology and medicine. Luminescence quenching is a method to determine the oxygen constant, and D.B. Papkovsky (University College Cork, Ireland) [26] lectured on a newly developed cell-respirometric screening technology that allows high through-put screening applications, low volume and high sensitivity platforms, and the monitoring of respiration of small organisms and single cells. In this session, applications for water analysis were presented, such as the automatic water analyser computer supported system (AWACSS) by G. Proll (University of Tuebingen, Germany) [27], who demonxiv
http://www.elsevier.com/locate/trac
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
strated extremely low limits of detection in real water samples. The water sensing application using IR-ATR spectroscopy by G.T. Dobbs [28] involved in situ monitoring in a harsh aquatic environment. Another approach to monitoring sea water using fibre-optic optodes was presented by A. Gonz ales-Cano, who took care of the problems of salinity, temperature and pressure [29].
4. Conclusion The two parallel sessions often meant that participants were forced to choose between two interesting lectures. However, the large number of posters, which, in many cases, added to the lectures allowed all visitors to get a wonderful survey of the present state of the art in optical sensing regarding transduction technology, various sensitive layers and applications. The involvement of industry in attending the meeting, taking part in the exhibition and giving technology-oriented lectures demonstrated the high degree of interest of the community in the results in optical sensing. Europt(r)ode has gained scientific standing and attracted interest from industry because of the application-oriented oral presentations and posters. It was especially gratifying to meet young scientists and graduate students attending the poster sessions. It resulted in long discussions, even preventing participants from enjoying time in the cultural centre of Madrid. This conference is successful, and will be next held when Europt(r)ode VIII takes place in Tuebingen, Germany, 2–5 April 2006 [30].
References [1] K. Cammann, Phys. Chem. Chem. Phys. 5 (2003) 5159. [2] D. Erickson, D. Li, U.J. Krull, Anal. Biochem. 317 (2003) 186. [3] J.F. Fernandez-Sanchez, A. Segura-Carretero, J.M. Costa-Fernandez, N. Bordel, R. Pereiro, C. Cruces-Blanco, A. Sanz-Medel, A. Fernandez-Gutierrez, Anal. Bioanal. Chem. 377 (2003) 614. [4] S.K. Deo, E.A. Moschou, S.F. Peteu, L.G. Bachas, S. Daunert, P.E. Eisenhardt, M.J. Marc, Anal. Chem. 75 (2003) 206A. [5] S. Sasaki, S. Ozawa, D. Citterio, K. Yamada, K. Suzuki, Talanta 63 (2004) 131. [6] G.J. Mohr, G. Zhylyak, T. Nezel, U.E. Spichiger-Keller, N. Kerness, O. Brand, H. Baltes, U.W. Grummt, Anal. Sci. 18 (2002) 109. [7] Book of Abstracts for the Seventh European Conference on Optical Chemical Sensors and Biosensors: Europt(r)ode VII, Madrid, Spain, 2004. [8] N. Gajovic-Eichelmann, E. Ehrentreich-Forster, F.F. Bier, Biosens. Bioelectron. 19 (2003) 417. [9] J.T. Bradshaw, S.B. Mendes, N.R. Armstrong, S.S. Saavedra, Anal. Chem. 75 (2003) 1080. [10] D. Stadnik, A. Dybko, Analyst (Cambr., UK) 128 (2003) 523.
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004 [11] M. Puyol, S. Miltsov, I. Salinas, J. Alonso, Anal. Chem. 74 (2002) 570. [12] K. Cottier, M. Wiki, G. Voirin, H. Gao, R.E. Kunz, Sensors Actuators B 91 (2003) 241. [13] J.W. Aylott, Analyst (Cambr., UK) 128 (2003) 309. [14] L.R. Allain, T. Vo-Dinh, Anal. Chim. Acta 469 (2002) 149. [15] R. Vankova, G. Kuncova, O. Podrazky, A. Gaudinova, Th. Vanek, Hemijska Industrija 57 (2003) 632. [16] F.S. Ligler, C.A. Rowe Taitt, L.C. Shriver-Lake, K.E. Sapsford, Y. Shubin, J.P. Golden, Anal. Bioanal. Chem. 377 (2003) 469. [17] S. Aubonnet, H.F. Barry, C. von Bueltzingsloewen, J.-M. Sabattie, B.D. MacCraith, Electron. Lett. 39 (2003) 913. [18] T. Ruckstuhl, M. Rankl, S. Seeger, Biosens. Bioelectron. 18 (2003) 1193. [19] G.J. Mohr, Sensors Actuators B 90 (2003) 31. [20] B. Kieser, C. Fietzek, R. Schmidt, G. Belge, U. Weimar, V. Schurig, G. Gauglitz, Anal. Chem. 74 (2002) 3005.
Meeting reports [21] Patent Application WO 2003-EP10626 20030924; PCT Int. Appl. 2004, J. Schrenzel, P. Francois, Y. Charbonnier, J.G. Jacquet, D. Utinger, G.M. Kresbach, A. Abel, M. Ehrat. [22] L. Choutteton, P. Denjean, R.B. Pansu, Phys. Chem. Chem. Phys. 1 (1999) 2463. [23] R.F. Chen, Y. Zhang, P. Vlahos, S.M. Rudnick, Top. Stud. Oceanogr. 49 (2002) 4439. [24] I. Chianella, S.A. Piletsky, I.E. Tothill, B. Chen, A.P.F. Turner, Biosens. Bioelectron. 18 (2003) 119. [25] K. Haupt, Anal. Chem. 75 (2003) 376A. [26] J. Hynes, S. Floyd, A. Soini, R. O’Connor, D.B. Papkovsky, J. Biomol. Screen. 8 (2003) 264. [27] J. Tschmelak, M. Kumpf, G. Proll, G. Gauglitz, Anal. Lett. 37 (2004) 1701. [28] B. Mizaiko, Anal. Chem. 75 (2003) 258A. [29] European project MISPEC, EVK3-2000-00519. [30] Available from:.
Quality adopted throughout speciation Report on the Third International Conference on Trace Element Speciation in Biomedical, Nutritional and Environmental Sciences, held in Neuherberg, Germany, 10–13 May 2004
Bernhard Michalke *, Peter Schramel 1. Introduction The Third Speciation Conference, held at the GSF National Research Center for Environment and Health, was the third in this series, which started in 1998, and was also a continuation of the six ‘‘International Workshops on Trace Element Analytical Chemistry in Medicine and Biology’’ that were held at GSF between 1980 and 1990.
chemistry used for speciation’’ were selected as new fields. Again, the use of speciation throughout, in the sense of Templeton et al. [1], was stressed. To provide a scientific framework, eight sessions were planned, each introduced by a plenary lecture delivered by experienced scientists in their respective fields and chaired by colleagues well known in speciation (Table 1). 3. Results
2. Aims The Third Speciation Conference generally aimed to highlight the state of the art in element speciation and to show the ‘‘hot spots’’ in this field. Topics that were of greater interest in 2001 were selected as well as others, which had been recognized in the last three years to be of future interest. Such topics were ‘‘Increased use of quality-control approaches’’ and ‘‘Investigations on species preservation during extraction procedures for handling solid samples’’. In addition, ‘‘Speciation in clinical chemistry’’ and ‘‘Techniques from organic *Corresponding author. E-mail: [email protected]
0165-9936/$ - see front matter
doi:10.1016/S0165-9936(04)00737-X
Our invitation to contribute to this conference was accepted by about 110 participants from 30 countries all over the world, of which 65 contributed with a lecture or a poster presentation. For evaluation of the contributions, the scientific committee strictly followed the definitions about speciation [1], so they were not discussed as they were already accepted as a basis during the conference. Fig. 1 shows an overview of the number of contributions per topic, also in comparison with previous Speciation Conferences. However, it must be noted that a considerable number of papers covered more than one topic (e.g., many were applying quality control (QC) experiments to their investigations, which were assigned to different topics, so QC in speciation (as such and ‘‘hidden’’ in other topics) xv
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
Meeting reports Sensing shows the way forward – from principles to applications Report on the Seventh European Conference on Optical Chemical Sensors and Biosensors: Europt(r)ode VII, held in Madrid, Spain, 4–7April 2004
€nter Gauglitz Gu
1. Introduction Europt(r)ode VII was organised by Guillermo Orellana and Marıa C. Moreno-Bondi at the Universidad Complutense de Madrid. Since the first Europt(r)ode in Graz, this conference has been held in different European countries every two years, and has turned out to be the most interesting optical sensor conference in Europe; it is therefore attended by many visitors from many different countries, especially with US American colleagues joining their European colleagues each time. At this conference, the latest results in the fields of new materials and principles for optical chemical sensing and biosensing, novel optoelectronics instruments and components for sensor development, integrated optical systems, micro, nano and multiplex sensors, optosensing arrays for genomics and proteomics, and applications in many fields were presented. Optical applications for chemical monitoring now range from environmental quality assurance, process control, food analysis, medical diagnostics, biosphere investigations to extra-terrestrial research. All these different optical principles and the various applications were presented in six plenary lectures, 11 invited lectures, and 38 selected additional oral presentations. In addition, 132 posters were accepted to give up-to-date results in optical, chemical and biosensing research. More than
Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 8, D-72076 Tuebingen, Germany. Tel.: +49-7071-29-76927; Fax: +49-7071-295490; E-mail: [email protected]
xii
250 participants enjoyed the perfect organisation, the wonderful lecture halls, the optimal conditions for presenting posters and opportunities to visit industrial presentations. One of the main events of this meeting was the presentation of the Roche award to E. Bakker from Auburn University for his many years of work on ionophorebased optodes, miniaturisation and parallelisation, combining development in optical transduction techniques and improvement of sensitive layers.
2. Plenary lectures Plenary lectures covered recent areas of research and highlights in the present development of sensors, and demonstrated the profound interest in applications. The first was given by K. Cammann (University of Munster, Germany), demonstrating a novel view of 40 years of biosensor research and presenting the application of an optical DNA array chip based on evanescent field excitation. It included fluorescence monitored by CCD camera, improvement in feasibility and validation in the area of real food reference samples, and simple, rapid detection of micro-organisms, It was a good introduction to the huge impact of optical sensing on research and applications [1]. U.J. Krull (University of Toronto, Canada) addressed the problem of DNA biosensors and biochips, exploring the use of a matrix isolation method, producing the desired environment for the probe molecules. This gradient-resolved information platform (GRIP) is based on a surface coated with a continuous gradient of density, sequence, orientation, or structure of DNA strands [2]. 0165-9936/$ - see front matter doi:10.1016/S0165-9936(04)00738-1
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
Luminescence in general, and especially photoluminescence-based optical sensors, have enjoyed a high growth rate in the last few years because of high sensitivity and high selectivity. Therefore, A. Sanz-Medel (University of Oviedo, Spain) could demonstrate improvement in optosensing of PAHs using room temperature phosphorescence [3]. Genetic engineering in biosensing using micro or nanoanalytical methods was demonstrated in an impressive lecture by S. Daunert (University of Texas, USA). In a mixture of present and anticipated results, the potential of future biosensors became obvious [4]. The ideas presented fitted quite well into the forthcoming European programme of biosensing in health and environment. K. Suzuki (University of Keio, Japan) gave a survey of the past, present and future of ionophore-based optosensing. The objective is to obtain smart chemical-sensor systems by combining hardware and software in research with instrument-development and data-mining approaches [5]. In a more application-oriented lecture, U.E. SpichigerKeller (Institute of Technology, Zurich, Switzerland) demonstrated the secret of low detection limits using optodes. She mentioned attractive features of optical sensing using different transduction elements for various applications, depending on the quality of engineering chemistry and tailoring receptor molecules [6].
3. Invited lectures Each of the sessions was opened by an invited lecture introducing the field to be covered in oral presentations. Parallel sessions were scheduled, but it was possible to attend all of the oral presentations. Only of few of these can be mentioned below. For further details please see the book of abstracts [7]. The session on biochips was opened with a lecture by F. Bier (Fraunhofer Institute, Germany) on optical detection of DNA-modifying enzymes on immobilised substrates, stating the state of the art in parallel detection using fluorophore-labelled and non-labelled systems [8]. Other oral presentations described the revolutionising of the biochip technology by signal enhancement of protein chips (U. Sauer, ARC Seibersdorf Res. GmbH, Austria). There are different approaches to immobilised sensitive layers (S. Jiang, University of Washington, USA), and, in many cases, surface plasmon resonance is used as a specific tool (B.A. Russell, University of East Anglia, UK). Recent developments in transducers based on planar integrated optical waveguides were outlined in the second session by S.S. Saavedra (University of Arizona, USA), using his waveguides for internal total reflection
Meeting reports
or giving a new concept by developing a broadband technology for creating a single-mode electrochemically active planar waveguide platform, combining optical and electrochemical sensing [9]. In this session, further approaches using different waveguide types (material, refractive index) and read-out techniques were discussed. Another session was dedicated to optical detection in microfluidic systems. Microfluidic structures were fabricated in polymer technology using polydimethyl siloxane (PDMS) as A. Dybko (Warsaw, Poland) [10] discussed with respect to coupling efficiency for absorbance and fluorescence samples in various experiments. In parallel, integrated optical sensors were presented. Integrated waveguide absorbance optodes and integrated waveguide fluorescent optodes can be used as a basic transducer for a variety of compounds. In the invited lectures, new classes of visible and near-infrared chromoionophores were presented, allowing a wide range of applications (J. Alonso, Universidad Aut onoma de Barcelona, Spain) [11]. Integrated waveguides can be considered as a basis for direct optical detection techniques using label-free approaches – as demonstrated with examples for proteins (C. Hoffmann, Fraunhofer Institute, Freiburg, Germany) – or micro refractometry, another approach in comparison with surface plasmon resonance (R.E. Kunz, CSEM, Neuch^atel, Switzerland) [12]. Techniques for measuring the composition of the intra-cellular environment are important for an understanding of the mechanisms of cell function and cell behaviour. The development of nanosensors selective to glucose, oxygen, zinc, and calcium allows strategies for measuring analytes in the intra-cellular environment (J.W. Aylott, University of Hull, UK) [13]. Another lecture in this session by T. Vo-Dinh (Oak Ridge National Laboratory, USA) [14] demonstrated recent results of nanosensors for monitoring molecular signalling pathways in a single living cell. For this purpose, surface-enhanced Raman scattering and nanosensors for in vivo analysis of single cells have been developed. The first results for such an approach were presented. Dynamic fluorescence measurements were used to determine the concentration of living immobilised cells (O. Podrazky, Academy of Sciences of the Czech Republic) [15]. Further improvement in array biosensors for food safety could be demonstrated by F.S. Ligler (Washington, DC, USA) [16]. This multi-analyte approach was discussed by a group in Dublin; O. McGaughey used waveguides and stamp printing or pin printing and simple light emitting diode (LED) as an excitation source. This means major requirements for the fields such as food and environmental quality controls as well as biomedical diagnostics could be met [17]. Confocal total http://www.elsevier.com/locate/trac
xiii
Meeting reports
internal reflection fluorescence (TIRF) microscopy was used to detect single-molecule hybridisation at surfaces (T. Ruckstuhl, University of Zurich, Switzerland) [18]. Another invited lecture was dedicated to chemosensing and started with a lecture by G.J. Mohr (University of Jena, Germany) [19], in which he discussed chromoand fluoro-reactands as indicator dyes that allow the optical detection of electrically neutral analytes and quality with respect to response times, and operational and shelf life. A typical application of chemical interaction processes was presented by S. Busche (University of Tuebingen, Germany), who demonstrated enantiomeric separation by polymeric chirasil-calix layers with optical sensing devices [20]. The technical session was introduced by a survey of the commercial status of planar waveguide technologies with DNA and protein microarrays coming from Zeptosens in Switzerland [21]. In this session, companies taking part in the industrial exhibition presented results from this field of application, namely Osmetech, Ocean Optics, Interlab, and Biacore. Fluorescent nanocrystals as ultra-bright time resolved sensors were presented by a group from Grenoble, France (R.B. Pansu) [22], spin-coating a mixture of fluorescent dye with a silane precursor over microscope cover slips. Time-resolved laser-induced fluorescence measurements can provide high spatial and temporal resolution for the determination of contaminants (e.g., in coastal sea water) (R.F. Chen, Boston, USA) [23]. In situ fluorescence sensors have been developed by the environmental coastal and ocean sciences at the University of Massachusetts, using a fibre optic fluorescence sensor system. For some years, molecular imprinting has been considered as a new approach for optical sensing, combining high stability with a certain degree of selectivity, attempting to substitute biomolecular layers. Recent developments were presented by S. Piletsky (Cranfield University, UK) [24]. Incorporating reactive dyes into molecularly imprinted polymers will result in highly sensitive optochemical sensors, as demonstrated by K. Haupt (Compiegne University of Technology, France) [25]. Oxygen is seen as an essential molecule in many applications in life sciences by technology and medicine. Luminescence quenching is a method to determine the oxygen constant, and D.B. Papkovsky (University College Cork, Ireland) [26] lectured on a newly developed cell-respirometric screening technology that allows high through-put screening applications, low volume and high sensitivity platforms, and the monitoring of respiration of small organisms and single cells. In this session, applications for water analysis were presented, such as the automatic water analyser computer supported system (AWACSS) by G. Proll (University of Tuebingen, Germany) [27], who demonxiv
http://www.elsevier.com/locate/trac
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004
strated extremely low limits of detection in real water samples. The water sensing application using IR-ATR spectroscopy by G.T. Dobbs [28] involved in situ monitoring in a harsh aquatic environment. Another approach to monitoring sea water using fibre-optic optodes was presented by A. Gonz ales-Cano, who took care of the problems of salinity, temperature and pressure [29].
4. Conclusion The two parallel sessions often meant that participants were forced to choose between two interesting lectures. However, the large number of posters, which, in many cases, added to the lectures allowed all visitors to get a wonderful survey of the present state of the art in optical sensing regarding transduction technology, various sensitive layers and applications. The involvement of industry in attending the meeting, taking part in the exhibition and giving technology-oriented lectures demonstrated the high degree of interest of the community in the results in optical sensing. Europt(r)ode has gained scientific standing and attracted interest from industry because of the application-oriented oral presentations and posters. It was especially gratifying to meet young scientists and graduate students attending the poster sessions. It resulted in long discussions, even preventing participants from enjoying time in the cultural centre of Madrid. This conference is successful, and will be next held when Europt(r)ode VIII takes place in Tuebingen, Germany, 2–5 April 2006 [30].
References [1] K. Cammann, Phys. Chem. Chem. Phys. 5 (2003) 5159. [2] D. Erickson, D. Li, U.J. Krull, Anal. Biochem. 317 (2003) 186. [3] J.F. Fernandez-Sanchez, A. Segura-Carretero, J.M. Costa-Fernandez, N. Bordel, R. Pereiro, C. Cruces-Blanco, A. Sanz-Medel, A. Fernandez-Gutierrez, Anal. Bioanal. Chem. 377 (2003) 614. [4] S.K. Deo, E.A. Moschou, S.F. Peteu, L.G. Bachas, S. Daunert, P.E. Eisenhardt, M.J. Marc, Anal. Chem. 75 (2003) 206A. [5] S. Sasaki, S. Ozawa, D. Citterio, K. Yamada, K. Suzuki, Talanta 63 (2004) 131. [6] G.J. Mohr, G. Zhylyak, T. Nezel, U.E. Spichiger-Keller, N. Kerness, O. Brand, H. Baltes, U.W. Grummt, Anal. Sci. 18 (2002) 109. [7] Book of Abstracts for the Seventh European Conference on Optical Chemical Sensors and Biosensors: Europt(r)ode VII, Madrid, Spain, 2004. [8] N. Gajovic-Eichelmann, E. Ehrentreich-Forster, F.F. Bier, Biosens. Bioelectron. 19 (2003) 417. [9] J.T. Bradshaw, S.B. Mendes, N.R. Armstrong, S.S. Saavedra, Anal. Chem. 75 (2003) 1080. [10] D. Stadnik, A. Dybko, Analyst (Cambr., UK) 128 (2003) 523.
Trends in Analytical Chemistry, Vol. 23, No. 7, 2004 [11] M. Puyol, S. Miltsov, I. Salinas, J. Alonso, Anal. Chem. 74 (2002) 570. [12] K. Cottier, M. Wiki, G. Voirin, H. Gao, R.E. Kunz, Sensors Actuators B 91 (2003) 241. [13] J.W. Aylott, Analyst (Cambr., UK) 128 (2003) 309. [14] L.R. Allain, T. Vo-Dinh, Anal. Chim. Acta 469 (2002) 149. [15] R. Vankova, G. Kuncova, O. Podrazky, A. Gaudinova, Th. Vanek, Hemijska Industrija 57 (2003) 632. [16] F.S. Ligler, C.A. Rowe Taitt, L.C. Shriver-Lake, K.E. Sapsford, Y. Shubin, J.P. Golden, Anal. Bioanal. Chem. 377 (2003) 469. [17] S. Aubonnet, H.F. Barry, C. von Bueltzingsloewen, J.-M. Sabattie, B.D. MacCraith, Electron. Lett. 39 (2003) 913. [18] T. Ruckstuhl, M. Rankl, S. Seeger, Biosens. Bioelectron. 18 (2003) 1193. [19] G.J. Mohr, Sensors Actuators B 90 (2003) 31. [20] B. Kieser, C. Fietzek, R. Schmidt, G. Belge, U. Weimar, V. Schurig, G. Gauglitz, Anal. Chem. 74 (2002) 3005.
Meeting reports [21] Patent Application WO 2003-EP10626 20030924; PCT Int. Appl. 2004, J. Schrenzel, P. Francois, Y. Charbonnier, J.G. Jacquet, D. Utinger, G.M. Kresbach, A. Abel, M. Ehrat. [22] L. Choutteton, P. Denjean, R.B. Pansu, Phys. Chem. Chem. Phys. 1 (1999) 2463. [23] R.F. Chen, Y. Zhang, P. Vlahos, S.M. Rudnick, Top. Stud. Oceanogr. 49 (2002) 4439. [24] I. Chianella, S.A. Piletsky, I.E. Tothill, B. Chen, A.P.F. Turner, Biosens. Bioelectron. 18 (2003) 119. [25] K. Haupt, Anal. Chem. 75 (2003) 376A. [26] J. Hynes, S. Floyd, A. Soini, R. O’Connor, D.B. Papkovsky, J. Biomol. Screen. 8 (2003) 264. [27] J. Tschmelak, M. Kumpf, G. Proll, G. Gauglitz, Anal. Lett. 37 (2004) 1701. [28] B. Mizaiko, Anal. Chem. 75 (2003) 258A. [29] European project MISPEC, EVK3-2000-00519. [30] Available from:
Quality adopted throughout speciation Report on the Third International Conference on Trace Element Speciation in Biomedical, Nutritional and Environmental Sciences, held in Neuherberg, Germany, 10–13 May 2004
Bernhard Michalke *, Peter Schramel 1. Introduction The Third Speciation Conference, held at the GSF National Research Center for Environment and Health, was the third in this series, which started in 1998, and was also a continuation of the six ‘‘International Workshops on Trace Element Analytical Chemistry in Medicine and Biology’’ that were held at GSF between 1980 and 1990.
chemistry used for speciation’’ were selected as new fields. Again, the use of speciation throughout, in the sense of Templeton et al. [1], was stressed. To provide a scientific framework, eight sessions were planned, each introduced by a plenary lecture delivered by experienced scientists in their respective fields and chaired by colleagues well known in speciation (Table 1). 3. Results
2. Aims The Third Speciation Conference generally aimed to highlight the state of the art in element speciation and to show the ‘‘hot spots’’ in this field. Topics that were of greater interest in 2001 were selected as well as others, which had been recognized in the last three years to be of future interest. Such topics were ‘‘Increased use of quality-control approaches’’ and ‘‘Investigations on species preservation during extraction procedures for handling solid samples’’. In addition, ‘‘Speciation in clinical chemistry’’ and ‘‘Techniques from organic *Corresponding author. E-mail: [email protected]
0165-9936/$ - see front matter
doi:10.1016/S0165-9936(04)00737-X
Our invitation to contribute to this conference was accepted by about 110 participants from 30 countries all over the world, of which 65 contributed with a lecture or a poster presentation. For evaluation of the contributions, the scientific committee strictly followed the definitions about speciation [1], so they were not discussed as they were already accepted as a basis during the conference. Fig. 1 shows an overview of the number of contributions per topic, also in comparison with previous Speciation Conferences. However, it must be noted that a considerable number of papers covered more than one topic (e.g., many were applying quality control (QC) experiments to their investigations, which were assigned to different topics, so QC in speciation (as such and ‘‘hidden’’ in other topics) xv